WORLDBANKTECHNICALPAPERNUMBER286 9 X ENERGY SERIES Clean Coal Technologies for Developing Countries E. Stratos Tavoulareas Jean-Pierre Charpentier RECENT WORLD BANK TECHNICAL PAPERS No. 205 Xie,Kuiffner,and LeMoigne, UsingWaterEfficiently:TechnologicalOptions No. 206 The World Bank/FAO/UNIDO/Industry Fertilizer WorkingGroup, WorldandRegionalSupplyand Demand BalancesforNitrogen,Phosphate,andPotash,1991/92-1997/98 No. 207 Narayan, ParticipatoryEvaluation:Toolsfor ManagingChangein WaterandSanitation No. 208 Bindlish and Evenson, Evaluationofthe PerformanceofT&V Extensionin Kenya No. 209 Keith, PropertyTax:A PracticalManualforAnglophoneAfrica No. 210 Bradley and McNamara, editors, Livingwith Trees:PoliciesforForestryManagementin Zimbabwe No. 211 Wiebers,IntegratedPestManagementand PesticideRegulationin DevelopingAsia No. 212 Frederiksen, Berkoff,and Barber,WaterResourcesManagementinAsia, Volumel: MainReport No. 213 Srivastava and Jaffee, BestPracticesforMovingSeedTechnology:NewApproachesto DoingBusiness No. 214 Bonfiglioli,Agro-pastoralismin Chadasa StrategyforSurvival:An Essayon the Relationshipbetween Anthropologyand Statistics No. 215 Umali, Irrigation-InducedSalinity:A GrowingProblemforDevelopmentandthe Environment No. 216 Carr, ImprovingCashCropsin Africa:FactorsInfluencingtheProductivityof Cotton,Coffee,andTeaGrownby Smallholders No. 217 Antholt, GettingReadyfortheTwtenty-FirstCentury:TechnicalChangeandInstitutionalModernizationin Agriculture No. 218 Mohan, editor, BibliographyofPublications:TechnicalDepartment,AfricaRegion,July 1987toDecember1992 No. 219 Cercone, Alcohtol-RelatedProblemsasanObstacletothleDevelopmentofH1umanCapital:IssuesandPolicyOptions No. 220 Kingsley,Ferguson, Bower, and Dice,ManagingUrbanEnvironmentalQualityin Asia No. 221 Srivastava,Tamboli,English,Lal,and Stewart.ConservingSoilMoistureandFertilityintheWarmSeasonallyDryTropics No. 222 Selvaratnam, Innovationsin HigherEducation:Singaporeat theCompetitiveEdge No. 223 Piotrow, Treiman, Rimon,Yun,and Lozare, Strategiesfor FamilyPlanningPromotion No. 224 Midgley, UrbanTransportinAsia:An OperationalAgendafor the 1990s No. 225 Dia,A GovernanceApproachto CivilServiceReformin Sub-SaharanAfrica No. 226 Bindlish, Evenson, and Gbetibouo, EvaluationofT&V-BasedExtensionin BurkinaFaso No. 227 Cook, editor, InvoluntaryResettlementin Africa:SelectedPapersfroma Conferenceon Environmentand SettlementIssuesin Africa No. 228 Webster and Charap, The EmergenceofPrivateSectorManufacturingin St. Petersburg:A SurveyofFirms No. 229 Webster,TheEmergenceofPrivateSectorManufacturingin Hungary:A SurveyofFirms No. 230 Webster and Swanson, TheEmergenceofPrivateSectorManufacturingin theFormerCzechand SlovakFederal Republic:A Survey ofFirms No. 231 Eisa,Barghouti, Gillham, and Al-Saffy,CottonProductionProspectsfortheDecadeto 2005:A GlobalOverview No. 232 Creightney, Transportand EconomicPerformance:A Surveyof DevelopingCountries No. 233 Frederiksen, Berkoff,and Barber,Principlesand PracticesforDealingwith WaterResourcesIssues No. 234 Archondo-Callao and Faiz, EstimatingVehicleOperatingCosts No. 235 Claessens, RiskManagementin DevelopingCountries No. 236 Bennett and Goldberg, ProvidingEnterpriseDevelopmentand FinancialServicesto Women:A DecadeofBank Experiencein Asia No. 237 Webster,TheEmergenceof PrivateSectorManufacturingin Poland:A SurveyofFirms No. 238 Heath, LandRightsin COted'lvoire:SurveyandProspectsforProjectIntervention No. 239 Kirmani and Rangeley,InternationalInlandWaters:Conceptsfor a MoreActive WorldBankRole No. 240 Ahmed, RenewableEnergyTechnologies: A ReviewoftheStatus andCostsof SelectedTechnologies No. 241 Webster,Newly PrivatizedRussianEnterprises No. 242 Barnes, Openshaw, Smith, and van der Plas, WhatMakesPeopleCookwithtImprovedBiomassStoves? A ComparativeInternationalReviewofStovePrograms (List continues on the inside back cover) WORLDBANKTECHNICALPAPERNUMBER286 ENERGYSERIES Clean Coal Technologies for Developing Countries E. Stratos Tavoulareas Jean-Pierre Charpentier The World Bank Washington, D.C. Copyright © 1995 The International Bank for Reconstruction and Development/THE WORLD BANK 1818 H Street, N.W. Washington, D.C. 20433,U.S.A. All rights reserved Manufactured in the United States of America First printing July 1995 Technical Papers are published to communicate the results of the Bank's work to the development communi- ty with the least possible delay. The typescript of this paper therefore has not been prepared in accordance with the procedures appropriate to formal printed texts, and the World Bank accepts no responsibility for errors. Some sources cited in this paper may be informal documents that are not readily available. The findings, interpretations, and conclusions expressed in this paper are entirely those of the author(s) and should not be attributed in any manner to the World Bank, to its affiliated organizations, or to members of its Board of Executive Directors or the countries they represent. The World Bank does not guarantee the accuracy of the data included in this publication and accepts no responsibility whatsoever for any conse- quence of their use. The boundaries, colors, denominations, and other information shown on any map in this volume do not imply on the part of the World Bank Group any judgment on the legal status of any territory or the endorsement or acceptance of such boundaries. The material in this publication is copyrighted. Requests for permission to reproduce portions of it should be sent to the Office of the Publisher at the address shown in the copyright notice above. The World Bank encourages dissemination of its work and will normally give permission promptly and, when the reproduc- tion is for noncommercial purposes, without asking a fee. Permission to copy portions for classroom use is granted through the Copyright Clearance Center, Inc., Suite 910,222 Rosewood Drive, Danvers, Massachusetts 01923, U.S.A. The complete backlist of publications from the World Bank is shown in the annual Index ofPublications, which contains an alphabetical title list (with full ordering information) and indexes of subjects, authors, and countries and regions. The latest edition is available free of charge from the Distribution Unit, Office of the Publisher, The World Bank, 1818 H Street, N.W., Washington, D.C. 20433,U.S.A., or from Publications, The World Bank, 66,avenue d'1ena, 75116Paris, France. Cover: Coal can be cleaned at several points in its "fuel chain"- at the preparation plant (top left), inside the combuster (lower left), or at the smokestack (right). Another category of clean coal technology would replace the traditional coal combuster with a coal gasifier or other conversion process. (Illustration adapted from U.S. Department of Energy, "Clean Coal Technology: The New Coal Era" [Washington, D.C., March 19921,pp.10-1 .) 1 ISSN: 0253-7494 E. Stratos Tavoulareas isa consultant to the World Bank's Industry and Energy Department. Jean-Pierre Charpentier is a senior energy specialist in the same department. Libraryof Congress Cataloging-in-Publication Data Tavoulareas, E. Stratos, 1955- Clean coal technologies for developing countries / E.Stratos Tavoulareas, Jean-Pierre Charpentier. p. cm. - (World Bank technical paper; ISSN0253-7494; no. 286. Energy series) Includes bibliographical references. ISBN0-8213-3308-9 1. Coal-Developing countries. 2. Coal-Cleaning. I. Charpentier, Jean-Pierre. 11. Title. Ill. Series: World Bank technical paper. Energy series. TP326.D44T38 1995 662.6'23-dc2O 95-18086 CIP ENERGYSERIES No. 240 Ahmed, RenewableEnergyTechnologies:A ReviewoftheStatus andCostsofSelectedTechnologies No. 242 Barnes, Openshaw, Smith, and van der Plas, WhatMakesPeopleCookwith ImprovedBiomassStoves? A ComparativeInternationalReviewof StovePrograms No. 243 Menkeand Fazzari, ImprovingElectricPowerUtilityEfficiency:Issuesand Recommendations No. 244 Liebenthal, Mathur, and Wade,SolarEnergy:LessonsfromthePacificIslandExperience No. 271 Ahmed, Technological DevelopmentandPollutionAbatement:A Study ofHowEnterprisesareFindingAlternatives to Chlorofluorocarbons No. 278 Wijetillekeand Karunaratne, Air QualityManagement:ConsiderationsforDevelopingCountries No. 279 Anderson and Ahmed, 77TeCaseforSolarEnergyInvestments Contents Foreword................................................................ ix Abstract ................................................................ xi Acknowledgments ................................................................ xiii Abbreviations and Acronyms ................................................................ xv Executive Summary ..................................................... I Technologies Included in the Report ................................................................ I Status of Clean Coal Technologies ............................................................... . 2 Selection of Clean Coal Technology ................................................................ 6 Step 1:Select Fuel................................................................ 6 Step 2: Determine Environmental Requirements............................................. 6 Step 3: Evaluate Technologies................................................................ 6 Step 4: Perform Site-Specific Assessment If Needed ................ ...................... 7 A Hypothetical Selection Case ................................ ................................ 7 Recommendations................................................................ 10 1. Introduction ................................................................ 11 2. Precombustion and In SituTechnologies .......................................................... 13 Coal Cleaning................................................................ 13 Conventional Physical Cleaning ................................................................ 13 Advanced Coal Cleaning .......................... ...................................... 15 In Situ Technologies ................................................................ 16 Low-NO, Combustion Technologies............................................................... 16 Sorbent Injection for SO, Control ................................................................ 19 3. Postcombustion Technologies ....................................... ......................... 23 SO, Control Technologies ................................................................ 23 Duct Injection................................................................ 23 Wet Scrubbers/Flue-Gas Desulfurization ........................................................ 26 Dry Scrubbers (Spray Dryers)................................................................ 30 NO, Control Technologies................................................................ 32 Selective Noncatalytic Reductionfor NO, Control.................. ........................ 32 Selective Catalytic Reduction for NO, Control......................... ....................... 34 Combined SO,/NO, Control ......................... ....................................... 36 v General Description ................................................................. 36 Particulate Removal Technologies................................................................. 39 Electrostatic Precipitator Technology Enhancements...................................... 39 Fabric Filter (Baghouse) Technologies............................................................ 40 Hot-Gas Cleanup Technologies ................................................................. 41 4. Advanced Coal UtilizationTechnologies.......................................................... 45 Fluidized-Bed Combustion ........................ ......................................... 45 Atmospheric Fluidized-Bed Combustion......................................................... 45 Pressurized Fluidized-Bed Combustion Technology....................................... 48 Coal Gasification Technologies................................................................. 50 Integrated Gasification Combined-Cycle......................................................... 50 Coproduction of Electricity and Clean Fuels................................................... 53 Advances in Pulverized-Coal Output and Efficiency ................... ......................... 54 Technology Advances................................................................. 54 Life Extension/Rehabilitation .................................................... ............. 55 Technology Readiness ....................... .......................................... 56 Recommendation................................................................. 56 5. Relationshipbetween Environmental Regulationsand Technology Choice ............................................................... 57 6. Suitabilityof Clean Coal Technologies: A Screening Method ...................... 59 Evaluation Criteria ................................................................. 59 Relevant Technologies ................................................................. 60 7. Conclusions and Recommendations ............................................................... 63 Technology Choices lor Developing Countries..................................................... 63 Technologies for Short-Term Applications ................................. .................... 63 Technologies for Long-Term Applications...................................................... 64 Additional Recommendations lor Developing Countries...................................... 64 Recommendations for the World Bank................................................................. 65 Annex A Sample EnvironmentalRegulationsin Selected Countries .. 67 Annex BEquipment Suppliers............................................................... 73 References ............................................................... 81 vi Tables 1 Technologies Demonstrated and Commercially Available in Industrialized Countries................................................................. 3 2 Clean Coal Technologies in the Demonstration Stage ............................................ 4 3 Characteristics of Clean Coal Technologies ........................................................... 5 4 Technology and Plant Efficiency ................................................................. 6 5 Coal Types and Characteristics for Hypothetical Case ........................................... 8 6 CCT Options for Hypothetical Case ................................................................. 9 1.1 Clean Coal Technology Text Locator ................................................................ 12 2.1 Conventional Physical Coal Cleaning Technologies .................... ....................... 14 2.2 Advantages and Disadvantages of Physical Coal Cleaning ............. ................... 15 2.3 Advanced Coal Cleaning Technologies ................................................................ 16 2.4 Key Characteristics of Low-NO, Burner Technologies ................. ...................... 18 3.1 Cost Projections for Retrofit and New Construction of Flue-Gas Desulfurization Units ................................................................ 30 3.2 Capital Cost Requirements for Spray Dryers ....................................................... 32 3.3 Comparison of Combined SO2/NO Control Processes ................. ......................38 5. 1 Most Cost-Effective Processes for SO2 Removal .......................... ...................... 57 5.2 Most Cost-Effective Processes for NO, Removal .......................... ...................... 58 6.1 Clean Coal Technologies for Developing Countries .................... ....................... 61 A.I Standards of Ambient Air Quality and Emissions in Asian Countries ......... ...... 68 A.2 Air Emission Standards for Large (> 50 MW) Coal-Fired Boilers ....... .............. 69 B.1 Suppliers of Coal Cleaning Technologies ........................................................... 74 B.2 Suppliers of Low-NO, Combustion Technologies ................... ........................... 74 B.3 Suppliers of Sorbent and Duct Injection Processes ................... .......................... 75 B.4 Suppliers of Wet and Dry FGD Processes .......................................................... 76 B.5 Suppliers of SCR Systems ................................................................ 77 B.6 Suppliers of Bagfilters................................................................ 78 B.7 Suppliers of AFBC Boilers ................................................................ 79 B.8 Suppliers of IGCC Processes ............................. ................................... 79 vii Figures 2.1 Combustion and Postcombustion NO, Control Options ................ ...................... 17 2.2 Conceptual Design of a Low-NO, Burner............................................................ 17 2.3 Sorbent Injection Points .................... ........................................ I. . 20 3.1 Post-ESP Duct Injection Process Flow ................................................................ 24 3.2 SO- Removal vs. Ca/S for Pre-ESP Duct Injection without Recycling ......... ...... 25 3.3 SO- Removal vs. Ca/S for Pre-ESP Duct Injectionwith Recycling .......... .......... 25 3.4 Conventional Limestone/Lime Flue-Gas Desulfurization .............. ..................... 27 3.5 Limestone Forced Oxidation Flue-Gas Desulfurization Process ........... .............. 28 3.6 Chiyoda CT-121Flue-Gas Desulfurization Process .................... ........................ 29 3.7 Spray Dryer Flue-Gas Desulfuration Process ...................................... ................ 31 3.8 Hot- and Cold-side (Post-FGD) SCR Systems .................................. .................. 35 3.9 The SOJ/NO, Process ................................................................ 37 3.10 The SO,-NO,-ROX Box Process ................................................................ 37 3.11 Hot-Gas Ceramic Candle Filter .............................................. .................. 42 4.1 Differences between PulverizedCoal and Atmospheric Fluidized-Bed Combustion Boilers ................................................................ 46 4.2 PFBC Combined Cycle Technology ................................................................ 49 4.3 Generic Coal Gasification Reactors ................................................................ 5 1 4.4 Highly Integrated Gasification Power Plant Contiguration .............. ................... 51 4.5 Generalized Flow of Coal Gasification for Production of Fuel Gas .......... .......... 53 viii Foreword Linkages between energy and the environment are evident in all phases of energy production, conversion, and end use. They extend from highly localized effects-for example, at the level of the household-to the global level. On the local level in developing countries, the most serious energy-environment problems are the effects of emissions of particulate matter (dust and smoke), indoor air pollution arising from the use of biomass fuels, and the use of leaded gasoline. Volatile organic compounds generated mainly by automobilies and NOx emissions from power plants contribute to the smog that is prevalent in large cities. In addition, the regional and transnational problem of acid rain, caused by sulfur dioxide, is also severe. Worldwide energy-related problems include the potential for global warming, caused by the increased atmospheric accumulation of greenhouse gases such as carbon dioxide and methane; stratospheric ozone depletion, much of it caused by the release of chlorofluorocarbons, and the pollution of oceans. Transport, industry, and domestic energy use are prime sources of these environmental problems, which impose serious costs for health and productivity. To address the linkages between energy and theenvironment more effectively, a thematic group has been established within the Power Development, Efficiency, and Household Energy Division of the Industry and Energy Department. The group is focusing on the environmental issues in energy production, conversion, and use, including the relationship with energy efficiency. These linkages can be addressed in part through policies based on a mix of command- and-control and market-based instruments that help internalize the environmental costs of supply and use. The group is also exploring the scope for new, more efficient and environmentally friendly technologies, which need to be introduced in both the developing and industrialized countries. This paper focuses on the status of clean coal technologies (CCTs) and on their performance, costs, and suitability for use in developing countries. CCTs have been developed primarily to address the problem of acid rain, which arises from sulfur and nitrogen oxide emissions, but some of the technologies also reduce particulates and carbon dioxide and thus help to ameliorate local pollution and global warming. CCTs have been used primarily in the industrial countries, but the developing countries also need to evaluate them in conjunction with specific projects and the process of establishing or revising environmental regulations. The suitability of CCTs for developing countries is highly dependent on country-specific factors, such as the performance of each technology with the types of coals available in the country under consideration, present and projected levels of local pollution, local environmental regulations, and the additional financial resources required to use CCTs compared with the costs of operating conventional pulverized-coal plants. This paper makes a preliminary assessment of the suitability of CCTs that developing countries can use as a starting point for their own, more detailed assessments. Richard Stem Director Industry and Energy Department ix Abstract This report on clean coal technologies (CCTs) examines their performance, costs, and suitability for use by developing countries. The paper reviews in detail for each technology key elements including basic technological features, performance levels, commercial availability, costs of operation, time required for construction, suitability for developing countries, and issues affecting deployment. CCTs fall into three basic categories reflecting their relation to the combustion stage: precombustion technologies mainly involve the initial cleaning of coal by crushing and separating out pollution-generating impurities; in situ technologies involve altering the design and operating conditions of coal furnaces in a way that chemically or physically reduces emissions of SO2 and NO,; andpostcombustion technologies also remove S02 and NO, through the use of catalysts and other methods and may also scrub the gases produced by combustion and pass them through filters and precipitators to remove particulate matter. In addition, an emerging fourth category of CCTs must be noted: advanced coal utilization technologies. These in effect supersede the traditional stages of burning pulverized coal by using coal in integrated energy conversion processes. The report concentrates on commercially available technologies that are currently suitable and affordable for developing countries. But it also reviews more advanced demonstration-stage technologies in anticipation of both increased regulatory requirements and a drop in the costs of such technologies that would make them both necessary and practical for developingcountries sometime in the near future. Commercially available technologies reviewed are as follows: precombustion: physical coal cleaning; in situ: low-NO, combustion, advanced pulverized coal combustion, and power plant rehabilitation; postcombustion: wet and dry flue-gas desulfurization, advanced electrostatic precipitation, and bagfilters; advanced coal utilization: atmospheric fluidized-bed combustion. Demonstration-stage technologies reviewed are as follows: precombustion: advanced cleaning methods; in situ: sorbent injection; postcombustion. duct injection, selective catalytic and noncatalytic reduction, combined SOx / NOx reduction, and hot- gas cleanup; advanced coal utilization: pressurized fluidized-bed combustion, integrated gasification combined-cycle combustion. Given the wide use of coal in some developing countries, the paper is especially concerned to assist policymakers in choosing and justifying the use of appropriate and cost-effective CCTs. The report thus concludes with three brief chapters. The first of these discusses the relationship between environmental regulations and choice of technology; the next provides an initial screening method for evaluating relevant technologies; and the last presents conclusions and recommendations on technology choices and some notes on World Bank strategy for promoting dissemination of CCTs. xi Acknowledgments This report was developed by E. Stratos Tavoulareas (EnTEC, McL.ean,Virginia, USA) in close cooperation with Jean-Pierre Charpentier, of the Power Development, Efficiency, and Household Fuels Division (IENPD) of the Industry and Energy Department. Thanks are expressed to Joseph Gilling and Winston Hay (IENPD) and to Gunter Schramm (IFC) for reviewing the paper and commenting on it. The authors also would like to thank Karl Jechoutek, division chief of IENPD, for his support and guidance. The authors appreciate the assistance of Paul Wolman, who managed the editing and production of the document; John W. Hopper, who did initial copy editing and prepared most of the illustrations; and Carole-Sue Castronuovo, who carried out the word-processing tasks. The objective of the report is to provide World Bank staff and decisionmakers of World Bank member states with an up-to-date technical and economic overview of clean coal technologies available worldwide. Publications and documents circulated by the Clean Coal Technology Program of the United States Department of Energy and by the Electric Power Research Institute represented a major source of documentation. xiii Abbreviationsand Acronyms AFBC Atmospheric fluidized-bedcombustion Ca/S Calcium-to-sulfur molar ratio CCT Clean coal technology EPA U.S. Environmental Protection Agency EPRI Electric Power ResearchInstitute ESP Electrostatic precipitator FGD Flue-gas desulfurization HGCU Hot-gas cleanup IGCC Integratedgasification combinedcycle LHV Lower heating value LNB Low-NOx burner LSFO Limestone withforced oxidation NOx Nitrogen oxide OFA Overfire air O&M Operating and maintenance PC Pulverized coal PFBC Pressurized fluidized-bed combustion SCA Specific collectionarea SCR Selective catalytic reduction SNCR Selectivenoncatalytic reduction S02 Sulfurdioxide xv ExecutiveSummary Coal used for power generation accounts for more than 80 percent of the 4 billion tons of noncoking coal consumed annually worldwide. an amount that is expected to increase by an average of 2 to 3 percent per year for the next 20 years. Coal's association with local, regional, and global pollution is a cause of significant environmental concerns. Industrialized countries have adopted strict environimentalregulations that have slowed their use of coal. Developing countries, on the other hand, generally do not impose or have to meet the same emission requirements, although there is mounting pressure to reduce rural and regional pollution. During the next 10 to 20 years the use of coal for power generation will continue to increase, especially in Asia (e.g.. China and India), and it will remain a significant factor in the energy supply of Eastern Europe and the Commonwealth of Independent States (CIS). This increased use will require increasing attention to minimize the environmental impacts. Emerging clean coal technologies (CCTs) can be used effectively to reduce the environmental impact of the continued use of coal throughout the world. Although carbon emissions (CO2) cannot be reduced significantly by these technologies, emissions of sulfur dioxide (SO2), nitrogen oxides (NO,), and particulates can be reduced by 50 to 99 percent. Many of the CCTs that have been developed and commercialized in industrialized countries warrant consideration for use in developing countries. The report's main focus is on the current status of CCTs and their typical performance characteristics, costs, and suitability for use in developing countries. In addition, the report identifies the issues and barriers that need to be overcome if the technologies are to be implemented widely in developing countries. The paper is not intended as an exhaustive review of CCTs; instead, it provides selected references to more basic information on the design features of each technology. TechnologiesIncludedinthe Report The report details the statusof the following types of technologies: * Precombustion technologies. These consist mainly of physical coal cleaning. * In situ technologies. Low-NO, combustion and furnace sorbent injection are the principal in situ technologies. * Postcotm/bustion technologies. These include a variety of techniques: - Duct injection, wet and dry scrubbers (flue-gas desulfurization; FGD) for SO, control - Selective catalytic and noncatalytic reduction for NO, control - Combined SO,/NO, control 1 2 CleanCoalTechnologies - Electrostatic precipitators (ESPs), bagfilters, and hot-gas cleanup for particulate control. Advanced coal utilization techniologies. Again, several techniques are available: - Atmospheric tluidized-bed combustion (AFBC) - Pressurized fluidized-bed combustion (PFBC) - Integrated gasification combinedcycles (IGCC) - Coal-derived fuel/electricity clean fuel coproduction. Advances in conventional pulverized-coal technology are also presented. Statusof Clean Coal Technologies The important findings of the report are summarized below and in Tables 1 and 2. Table I lists technologies that have been demonstrated and used widely in industrialized countries. Table 2 lists technologies still in the development or demonstration phases. PhYsical coal cleaninig techlniologies. These are easily adaptable to developing countries and are cost-effective in most cases. Coal cleaning reduces transportation costs as well as sulfur and particulate emissions, and it improves pcwer plant reliability. Developing countries should be encouraged to adopt coal pricing policies that reflect the quality of the coal and its effects on power production costs, power plant reliability, and emissions. * LO)W-NO,burner.s.These should be included in the design specifications for all future power plants, and provisions should be made for overfire air ports. Such specifications increase power plant costs by less than US$5/kW and will result in significant savings when future regulations require further NO, reductions. * lDrYscrubbers (Table 1) and sorbent injectiotn technologies (Table 2). These offer attractive methods for moderate sulfur removal at relatively low costs. Further demonstraitionof these technologies is required indeveloping countries. * Elect rostotic precipitator technology. ESP technology has undergone significant advances. Most options have very short payback periods, and they should be considered by developing countries. Examples includethe following: - Intermittent energization: improves performance, reduces auxiliary power - Flue-gasconditioning: increases the collection efficiency of ESPs - ESP controls and energy manaigement systems: improve collection efticiency and reduce auxiliary power requirements. * Bogfilters. Bagtilters may be required in developing countries, especially if .;orbent injection, dry scrubbers, and fluidized-bedcombustion are used. * Atino.vspleric f17iilidiez-17etI-ecomrsbustion technologv. Both circulating and bubbling types ot AFBC are proven technologies at sizes below 200 MW and are well- suited for developing countries with low-grade fuels. Executive Summary 3 Advances in pulverized-coal techniiques. Significant advances have been made in improving conventional pulverized-coal technology. Particularly appropriate for developing countries are advanced techniques for rehabilitating power plants, which can increase the plant's unit output, life expectancy, and reliability. Table1 TechnologiesDemonstratedand CommerciallyAvailablein IndustrializedCountries Emissions Technology Type controlled Issues/barriers Recommendations Physical coal Pre- Sulfur and ash Coal pricing Promote coal pricing cleaning combustion Lack of environ- according to coal mental regulations quality Raise awareness of coal cleaning benefits Low-NOx In situ NO, Lack of environ- Include technology in combustion mental regulations all new boiler design specifications Wet FGD Post- Sulfur Lack of environ- Pursue FGD if combustion mental regulations environmental Highcosts regulations require Demonstration may high SO2 removal be needed Dry FGD Post- Sulfur Lack of environ- Promote demonstra- (commercial combustion mental regulations tion for both high- and for low-sulfur Demonstration low-sulfur coals coals) needed Advanced Post- Particulates Lack of environ- Promote awareness in ESP combustion mentalregulations developing countries Lack of awareness Bagfilters Post- Particulates Lack of environ- Promote selectively, combustion mental regulations especially where Highercost than sorbent-basedtech- ESPs nologies are utilized AFBC Advanced Sulfur and Higher cost than PC Demonstration needed (commercial combustion NO, withoutFGD for some coals (e.g., up to 200 Lack of environ- India) MW) mental regulations Advanced In situ Heat rate/CO2 Lack of incentives Promote through pulverized- improvement, for better plant per- avvareness-building coal and as well as unit formanceand relia- andfinancing of life power plant reliability bility extensionprograms rehabilitation Lack of awareness Note: FGD= flue-gasdesulfurization;AFBC= atmosphericfluidized-bedcombustion,ESP= electrostatic precipitator. 4 Clean Coal Technologies Of the technologies included in Table 2, sorbent and duct injection are particularly suitable for developing countries because of the moderate sulfur removal and low costs. However, industrialized countries do not emphasize these technologies as much as the high-sulfur removal technologies, and an initiative based in developing countries may be needed to demonstrate them and adapt them to local requirements. PFBC and IGCC technologies also may be suitable for developing countries, but they need further demonstration. If the technology-related risks could be mitigated (e.g., through participation and risk-sharing by the equipment suppliers), demonstration projects in developing countries would be appropriate. Table2 Clean CoalTechnologiesintheDemonstrationStage Emissions Technology Type controlled Issueslbarriers Recommendations Advanced Pre- Sulfur and Coal pricing Monitor progress in cleaning combustion ash Lack of environmental developed countries regulations Still in development Sorbent In situ Sulfur Demonstrationneeded in Promote developing injection developing countries country demonstration Duct Post- Sulfur Demonstrationneeded in Promotedeveloping injection combustion developing countries country demonstration SNCR Post- NO, SNCR needs further Monitor experience in (demon- combustion demonstration developed countries strated up to 300 MW) SCR Post- NO, Lack of environmental Pursue SCR if (commercial combustion regulations environmental for low- Highcosts regulation7srequire sulfur coals) Demonstrationneeded highNO., removal; demonstration needed Combined Post- Sulfur and Early development stage Monitor progress in SO,/NO, combustion NO, developed countries Hot-gas Post- Particulates Tied to PFBC and IGCC Monitor progress in cleanup comnbustion developed countries PFBC Advanced Sulfur, NO,, Demonstrationneeded Promote and CO, demooistration IGCC Advanced Sulfur, NO,, High costs Monitor and CO- Demonstrationneeded deinooistrations Note: Advancedcoalcleanincincludesadvancedphysical.chemical,and biologicalcleaningmethods. SNCR = selective noncatalyticreduction:SCR = selectivecatalytic reduction; PFBC = pressurized fluidized-bedcombustion:IGCC= integratedgasiticalioncomilbined-cycle. 6 Clean Coal Technologies Table4 Technologyand PlantEfficiency Technology Plant efficiency (%, LHV) PC with ESP (reference technology) 35-38 PC with wet FGD 34-37 AFBC 35-38 PFBC 38-45 IGCC 38-45 Note: PC = pulverizedcoal:ESP = electrostaticprecipitator;FGD= flue-gasdesulfurization;AFBC= atmosphericfluidized-bedcombusion;PFBC= pressurizedfluidized-bedcombusion;IGCC= integrated gasificationcombinedcycle. Selection of Clean Coal Technology The most suitable technology for each project depends greatly on the characteristics of the coal, the required environmental performance (SO2, NO,, and particulate control), and the cost-effectiveness. Therefore, selection of a technology should include the steps detailed below. Step 1:Select Fuel The key elements in fuel selection will be to determine proximate, ultimate, and ash analysis, heating value and ash softening temperatures, and variability of coal characteristics. In addition, it will be necessary to decide on the desirable fuel flexibility of the power generation facility. For example, one must determine whether the facility is to burn only one fuel throughout its operating life or whether it should be capable of burning other fuels as well. Step 2: Determine EnvironmentalRequirements Environmental requirements may be dictated by national, regional, or local regulations, and they may be either emnissions (effluent or poinit-source) standards or ambient air q(l(litvI stanzd(ards. Emissions standards apply directly to the new source (power generation facility). If air quality standards are used, the emission inventory, dispersion, and impact of the added pollutants on air quality must be assessed, and a maximum allowable level will be determined for each major pollutant (SO2, NO,, and particulates) based on applicable environmental standards. Step 3: Evaluate Technologies An evaluation of the technology should consider the following criteria: SuitabilitN*of tihetechnology to ch1ara,cteristics of t/ecoal. For example, entrained gasification is not suitable for many Indian coals without significant reduction of their high ash content (coal cleaning). ExecutiveSummary 7 * Technology readiness. The technology should be in use in a few (at least five) commercial-size plants and should have demonstrated its performance, cost- effectiveness, and reliability. * Environmental requirements. The environmental criteria of the project must be satisfied, and technologies not meeting the requirements screened out. * Cost-effectiveness. Finally, the most cost-effective technologies that meet the above requirements should be selected (in many cases, several technologies will qualify). Step4: PerformSite-SpecificAssessmentIfNeeded Consideration of site requirements is particularly important when more than one process will satisfy technological, environmental, and cost criteria. A HypotheticalSelectionCase A hypothetical example of the selection process is provided below. Step 1 Power Company X plans to build a 400 MW base-load power plant. Four alternative plant sites and three coals (see Table 5) have been identified. Coal A is a high-ash indigenous coal cleaned to reduce ash and sulfur content; coal B is a high- ash/high-sulfur indigenous coal; and coal C is a low-ash/low-sulfur imported coal. Step2 Review of the federal and local environmental regulations identified the following requirements for each of four possible power plant sites: * Site #1: 95 percent particulate removal * Site #2: 95 percent particulate removal and less than 800 ppm S02 (1.85 lbs SO2 /MBtu) * Site #3: 95 percent particulate removal, less than 520 ppm SO2 (1.2 lbs SO2 /MBtu), and 50 percent NO, removal * Site #4: 95 percent particulate removal, less than 90 ppm SO2 (0.2 lbs SO2 /MBtu), and 80 percentNO, removal. Step3 For site #1, because no SO2 and NO, emission removal requirements are in force, the least-cost option is the pulverized-coal plant with electrostatic precipitators (ESP) firing the lowest-cost coal (coal B). The capital costs of this option are $1,000/kW with a coal price of $20 per ton, giving a levelized cost of electricity of 46 mills/kWh (Table 6). 8 CleanCoalTechnologies For site #2, Coal A (cleaned to reduce the sulfur content to 1.5percent) burned in a pulverized-coal plant equipped with ESP satisfies the environmental requirements of Site #2 and is the least-cost option. Sulfur emissions from such a plant are 775 ppm SO2 (1.80 lbs SO2 /MBtu). Coal cleaning adds $4 per ton in the cost of the coal ($24 per ton delivered to the plant) and results in 47 mills/kWh of levelized cost of electricity (Table 6). For site #3, four technology types satisfy the environmental requirements: pulverized-coal plant with ESP firing imported low-sulfur coal (coal C); pulverized-coal plant with ESP and wet FGD firing coal A; atmospheric fluidized-bed combustion with bagfilter firing coal B; and pressurized fluidized-bed combustion with hot-gas cleanup firing coal B. Although the capital costs of these technologies for Site #3 vary (see Table 6), the levelized costs range from 53 to 58 mills/kWh (which is within the level of accuracy of the estimates). Table 5 Coal Typesand Characteristics forHypothetical Case CoalA (hiiglh- CoalB (1higli- CoalC (low- Measfre asll/n1iediwniii-s(llisr) cislhl/higl-sulfur) as/illow-sulftur) Proximateanalysis Volatiles(%) 16.8 12.8 44.0 Fixed carbon(%) 52.1 41.1 48.3 Moisture(%) 4.5 4.0 15.0 Sulfur(%) 1.5 3.3 1.0 Ash(%) 25.1 38.8 7.7 Heafingvalue (Btu/lb) 8,200 7,505 10,270 (Kcal/Kg) (4,550) (4,165) (5,700) UncontrolledSO2 775 1,890 430 emissionsppm (lbs/MBtu) (1.8() (4.4) (1.0) Coal price($/ton) 24 20 45a ;dimportedcoal prices ranoe fromil30 to 60$/metric ton. See IEA. "Coal Information 1992"' and Jechoutek and others. "StearnCoal tor Power and Industry/Issues and Scenarios., World Bank, October 1992. Step 4 In the case of sites#I and#2. a clear technologychoice emerges. However, in the case ot site #3. the selection ol the most appropriate technology will depend on other site- specific considerations, advantages, and disadvantages. For example: * Although imported coal has the lowest levelized cost, it may be eliminated because of its adverse impacts on foreign exchange requirements. Executive Summary 9 * If it is desirable to burn coal B as well as coal A, the design of the PC with wet FGD plant will need to be modified, adding to its capital and levelized costs, and making it less competitive. Also, the pulverized-coal plant may not be able to burn coal with an ash content greater than 30 to 40 percent and still meet the environmental requirements. * AFBC can burn other coals, including low-quality/lower-cost coals, but it generates more solid waste. * PFBC has characteristics similar to AFBC, but it has higher technical risks because it is still in the demonstration stage. The importance of these factors for Site #3 needs to be evaluated in more detail before a final selection is made regarding the most suitable and cost-effective technology. Therefore, a site-specific feasibility study is required. Table6 CCTOptionsforHypotheticalCase O&M Fuel Levelized Capital Platit Coalprice cost cost cost Emission cost efficiency ($/ton, (mills! (miills! (millsl Techinologyoptioti requirement ($/kW) (%, LHV) delivered) kWh kW) kW) PC with ESP (coal B) 95% particulate 1,000 36 20 9 11 46 removal PC with ESP +coal 1.85lbs SO2/MBtu, 1,000 36 24 9 13 47 cleanino (coal A) 95% particulate removal PC with ESP and 1.2lbs SO2/MBtu, 1,000 36 45 9 19 53 low-NOx burners 50% NOX,95e% (coal C) particulate removal PC with ESP. low- 1.2lbsSO2/MBtu, 1,200 35 24 10 14 54 NOXburners and wet 50% NOX,95% FGD (coal A) particulate removal AFBC with bagfilter 1.2lbs SO2/MBtu, 1,400 36 20 11 11 58 (coal B) 50% NOX,95% particulate removal PFBC with hot-gas 1.2lbs SO2/MBtu, 1.350 42 20 11 9 55 cleanup (coal B) 50% NOX- 95% particulate removal IGCC (coal C) 0.2 lbs S02IMBtu, 1,600 41 45 12 17 70 80% NOX,98% particulate removal Note. Levelized cost is calculated using the following assumptions: capacity factor = 65 percent; discount rate = 12 percent; construction duration = 4 years; plant life = 30 years. PC = Pulverized coal; ESP = electrostatic precipitator; FGD = flue-gas desulfurization; AFBC = atmospheric fluidized bed combusion; PFBC = pressurized fluidized-bed combusion; IGCC= integrated casificationcombined cycle. 10 Clean Coal Technologies For site #4, integrated gasification combined cycle (IGCC) using coal C is the only technology that meets the SO2 and NO, removal requirements. Coal C is selected because it is more suitable for the entrained gasification processes, which are closer to commercialization. Coals with high ash content (above 15 to 20 percent) require fluidized-bed gasification processes, which have not been fully demonstrated. Recommendations In general, for the present and near-term future environmental regulations of most developing countries, the most suitable andcost-effective technologies are the following: * Coal cleaning * Sorbent injection * Dry scrubbers * Atmospheric fluidized-bed combustion * Electrostatic precipitators. For NO, control, low-NO, burners provide a low-cost solution and should be adopted by all new power plants. Also, significant advances have been made in ESP technology and pulverized-coal combustion that should be considered for both new and retrofit applications. For other clean coal technologies, however, a site-specific technology screening, including a risk assessment, is recommended. 1 Introduction This report seeks to provide a general update on clean coal technologies, and, in particular, on their performance, costs, and suitability for developing countries. The technologies are categorized broadly according to their location relative to the boiler/combustion stage: * Precombustion technologies. These involve mainly coal cleaning. * In situ technologies. These comprise low-NO, combustion and furnace sorbent injection. * Postcombustion technologies. These include duct injection; wet and dry scrubbers for S02 control; selective catalytic and noncatalytic reduction for NO, control; combined SO2/NO, control; and electrostatic precipitators, bagfilters, and hot-gas cleanup for particulate control. e Advanced coal utilization technologies. These include atmospheric and pressurized fluidized-bed combustion, integrated gasification combined cycle, and coproduction of coal-derived fuels and electricity. Advances in pulverized-coal plant components, thermodynamic cycle, and plant rehabilitation are also presented. The description of the pulverized-coal advances is not exhaustive; rather, it is intended to raise the level of awareness of this technology. The report provides a summary of the key elements associated with each technology, including a brief description of the technology, along with some discussion of its performance, commercial availability and costs of operation, construction time, suitability for developing countries, and issues affecting deployment. The capital and O&M costs reflect mostly costs in the U.S. and Europe, but they are applicable to developing countries as budgetary cost estimates for technology screening purposes. Annex A provides more detailed information on selected technologies. The main report is organized into seven chapters, including this introduction. Chapter 2 reviews the status of precombustion and in situ coal technologies. Chapter 3 covers posteombustion technologies, and chapter 4 discusses advanced lower-polluting technologies. Chapter 5 is devoted to the link between technology selection and 11 12 Clean Coal Technologies environmental requirements, especiall lertains to developing countries. Chapter 6 provides an example of a method hat can be used to evaluate clean coal technologies on the basis of diffL I riteria, including technology readiness, characteristics of local coals, environm i .gulations. costs, and indigenous capability. Chapter 7 presents conclusions and rec A dations. Two annexes are also incih Annex A provides a summary of the environmental regulations of industria Ce untries and developing countries. Annex B comprises several lists of equipment I rs. It is not complete, however, because it includes only the organizations for wi ormation was readily available-mainly the U.S. suppliers. Table 1.I provides a guide to ti ic s information on specific technologies. Table1.1 Clean, -)a' achnologyTextLocator Reportlocation Technology 2 NO- CO2 Pat-ticulates (page) Coal cleaning x x 13 Low-NOXcombustion x 16 Sorbent injection x 19 Duct injection x 23 Wet FGD (scrubbers) x 26 Dry FGD (spray dryers) x 30 SNCR x 32 SCR x 34 Combined SO,/NO, x x 36 Electrostatic precipitators x 39 Fabric filter (baghouse) x 40 Hot-gascleanup x 41 Atmospheric fluidized-bed combustion x x 45 Pressurized fluidized-bed x x x 48 Integrated gasification x x x 50 Clean coal-derived fuels x x x 54 Advances in pulverized-coIi ___ x 54 Note: FGD = flue-gas desulfurization; SNCR = selective noncatalytic reduction; SCR = selective catalytic reduction; NOX= nitrogen oxides; SOX- sulfur oxides. 2 Precombustionand InSituTechnologies Precombustion technologies basically involve "cleaning" of selected impurities- such as ash, sulfur, and moisture-from the coal before it reaches the furnace. In situ technologies, on the other hand, involve either pollution-reducing modifications to the design and operating conditions of the burner system or injection of a "sorbent" (a substance that takes up and holds impurities by adsorption or absorption) at some phase of the combustion process. Coal Cleaning Coal cleaning originally focused on removing ash and moisture from coal to reduce transportation costs and improve the power plant efficiency. More recently, however, coal cleaning in the industrialized countries has focused on removing sulfur to reduce acid-rain-related emissions. Coal-cleaning methods may be classified into conventional physical cleaning and various advanced cleaning methods, including advanced physical cleaning, aqueous phase pretreatment, selective agglomeration, and organic phase pretreatment. Of these alternatives, conventional physical cleaning is widely used, well proven, and highly suitable for use by developing countries. The advanced cleaning methods are mostly still in the development or demonstration stages, are noted in a brief section below. ConventionalPhysicalCleaning Conventional coal cleaning relies chiefly on gravity-based separation of inerts (ash) and sulfur compounds before the coal is pulverized and introduced into the steam generator (boiler) for combustion. Technology.Conventional cleaning usually begins with crushing of the coal to a 50 mm maximum diameter, followed by screening into coarse, intermediate, and fine particles. Crushing liberates ash-forming minerals and nonorganically bound sulfur (e.g., pyrites [FeS21). Grinding into smaller particles results in higher separation. Because mineral matter has a higher density than organic-rich coal particles, it can be separated 13 14 Clean Coal Technologies from the coarse and intermediate particles of coal bv jigs. dense-medium baths, cyclone systems, and concentrating tables (see Table 2. 1). Table2.1 ConventionalPhysicalCoalCleaningTechnologies Technologytype ______ Proces. Crushing Grinders pulverize coal, which is then screened intocoarse (< 50 mm diameter), intermediate,and fine (< 0.5 mm) particles. The crushing liberates the nonorganically bound mineral particles from the coal. Because these mineral particles are denser than the organically rich coal, they can be separated from the coal by further processing (see next items). Jigs (G) For coarse to intermediate particles Dense-medium baths (G) For coarse to intermediate particles Cyclones (G) For coarse to intermediate particles Froth flotation (G) For fines: relieson the ditferent surface properties of ash (hydrophilic) vs. coal (hydrophobic): high potential, butcurrent technologiesdo not handle the small particles efficiently. Note: G = Gravity-(density)-basedseparation. The fines (particles smaller than 0.5 mminin diameter) can be separated by the froth flotation technique, which exploits suLrfacediffcrcnces between coal and ash (coal's surface is hydrophobic. whereas ash's sur-faceis hyldiophilic). Unfortunately, although the potential for cleaning the coal fines is goreatrcthan for cleaning the coarse and intermediate coal particles, current technologies do not handle the fines efficiently. Physical cleaning cannot rernoveorganically bound sulfur that requires chemical or biological methods. Thus, the the larger the percentage of organically bound sulfur in the coal, the lower the percentage of sulfur that can be removed by physical methods. Performance. Ash removal can reach 60 percent; total sulfur removal is 10 to 40 percent, increasing in tandem with a rising percentage of pyritic (mineral) sulfur in the coal. Weight recovery (the percentage of coal retained) is 60 to 90 percent, and thermal recovery (percent ol' heating value retained) is X58o 98 pe.cent. Availability. The following points dcscribc the commercial conditions under which conventional coal cleaning is availabletoday: * Techniology readiness. Conventional coal cleaning methods are commercially available throughout the world. * Suppliers. A list of equipment suppliers is provided inAnnex B, Table B.I. * Cost-effectiveness. The cost of physical cleaning varies f'romUS$1 to US$10/ton, depending on the coal quality, the cleaning process used, and the degree of cleaning desired. In most cases, cleaning costs range from US$1 to US$5/ton. Selection of the most appropriate physical coaLlcleaning niethod and the choice of the level of cleaning desired involves balancing advantages and disadvantages (see Table Precombustion and In Situ Technologies 15 2.2). It also involves considerations such as environmental regulations (sulfur-removal requirements) and the cost of cleaned coal relative to that of naturally occurring coal of the same quality. Table2.2 Advantagesand DisadvantagesofPhysicalCoal Cleaning Advantages Disadv'antages 1Oto 40 percent lower S02 emissions Coal grinding isenergy-intensive. Higher pulverizer and boiler availability 2 to 15 percent energy loss during cleaning. (estimated: I percent imiiprovem-nentin Water-based coal cleaning methods add availability forevery 1percentdecreaseinash moistureto thecoal, which reduces boiler and content) power-plant efficiency. Lower maintenance costs (less wear and tear on coal preparation equipment and boiler) Less boiler slagging and fouling Lower dust loading of ESP/bagfilter Lower transportation costs (applicable to cleaning at the mine only) Construction.Building of the necessary equipment requires from I to 2 years (including design, manufacture, and construction). Suitability.Although the suitability of a technology requires an evaluation of the specific characteristics of each coal (e.g., percentage of pyritic vs. organically bound sulfur), most coals in developing countries can be cleaned with conventional physical cleaning methods. These technologies may need to be modified, but most developing countries, with some initial external support, have the know-how and infrastructure to accept, adapt, design, manufacture, and use these technologies. Deployment. Most developing countries have no incentive to clean coal because the price of coal does not vary with quality or with impact on power plant performance. Also, present environmental regulations in most developing countries do not encourage sulfur reduction. Advanced CoalCleaning The advanced coal cleaning methods (advanced physical, aqueous, and organic phase pretreatment and selective aglomeration) are at the early commercialization or development stages, and their cleaning effectiveness and economic attractiveness are largely untested. Because this report focuses on the near-term applicability of CCTs to developing countries, the advanced methods are merely noted in passing (see Table 2.3). 16 Clean Coal Technologies Table2.3Advanced Coal CleaningTechnologies Technologx ivpe Process Advanced physical cleaning Advanced troth flotatioin(S) Electrostatic (S) Heavy liquid cycloning (G) Aqueous phase pretreatment Bioprocessing Hydrothermal Ion exchatnge Selective agglomeration Otiscaal LICADOa Spherical AgglomerationAglofloata Organic phase pretreattrmentt Depolvymerizatiotn Alkylation Solvent swelling Catalyst addlition(e.g.. carbonyl Organic sultur renoval Note: G = gravity-(density)-hased separation; S = surface-effect-based separation. 'Trade namnestor ciniunercial processes. In SituTechnologies In situ technologies include both NO, and SO, control methods. NO, control focuses mnainly on modification of the design and operating conditions of the burner (combustion system). In situ SO, control technologies utilize injection of a sorbent (usually limestone) to capture the sulfur and remove it as a dry, solid by-product. Low-NOx Combustion Technologies NO, emissions have been linked to acid rain, photochemical smog, and tropospheric ozone (greenhouse effect). This has led to establishment of regulatory measutres and to developtnent ol technologies to reduce NO, emissions from existing and new power plants. Two general techniques are Used to reduce NO, emissions. The first involves modification of the combustion process (staged combustion) and includes low- NO, hurners (with and without overfire air IOFA]) and gas or coal reburning; these methodologies are described in this section. The second type of NO, redutction strategy involves postcombustion removal and includes selective noncatalytic NO, reduction (SNCR), selective catalytic reduction (SCR). and combined SO,/NO, removal; these methods are discussed in chapter 3. Both types are shown in Figure 2.1. Technology. Low-NO, burners (LNBs) are designed to "stage" combustion (see Figure 2.2). In this technology, a fLuel-rich combItstion zone is created by forcing additional air to the outside of the firing zone (auxilliary air) and bv delaying the combustion of coal. Reduction of 30 to 55 percent of NO, can be achieved with low-NO, burners. Advanced stage combustion technologies usc overfire air and gas or coal reburning to achieve even greater reductiolIs ot NOx. Precombustion and In Situ Technologies 17 Figure2.1 Combustionand Postcombustion NOxControlOptions SNCR (Ammoniaorureainjection) \1/ j ~~~sorbent spray ~~~~~~~~Supply tank ~ H Flyash\ Stabilized waste Figure3.4 showsconventionallimestone/limeflue-gasdesulfurization.Afterleavingthe particulateremovaldevice-a fabricfilteror ESP(topleft)-the gasentersa spraytower or absorber(top center),where it is sprayedwith a calcium-basedwater slurry. The calciuminthe slurryandtheSu2 in thefluegas formcalciumsulfiteor calciumsulfate, whichareremovedbydewateringandsettlingintoa thickener(center).The FGDwastes are usuallymixedwiththefly ashcollectedinthefabricfilteror ESPandlime ina pugmill (bottomcenter),andtheyaredisposedof inlandfills. Note: ESP= electrostaticprecipitator;FGD= flue-gas desulfurization. Often, a spare absorber is included to allow full-load operation with one absorber out of service, although the industry trend is to improve scrubber reliability and eliminate the spare module. The cost estimates presented in this report assume that one spare module is included. Presently, the largest capacity scrubber module can handle flue gas approximately equivalent to that of a 150 MW coal power plant. Limestone with forced oxidation (LSFO) is a variation of the traditional wet scrubber (see Figure 3.5). In the LSFO process, the calcium sulfite initially formed in the spray tower absorber inearly prcent oxidized to form gypsum (calcium sulfate) by bubbling compressed air through the sulfite slurry in the tower recirculation tank or in a separate vessel. Because of their larger size and structure, gypsum crystals settle and dewater better than calcium sulfite crystals, reducing the required size of by-product 28 CleanCoalTechnologies handling equipment. The high gypsum content also permits disposal of the dewatered waste without fixation. Gypsum also has a commercial value, and this needs to be incorporated into the overall assessment of the FGD processes. Figure3.5 Limestone Forced Oxidation Flue-Gas DesulfurizationProcess =0 _ Cleangasout ~~~Fabric filter 2N, +CO- +2H,O NO, +NH, +O, +H-O+(H-,) > N, +H,O Because the highest NO, reduction is achieved at temperatures between 870 and 1,200° C (1,600 to 2,2000 F), the reagent is introduced at the top and backpass of the PostcombustionTechnologies 33 boiler. Multiple injection locations may be required, especially in case of cycling units: different injection locations are used as the unit operates at a reduced load. Performance.SNCR technologies can reduce NO, emissions by 35 to 60 percent without significant impactson unit performance. Availability.The following points describe the commercial conditions under which selective noncatalytic reduction technology is available today. Technology readiness. The technology was initially demonstrated in boilers fired by oil or natural gas, but the use of SNCR in coal-fired boilers is presently under way. The technology has been demonstrated in 15 utility-scale boilers in the United States and Europe (especially in Germany and Austria). Technical issues that remain to be addressed are as follows: - Ability to satisfactorily minimize deposition of ammonium bisulfate on the air heater baskets, which plugs them. - Ammonia contamination of the ash; ammonia is odorous at concentrations as low as 20 ppm. - Release of unreacted ammonia into the environment through the flue gas ("ammonia slip"). - Generation of N2O, anozone-depleting greenhouse gas. Suppliers. Suppliers of SNCR technologies are limited; two are Nalco/Fuel Tech and Exxon Research and Engineering. Nalco's technology (NOXOUT) is marketed in the United States and other countries by licensees such as Flakt Canada Ltd.; Rertokraft AB; Research Cottrell, Inc.; RJM Corporation; Todd Combustion, Inc.; and Wheelabrator Air Pollution Control. Exxon markets its process (Thermal DeNOx) through sinilar arrangements with various organizations. * Cost-effectiveness. The cost of retrofitting a boiler with SNCR is US$10 to 20/kW, whereas incorporating SNCR in a new boiler is projected to cost US$5 to 10/kW. This difference is caused by the cost associated with modifying the existing boiler lo install the reagent injection ports. The operating costs associated with the reagent, auxiliary power, and potential adverse O&M impacts are usually on the order of I to 2 mn/kWh. Construction.Two to five weeks of outage are required to retrofit a boiler with SNCR. SuitabilityandDeployment.This technology is suitable for developing countries that require NO, reduction above and beyond what is achieved by low-NO, burners. Developing countries should monitor the progress in industrialized countries and decide whether they want to acquire the technology, depending on their NO, control regulations and the sucessful resolution of the outstanding issues mentioned above. 34 Clean Coal Technologies SelectiveCatalyticReductionforNOxControl Although selective catalytic reduction (SCR) technology is widely available for low-sulfur coal, its acceptance in developing countries is hindered by the high capital and O&M costs, the need for adaptation to different types of coal, and their generally less stringent regulations regar-dingNO, reduction. Technology.SCR is similar to SNCR inthat it uses ammonia injection in the flue gas to convert NO, emissions to elemental nitrogen and water. The key difference between SCR and SNCR is the presence in SCR systems of a catalyst, which accelerates the chemical reactions. The catalyst is needed because SCR systems operate at much lower temperatures than do the SNCR; typical temperatures for SCR are 340 to 3800 C (650 to 7200 F), compared with 870 to 1,2000C (1,600 to 2,2000 F) for SNCR. The most commonly used catalysts are a vanadiunm/titaniumformulation (V20 5 stabilized in a TiO2 base) and zeolite materials. Figure 3.8 illustrates hot- and cold-side SCR systems. Performance. SCR has a demonstrated ability to remove 70 to 90 percent of the NO, emissions from low-sulfur-firing boilers. Similar NO, reduction is expected with mediulll- to high-sulfur coals, but such performance has not been demonstrated in utility- scale boilers. Availability. The following points describe the commercial conditions under which selective catalytic reduction technology is available today. Teclinology readiniess. SCR is commercially available throughout the world for low-sulfur coal (less than 1.5 percent on a dry-weight basis). SCR has been installed and is operating in more than 30 GW of coal-fired capacity in Germany and 6 GW in Japan. In addition, Japan has more than 15GW of oil-fired capacity utilizing SCR. In the United States, the focus is on demonstrating the performance and economics of SCR in medium- and high-sulfur coals. Issues that need to be addressed are as follows: - Quantity of catalyst required to achieve a specific NO, reduction - Catalyst life (alkali and arsenic in the coal reduce the useful life of the catalyst) - Required ammonia (NH3:NO, molar ratio) to achieve a specific NO, redLuction - Percentage of unreacted ammonia released into the environment (iammonia slip") -- Conversion of SO- to SO,; most catalysts convert 0.5 to 1.5 percent of the incomingSO, toSO3, which affects NOXremoval efficiency - Impact of SCR on unit reliability, especially the problem of air heater plugging - Overall cost-effectiveness, relative to other NOXcontrol options. Postcombustion Technologies 35 Figure3.8 Hot-andCold-side(Post-FGD)SCRSystems Fluegas fromboiler ~~~~~Ammonia Hot-sideSCR injection / / _ | _ ~~SCR Toparticulate Economizer | controlsystem ~~| _ LL ~~~and stack Airheater Heat Gasfrom scrubber Post-FGDSCR Recuperative heatexchanger SCR Stack Figure 3.8 showsthe SCR,locatedeither betweenthe economizerand the air heater ("Hot-side"SCR,top halfof figure)or downstreamfromtheparticulateremovalandFGD ("Cold-side"or "Post-FGD"SCR, bottom half). Hot-side SCRs operate at flue-gas temperatures of 340 to 380° C (650 to 720° F). Post-FGD SCRs operate at approximately330' C (625°F),andthustheflue gas mustbe reheatedbefore it enters theSNCR. Note: FGD= flue-gasdesulfurization;SCR= selectivecatalyticreduction. Hot-sideSCR systemsare installedbetweenthe economizerand the air heater; therefore,theyrequireextensivemodificationsof the boilerbackpass. Lackof available space is veryoften a constraint,and mayresultin designcompromisesand/orincreased costs. Post-FGDSCRs are installeddownstreamof the particulatecontrol and FGD, wherethereis morespace. To illustratethe spacerequirementsof SCRs: a 500MWunit needsa totalof 38m x 30m planareax 30m high(125ft. x 100ft. x 100ft.), including structuralsteel,stairs,walkways,andso on. * Suppliers. Alistof suppliersis providedinAnnexB, TableB.5. 36 CleanCoalTechnologies Cost-effectiveenes.s.Capital costs range from US$50 to 150/kW,depending on the required NO, emission reduction, unit layout (available space and interferences), catalyst Linitprice, cost of ammonia, and type of SCR (hot-side vs. post-FGD). Hot-side SCRs typically cost US$50 to 100/kW, whereas post-FGD SCRs cost US$120 to 150/kW. O&M costs for SCR are expected to add 4 to 8 m/kWh, depending on the catalyst life (typically 3 to 5 years) and the catalyst cost (typically 300 to 600 US$/cu. ft.). Construction. Hot-side SCR retrofits require 2 to 3 months outage, whereas post- FGD SCR retrofits require 3 to 6 weeks outage. Suitability.Technically, SCRis suitable for coal-fired power plants in developing countries. However, technology demonstration and potential adaptation to unique coal characteristics may be reqcLui-ed. Fulthermore, environmental regulations in developing countries often do not reCuiLrethe 80 to 90 percent level of NO, reduction achieved by SCR. Deployment. The main factors that prevent the use of SCR technology in developing countries arc the lack of regulations requiring high NO, reduction (80 to 90 percent) and the high cost of SCR relative to other options (low-NO, burners and SNCR). CombinedSOX/NOxControl GeneralDescription More than a hundred processes are under development that combine SO2 and NO, removal to reduce the design and operating complexity of these systems. The intent is to provide a cost-effective alternative to the combination SCR-wet FGD. Technology. C'ombined SO2/NO, control processes include adsorption/ regeneration, flue-gas irradiationi,wet scrubbingwith additive for NO, removal, gas/solid catalytic operations, electrocheiical processes, and dry alkali processes. Each category comiprises maniy processes, and silnce the technologies are only in the development stage, the report will not describe themii. More information is available from Cichanowicz (1990); EPRI ( 1993):Frank and Hirano ( 1988):Haslbeck and others (1993); and Power Ma 'gtine (1990). The last in particular sumllmarizesthe technologies, developers, commercial status, and Linique fCatuLres. Examples. Two examples of SO0/NO, control processes in the early demonstration stage are shown in Figures 3.9 and 3.10,respectively. Performance. An NO, removal of 80 to 90 percent and a similar level of SO2 removal are expected fromiithese processes. The main advantages and disadvantages of six selected categories of combinhiedSO/NOy control processes are provided in Table 3.3 (Cichanowicz 1990). Postcombustion Technologies 37 Figure3.9 TheSOx/NOxProcess Dirtyfluegas Cleanftluetgaask p E c one ~Fluidized-bedi li | | t S~precipitator- :-.'.: ) I Tr ! I s -- - I Coalo Methane Ash NC recycle Figure3.9showstheSOx/NOxprocess.Sorbentis injectedintoanabsorber,whereit reactswith the S02 in the flue gas to form CaSO4and reducesthe NOxto elementalnitrogen. Sorbent regenerationandproductionof sulfur(througha Clausplant,bottomright)completetheprocess. Figure3.10 TheSOx-NOx-ROXBoxProcess Hotbaghouse bag Ammonia......filter_ ba coalAirr_ ~Y~~".surface SiSCRctls Drywastetodisposal Figure3.10illustratesthe SOx-NOx-ROXBox process. It is basedon a high-temperaturefabric filter(inthe"hot baghouse,"center),whichincludesanSCRcatalyst. Sorbentinjectionbeforethe baghouseremovestheS02, andammoniainjectionreducesNOxintonitrogen. 38 Clean Coal Technologies Table3.3 ComparisonofCombinedSO2/NOx ControlProcesses Process Advantages Disadvantages Adsorptlon/ High-temperaturegasisnotrequired Solidsrecirculationiscomplex regeneratlon Highremovalefficiency Highsorbentcosts Lowvolumeof wastes Highflue-gaspressureloss Potentiallymarketableby-product Fluegas Hightemperaturegasis notrequired Highauxiliarypower irradiationS02, NOX,andparticulateremovalin High-costreagent(ammonia) onedevice Plotential forsecondaryemissions(e.g.,N20) Potentiallymarketableby-product 13y-productdifficulttodisposeof Wetscrubbing Easilyretrofittabletoscrubbers Complexandpreciseprocesscontrolneeded additiveforNox OnevesselforSO2 andNOXremoval Wastescontainnitrogen/sulfurcompounds removalProcesschemistryalsosuitablefor Flue-gasreheatingmayberequired high-sulfurcoals Gas/solid Nosolidsrecirculation High-temperaturegasneeded catalytic HighSO, andNOxremoval Acidcollectionaddscomplexity operationsPotentiallymarketableby-product Catalystsmustbereplacedperiodically Electrochemical Mechanicallysimple Highauxiliarypowerrequired OnedevicetorbothSO-)andNOx High-temperaturegasrequired removal Noreagentsneeded Nohighvolumewastes Dryalkali High-temperaturegasnotrequired HighsimultaneousS02 andNO, removal Easilyretrofittabletodryscrubbers maynotbepossible Wastesdifficulttodisposeof Potentialforsecondaryemissions(e.g.,NO2) Source. Power Magazine (1990). Availability. The following points describe the commercial conditions under which combined SOJ/NOX control technology is available today. * Technology reacditness. Most of these processes are in the early development stage and are not expected to be commercially available before year 2000. * SSuppliers. See PovwerMAagaZine(1990). * Cost-effectivetie.s.s. Early projected capital costs range from US$300 to 400/ kW; the O&M costs range from 10 tol8 U.S. mills/kWh. The cost relative to that of other options cannot be assessed at this time because of the early developmental stage of these technologies. Suitability.The suitability and deploymient of the combined SO2/NOx control processes in developing countries should he assessed after they have been demonstrated and commercialized in industrialized countries (3 to 10 years, depending on the process). PostcombustionTechnologies 39 ParticulateRemovalTechnologies ElectrostaticPrecipitatorTechnologyEnhancements ESP is a well-known technology for controlling emissions of particulates. The purpose of this section is not to describe the conventional ESP technology, but to present a number of recent design and operating enhancements made to improve the efficiency and cost-effectiveness of ESP, as well as to give the basic information on availability, construction time, and so on. ESP performance improvements were made for a variety of reasons, including the following: * Tightening of regulations for particulate removal * Adverse impact of switching from one coal to another, or deteriorating coal quality, on ESP performance * Adverse impacts of upstream processes (e.g., sorbent injection), which affect the morphology and resistivity of the ash. ESPDesignand Operating Enhancements. Enhancements of ESP technology include the following: * Wide plate spacing, which reduces the specific collection area (SCA) and overall ESP costs while maintaining the collection efficiency by operating at higher voltages (sparking voltage level increases with wider plate spacing) * Intermittent energization, which improves performance and reduces auxiliary power requirements (small performance improvement, low-cost option) * Pulse power supply (moderate performance improvement, high-cost option) * Increasing ESP size (high performance improvement, high-cost option) * Flue-gas conditioning; both S03 and ammonia conditioning of the gas before entering the ESP are proven technologies that substantially improve the ESP performance * ESP automatic voltage controls and other energy management systems (high performance improvement and low cost). For more information see Chang and Altman (no date), EPRI (1994), and Offen and Altman (1991). Availability. The following points describe the commercial conditions under which electrostatic precipitator enhancement technology is available today. * Technology readiness. All the above ESP enhancements are commercially available. 40 CleanCoalTechnologies * Suppliers. Most suppliers of conventional ESPs offer the above options for new ESPs, as well as for retrofit applications. * Cost-effectiveness. Typical cost of a new ESP designed to remove 99.0 to 99.7 percent particulates (the U.S. standard) ranges from US$40 to 60/kW. Higher collection efficiency may increase the cost up to 100 US$/kW. The cost of the above ESP enhancements ranges from US$1 to 20/kW. The cost-effectiveness of each option is site-specific and depends on a number of factors, which include the performance and design specifications of existing ESP, ESP age and remaining life, required performance improvement (potentially required by new environmental regulations), and cost of power (U.S.mills/kWh). The flue-gas conditioning equipment costs do not necessarily increase with increasing unit size. That is, large units can be fairly inexpensive (US$1/kW) and small units very expensive. Total O&M costs of conventional ESPs range from US2 to 4 mills/kWh. Construction. ESP enhancements (with the exception of an ESP size increase) do not requiie more than 2 to 6 weeks of unit outage. Increasing the size of the ESP requires a 2 to 3 month outage. SuitabilityandDeployment.The ESP enhancements described in this section are suitable for developing countries but have not been widely used because particulate- related regulations are not as tight as they are in industrialized countries. If regulations are tightened and some clean coal technologies are used (especially spray dryers, sorbent injection, and fluidized-bed combustion) such ESP enhancements will be needed. If a market for such enhanced ESP features develops, supply should not be a problem. Fabric Filter(Baghouse) Technologies Bagfilters or baghouses are based on the following operating principle: particles and flue gas are separated in tube-shaped filter bags arranged in parallel flow paths. The particulates are collected either on the outside (dirty gas flow from outside-to-inside) or the inside (dirty gas flow from inside-to-outside)of the bag. Technology. The main differences among the various types of fabric filter technologies are related to the type of bag cleaning method. There are four general types of baghouses: reverse-gas, shaeke-deflate,pulse-jet, and sonic cleaning. These are described in Bustard and others (1988)and Carr and Smith (1984). Performance. Baghouses have been used in Canada, Europe, Japan, and the United States extensively during the last ten years because they are efficient at dust collection. Industrialized countries have started using bagfilters instead of ESPs because very often regulations require a collection efficiency above 99 percent, even for particles in the 0.05 to 1.0 micron range, which can be achieved more cost-effectively with bagfilters. PostcombustionTechnologies 41 Reverse gas-type baghouses are the most widely used, but they are expensive to build and operate. In addition to their large size, the pressure drop (and hence, the required auxiliary power) increases with time after each filter cleaning. Improved fabric materials and the addition of sonic cleaning improve the performance and cost- effectiveness of this technology. For more detailed descriptions of the recent advances in baghouse technology see Carr (1988);Chang and Altman (no date); Makansi (1986). Availability. The following points describe the commercial conditions under which baghouse technology is available today. * Technology readiness. Presently, more than 30 GW of baghouse capacity is installed in the United States and Canada. Baghouse technologies have been demonstrated adequately, and are commercially available throughout the world. However, they are not used widely in developing countries because of the high capital costs and, occasionally, because of the need to import the filter bag material. * Suppliers. A list of equipment suppliers is provided in Annex B, Table B6. * Cost-effectivenes.s. In general, ESPs are more competitive (lower capital and levelized costs) than baghouses for collection efficiency below 99.0 to 99.5 percent. In cases in which more than 99.5 percent collection efficiency is required, especially for low-sulfur coals, baghouses are more cost-effective. Typical costs for baghouses range from US$50 to 70/kW. Levelized costs are 3.5 to 4.5 mills/kWh for baghouses. Suitability.Baghouse technologies are suitable for developing countries. In particular, if developing countries use technologies such as spray dryers, sorbent injection, and atmospheric fluidized-bed combustion, baghouses will be required. Deployment.The key factors for useof baghouses in developing countries are the following: * Particulate emission requirements in developing countries favor ESPs, which are the most cost-effective systems for collection efficiencies of less than 99 percent. * The fabric bags may not be locally available and will need to be imported, requiring hard currency. * Power plant operating and maintenance personnel must be trained. Hot-GasCleanupTechnologies Hot-gas cleanup technologies are in anearly stage of development. Technology. Hot-gas cleanup (HGCU) technologies have emerged as key components of advanced power generation technologies such as pressurized fluidized-bed combustion (PFBC), and integrated gasification combined cycle (IGCC). The main difference between HGCUs and conventional particulate removal technologies (ESP and 42 CleanCoalTechnologies baghouses) is that HGCUs operate at higher temperatures (500 to 1,0000C) and pressures (10 to 20 bar), which eliminates the need for cooling of the gas. The most promising HGCU technologies are ceramic candle filters (see Figure 3.11), ceramic cross-flow filters, screenless granLIlar-bedfilters, acoustic agglomerators, and hot electrostatic precipitators. Figure3.11 Hot-GasCeramicCandle Filter Blowbackair reservoir |^* Gas outlet Tube sheet--m Prbessueet _ a i - d [ Filtercandles Pressure vessel Gas_ inlet Collecteddust * Ash to cooler and depressurizinglockhoppers Figure3.11showsa schematicof a hot-gasfilter. In theceramiccandle filter shown,gasflows fromthe outsideof thecandleinside(lowerleft). The particulatesare collectedontheoutsidesurfaceof thecandles,and the clean gas flows to the top of the pressure vessel and the stack throughthe gasoutlet(upperright). Periodiccleaningof thecandlesis donebyinjectingairfromtheblowbackairreservoir(top). PostcombustionTechnologies 43 Performance.The particulate removal requirements of HGCU systems are driven by particulate emissions standards and operating requirements to maintain reliable gas turbine operation. Additional design requirements include maximum volatile organic and alkali content at the HGCU outlet. Typical design requirements include greater than 99.9 percent removal efficiency of particulates larger than 10 microns. In some cases, similar removal efficiencies are required for particle sizes as low as 2 microns. Availability. The following points describe the commercial conditions under which hot-gas cleanup technology is available today. * Technology readiness. HGCU is in the early demonstration stage in industrialized countries. Of the above technologies, the more advanced are the ceramic candles and ceramic cross-flow filters (at pilot-scale demonstration). * Suppliers. The main developers of HGCU systems are Asahi Glass of Japan (ceramic candle filter), Combustion Power Co. of the United States (moving granular bed filter), Research Cottrell of the United States (hot ESP), Schumacher of Germany (ceramic candle filter), and Westinghouse Electric of the United States (ceramic cross-flow filter). * 'Cost-effectiveness. Because HGCU technologies are at an early development stage, an evaluation of cost-effectiveness is premature. In addition, HGCU technologies do not compete directly with conventional particulate removal technologies (ESPs and baghouses). Suitability. HGCU technologies are suitable for many of the coals found in developing countries. However, their applicability in developing countries is tied to the utilization of PFBC and IGCC technologies, which are still under development in industrialized countries. 4 AdvancedCoalUtilizationTechnologies Advanced coal utilization technologies include tluidized-bed combustion (both atmospheric and pressurized), which is generally ready for use in developing countries, as well as technologies still in high-cost or demonstration phases, such as integrated gasification combined cycle, and coproduction of electricity and clean fuels such as low- to medium-Btu gas and gasoline. In addition, this chapter discusses some advances in conventional pulverized-coal (PC) technologies that aim at enhancing cost effectiveness andefficiency. Fluidized-Bed Combustion Two basic types of fluidized-bed combustion are in operation-atmospheric fluidized-bed combustion (AFBC) and pressurized fluidized-bed combustion (PFBC). They are discussed below. AtmosphericFluidized-BedCombustion AFBC technologies are adaptable to both new and existing installations, work well in combination with other technologies, and are suitable for many local coals. However, their acceptance in many developing countries has been slowed by a lack of regulations requiring high removalof SO2. Technology.AFBC boilers differ from conventional pulverized-coal boilers in AFBC boiler/systems have the following processes and characteristics: * Limestone is injected into the furnace to capture the sulfur and remove it as a dry by-product. * Gas temperature in the boiler is 820 to 8400C ( 1,500 to 1,5500F), which affects the overall boiler design and the arrangement of heatingsurfaces. Figure 4.1 highlights the main differences between AFBC and PC boilers, as well as the two AFBC types: bubbling and circulating. A more detailed description of the AFBC process is provided in Tavoulareas (1991); Tavoulareas (1993); and EPRI and EMENA (1989). 45 46 CleanCoalTechnologies Figure4.1 DifferencesbetweenPulverizedCoaland AtmosphericFluidized-BedCombustionBoilers ( ~~__ 2000 / 1550~~~~~~~550 2500F Highgas Leangas! Cocurrent solids ratio / solids ratio flow cocurrent flow Rapid back-mixing I Pulverized coal AFBCbubblingbed AFBCcirculatingbed (PC) AFBC has * High heat transfer coefficient to furnace heat removal surfaces * High mass transfer rates for efficient S removal Figure4.1 shows howAFBCboilers (center and right)differfromconventional PC boilers (left). AFBCboilers operate at lower gas temperature, have high solids/gas ratio, high furnace heat transfer rates, and high mass transfer rates forefficientS02 removal. Source: EPRI and EMENA (1989), page I l. Performance. AFBC boilers can remove up to 90 to 95 percent S02, while generating 100 to 300 ppm NO, emissions. Bubbling AFBC Llsuallyremoves 70 to 90 percent of the SO, depending on the coal's characteristics and the amount of limestone added. Circulating AFBC can achieve 95 percent SO2) removal, with a calcium-to-sulfur (Ca/S) molar ratio of 1.5 to 2.0. NO, emissions can bc redLucedfurther (to 10 ppm) with the addition of selective noncatalytic reduction (SNCR) processes. Boiler and overall plant efficiency of both AFBC types are similar to those of conventional pulverized-coal plants. AFBC boilers are capable of burning low-quality coals (e.g., low-heating-value lignites, coal cleaning wastes, petroleum coke, and other waste materials). Also, the same boiler can accommodate a wider range of fuels than conventional pulverized-coal boilers. Because of the addition of limestone to the process. AFBC plants generate more solid wastes than conventional pulverized-coal plants. However, pulverized-coal plants with sorbent injection or spray dryers are expected to generate similar amounts of solid wastes, while wet scrubbers produce sludge, which is more difficult to handle and dispose of. In the United States, AFBC solid wastes have been classified as nonhazardous and therefore can be used for a number of applications (sub-base material for road construction, lightweight aggregate, cement production, and low-strength concrete materials). AdvancedCoalUtilizationTechnologies 47 AFBC technology is suitable for new power plants, retrofit (replacement of the existing boiler with an AFBC), and boiler conversion (replacement of part of the boiler with AFBC) applications. AFBC can also be combined with other technologies to meet the specific needs of each site. Of particular interest is the combination of coal cleaning, pulverized-coal, and AFBC technologies. Physical coal cleaning may be used to provide clean coal for a pulverized-coal plant, whereas the coal cleaning wastes and raw coal can be burned in the AFBC. The ability to burn the coal wastes in the AFBC introduces significant flexibility as to how the coal cleaning plant operates. It can be operated in such a way that it produces lower sulfur coal without regard to the generation of wastes with high thermal value. This concept is described in more detail by Miliaras (1991). Availability. The following points describe the commercial conditions under which atmospheric fluidized-bed combustion technology is available today. Technology readiness. AFBC technology has been demonstrated and is commercially available for modules up to 200 MW. More than 160 boilers (5.5 GW of installed capacity) are operating in North America, similar capacity is operating in Europe, andChina has more than 2,000 small bubbling AFBC boilers in operation. A number of projects are planned or presently implemented in the 250 to 350 MW size range. Electric Power Development Corporation of Japan has converted a 350 MW PC boiler at Takehara to a bubbling AFBC. EdF of France is building a 250 MW circulating AFBC (Lurgi technology), and a 250 MW project is under consideration for funding by the U.S. Department of Energy. In general, projects above 200 MW have higher technological risks, which must be addressed on a project-by-project basis. Because of the high S02 removal requirements in developed countries (usually above 90 percent removal), most of the recent projects utilize the circulating AFBC option. Bubbling AFBCs are not expected to be widely used in developed countries. * Suppliers. A list of suppliers is included in Annex B, Table B.7. * Cost-effectiveness. AFBC technology is 5 to 15 percent less expensive than a similar size pulverized-coal plant with dry or wet scrubbers (70 to 90 percent S02 removal). Projected capital costs for a 150 to 200 MW AFBC range from US$1300 to 1600/kW. AFBC technology is the technology of choice when fuel flexibility is desirable, low-quality fuels are available, low-NO, emissions are required, and high (70 to 90 percent) SO- removal is desired. Construction. Lead time is one year less than that for conventional PC because of the ability to utilize small, standardized modules (e.g.,90 or 150MW each). Suitability.AFBC technology is particularly adaptable for developing countries because it can burn the local coals (especially in China, India, Pakistan, and Eastern Europe). In addition, AFBC is similar in design, manufacturing, and operation to 48 Clean Coal Technologies pulverized-coal technology. Thus, it can be introduced and used by developing countries with minimal transition and effort. Although ci-culating AFBC is the preferred option in developed countries, developing couLntries may also choose bubbling AFBC technology, which provides adeqUate SO, removal (70 to 90 percent). is less expensive, and is simpler to operate. Deployment. The main barrier keeping AFBC from wide application in developing countries is the lack of high SO, removal reqLuirements. In developing countries, AFBC has to compete against conventional pulverized-coal plants, which have no SO, control technology. As SO, removal reClUirementsincr-ease to 60 to 90 percent, more and more AFBC boilers are likely to be used in developing countries. PressurizedFluidized-BedCombustionTechnology Four PFBC plants are operating in Europe, Japan, and the tJnited States. Technology. PFBC technology uses a combustion process similar to that of AFBC. but the boiler operates at higher than atmospheric pressure (5 to 20 bar), the gas is cleaned downstream trom the PFBC boiler, and the gas is expanded in a gas turbine (see Figure 4.2). More details of the PFBC process, and the design variations, are presented in Tavoulareas (1991). Performance.PFBC has the advantages ol AFBC technology (high SO2 removal, low-NO, emissions, ability to burn low-quality fLiels,and fuel flexibility) in addition to: * Compact design suitable for shop fabrication and modular construction * Easier retrofit than for AFBC into existing power plants, because of the limited space requirements * Potcntial lor achieving higher plant etficiency (up to 45 percent) than conventional pulverized coal or AFBC (36.5 percent) a Lower capital costs than IGCC or pulverized-coal with wet scrubbers. The demonstrated performance of PFBC technology is as follows: * More than 90 percent SO, removal, with a calcium-to-sulfur (Ca/S) molar ratio of 1.5 to 3.0 * NO, emissions at 100 to 200 ppm; NO, emissions can be reduced further with the utilization of selective noncatalytic reduction technologies * 40 to 42 percent efficiency in a combined cycle arrangement. Availability. The following points describe the commer-cial conditions under which pressurized fluidized-bed combustion technology is available today. * T>Technologyreadiness. PFBC technology is in the demonstration phase. Four PFBC plants are in operation (American Power Electric's Tidd in Ohio, ENDESA's Escatron in Spain, Stockholm Energi's Vartan plant, and EPDC's 70 MW Wakamatsu plant in Japan); all utilize PFBC modLIles of approximately 70 AdvancedCoalUtilizationTechnologies 49 MWe. One demonstration plant is in the design-construction phase: Kyushu Electric's 350 MW KI plant in Japan. The leading PFBC suppliers are willing to provide the technology, with commercial guarantees. However, a thorough risk assessment is recommended as specific design features may not be proven and might introduce increased risks. Areas that should receive particular attention are - Hot-gas cleanup technology; especially the demonstrated performance and reliability of the specific cleanup technology - Coal and sorbent preparation and feed systems - Effects of the PFBC boiler gas contaminants on gas turbine performance, reliability, and life expectancy. Sluppliers. The leading developer and supplier of PFBC technology is ABB Carbon, with a number of licensors, such as Babcock & Wilcox in the United States and Ishikawajima Heavy Industries (Ihl) in Japan. Other suppliers are Ahlstrom in Finland and Lurgi-Lentjes-Babcock in Germany. Figure4.2 PFBCCombinedCycle Technology Pressurized High-pressure fluidized-bed high-temperature combustion boiler gas cleanupsystem Cyclones (2 stages) Heat recovery . ] | i § ~~steam generatorl l l Combustion Conventional baghouse C)8 air ~~~~~~~~~~~or electrostatic precipitator Electric Air High-pressure generator compressor gas turbine Figure4.2showsa typicalpressurizedfluidized-bedcombustion(PFBC)combined-cycle system. Coal andsorbentare introducedat the bottomof the PFBCboiler(left),where the coal is burnedandthe sorbentreactswiththe S02 to form CaSO4. Cyclones(top center)or other hot-gascleanupdevicesremovethe particlesfromthe flue gas, which expandsina gasturbine(bottomcenter)andthen(centerright)passesthrougha heat recoverysteamgenerator(theturbineand steamgeneratorsconstitutethe "combined cycle"). Finally,thegasesaredirectedthrougha conventionalparticulateremovaldevice (ESPor baghouse)beforetheyreachthestack(right). 50 CleanCoalTechnologies Cost-effectiveness. Projections of capital costs for PFBC range from US$1200 to 1550/kW (equivalent to or up to 20 percent less expensive than pulverized-coal with wet scrubbers). However, PFBC has other advantages over pulverized-coal with scrubbers: fuel flexibility, modularity, and suitability for retrofit. Construction. Time for construction can be reduced by up to 2 years (relative to PC with scrubbers) using shop fabrication and modular construction. Therefore, a 70 MW PFBC plant can be built in 2 to 4 years. Suitability.PFBC technology is particularly suitable for most coals available in developing countries, but technology demonstration may be needed. Local manufacturing may not be feasible for the key components (boiler pressure vessel, hot- gas cleanup system, and gas turbine) because of the need for specialized equipment and highly trained personnel. As such, a larger percentage of the capital costs may be required in foreign currency (as compared to that for PC with scrubbers). Deployment. Some risks still remain associated with the performance of key PFBC components. Further demonstration of the performance, reliability, and cost- effectiveness of these technologies is needed in developed countries. Additional demonstration projects with different coals are needed in developingcountries. Coal GasificationTechnologies IntegratedGasificationCombined-Cycle Because of its high cost and early stage of development, IGCC technology is, for the near future, an unlikely choice of technology for developing countries with lenient S02 removal and NO, emission regulations. However, it is one of the few technologies (the other being PFBC) that significantly increases power plant efficiency and will have a beneficial effect in reducing emissions of CO,. As such, IGCC, like PFBC, is a technology that may be used in developing countries in the longterm. Technology.Coal gasification is a process that converts solid coal into a synthetic gas composed mainly of carbon monoxide and hydcrogen.Coal can be gasified in various ways by properly controlling the mix of coal, oxygen, and steam within the gasifier. There are also several options for controlling the flow of coal in the gasification section (e.g., fixed-bed, fluidized-bed, and entrained-flow systems; see Figure 4.3). Most gasification processes being demonstrated use oxygen as the oxidizing medium. IGCC, like PFBC, combines both steam and gas turbines ("combined cycle"). Depending on the level of integration of the various processes (see Figure 4.4), IGCC may achieve 40 to 42 percent efficiency. The fuel gas leaving the gasifier must be cleaned (to very high levels of removal efficiencies) of sulfur compounds and particulates. Cleanup occurs after the gas has been cooled, which reduces overall plant efficiency and increases capital costs (see Figure 4.4), or under high pressure and temperature (hot-gas cleanup), which has higher efficiency. However, hot-gas cleanup technologies are in the early demonstration stage. Advanced Coal UtilizationTechnologies 51 Figure4.3 GenericCoalGasificationReactors Fixed-bedprocess Fuidized-bedprocess Entrained-flowprocess (800-100lO',10-100bar) (800-1100-C, 10-25bar) (1500-1900'C,25-40bar) Coal(3-30mm) Gas Gas Gast V 5 I Coal t ~~~~~~Coal .1 (1-5mm)(.m)Ca Steam Steam Steam Steanm + S2m2 e+2 + +02 +0 +0 Ash Ash Slag urgi Lurgi KILnGAS KRW HT-Winider Krupp Texaco VEW DRY Slagger Koppora . PRENFLO __ _ Figure 4.3 showsthe main three coal gasificationprocesses: Left: fixed bed;center: fluidizedbed;andright: entrainedflow. Figure4.4 HighlyIntegratedGasificationPowerPlantConfiguration COAL CoalG n L preparation Gasificationva 02 N2 r AIR . .I.| ubn separation unit i Boilerfeed water(BFW) HFRESH Steam steam ConventionalintegratedGCC(_40%efficiency) - - - - - - -...AdditionforhighlyintegratedGCC(_42-45%efficiency) Sta Figure4.4 showsa typical IGCCprocess. Plantefficiencycan be improvedfurtherby injectingthenitrogenfrom theairseparationunit intothefuel gasbeforethe gasturbine andusingairfromthegasturbine/compressorintheairseparationunit(dottedlines). 52 Clean Coal Technologies After the fuel gas has been cleaned, it is burned and expands in a gas turbine. Steam is generated and superheated in both the gasifier and the heat recovery unit downstream from the gas turbine. The fuel gas is then directed through a steam turbine to produce electricity. Performance.IGCC plants can achieve up to 45 percent efficiency, greater than 99 percent SO, removal, and NO, below 50 ppm. Availability. The following points describe the commercial conditions under which integrated gasification combined-cycle technology is available today. Technology readiness. IGCC is in the demonstration phase. After the completion of the 100 MW IGCC demonstration at Cool Water, California, in the United States (5-year program completed in 1989), a number of other demonstration projects have entered the design or demonstration phase in Europe, Japan, and North America. Most of these projects use entrained gasifiers (e.g., Texaco, Dow, and Shell technologies). However, the U.S. Department of Energy's Clean Coal Technology Program has selected two projects (Siei-rraPacific's Pifion Project (80 MWe IGCC) using Kellogg technology, and the Tom Creek project (107 MWe IGCC) using the U-Gas technology developed by IGT), that are suitable for high- ash coals (such as those found in India and China). Also, a demonstration of Rheinbraun AG's HT Winkel fluidized-bed gasification process is planned in Europe. The results of these demonstration projects will be critical for assessing further the feasibility of these technologies for developing countries. * Suppliers. A list of IGCC suppliers is provided in Annex B, Table B.8. * Cost-effectivene.s. IGCC cost projections range from US$1500 to 1800/kW; 10 to 20 percent higher than for pulverized-coal with wet scrubbers. IGCC technology may be the technology of choice whenihigh SO2 removal (e.g., 99 percent or higher) and low-NO, emissions (below 100ppm) are required. Construction.Time for construction is expected to be similar to PC with wet FGD. However, phased construction (building of the gas turbine first, followed by the gasifier) can improve the economics of the IGCC plant by producing power as soon as the gas turbine is constructed. Suitability.IGCC technology is in the early demonstration phase and is more expensive than competing alternatives. Entrained IGCC technologies are suitable for low-ash coals. High-ash coals, such as those in India, would require fluidized-bed gasification processes. Deployment.The primary constraints to the application of gasification and IGCC plants in developing countries are that the technology needs further demonstration, the costs are higher than those of competing technologies, and the fact that environmental regulations in developing countries do not require the high SO2 removal and low-NO, emissions achieved by IGCC. AdvancedCoalUtilizationTechnologies 53 CoproductionofElectricityand Clean Fuels Because of the high cost of technology for the coproduction of electricity and clean fuels and its low cost-effectiveness at present price levels for coal and natural gas, it is currently not a sLitabletechnology choice for developing countries. Technology.Coproduction of electricity and clean fuels, such as methanol and gasoline, can be accomplished through the combination of coal gasification technology with other processes. Some potential applications, in addition to electricity generation, are as follows: * Production of medium-Btu gas for industrial users * Production of synthesis gas (hydrogen and carbon monoxide) for manufacturing of ammonia, methanol, and other chemicals * Production of gasoline and other distillate fuels. A generalized process flow diagram of coal gasification for coproduction of electricity and gas is shown in Figure 4.5. Figure4.5 GeneralizedFlowofCoalGasificationforProductionof FuelGas i COAL Air Water - - -- - - - - - - - - -, Flue gas fl r | ~~~~~~~~~~Superheated < 1 t ~~steam team _ separation 5Boiler mreheater Reheated 1t °2 water [ r C~~~ ~ ~~~~~lean: Coal Gasficatn,Aci gas ue gas handling gas cooling,removal & SCrubn Condensate Acid gas Plant power _ . requirements Cooling wasewatera Sulfura tower treatment recovery Ash Sulfur ELECTRIC CLEAN POWER FUELGAS The systemshownin Figure4.5differsfromthatshownin Figure4.4 inthat it usesonly part of the fuel gas generatedby the coal gasificationprocessto produceelectricity;the restmay be processedfurtherto producegasolineanddistillatefuelsor usedasit is bytheprocessindustry. 54 Clean Coal Technologies The gas produced by a plant with a flow such as that shown in Figure 4.5 could be processed further to produce gasoline and distillate fuels. Similar arrangements are needed to produce synthesis gas. Availability. The following points describe the present state of commercial development for coproduction technology. * Technology readiness. A number of alternative technologies have been demonstrated, but are not fully commercialized. * Cost-effectiveness. Coproduction processes using coal gasification are not cost- effective at present fuel prices (oil below US$20/barrel and natural gas below US$4/MBtu). Most technologies are expected to become cost-effective when oil prices exceed the US$40 to 50/barrel level. Suitability.These coproduction technologies are not considered suitable for developing countries because they are in the early stages of development and their costs are high relative to those of conventional power generation methods. AdvancesinPulverized-CoalOutputand Efficiency To present a balanced picture of the coal-fired power generation and environmental control technologies, it is essential to mention developments in conventional pulverized-coal technology, which is used widely throughout the world. Whereas the clean coal technologies described in chapters 2 and 3 are developments directed at improving the environmental performance of pulverized-coal technology, other developments are enhancing its cost-effectiveness and overall efficiency. These include technological advances in designl, contr-ol, and fault diagnosis, cutting-edge advances in thermodynamic efficiency, and wider applications of advanced plant rehabilitation and life-extension methods. The purpose of this section is not to provide a complete review of these aspects but to raise the level of awareness about advances that need to be taken into account in comparing coal-fired technologies. More detailed assessment of pulverized-coal technology, as it pertains to utilization in developing countries, is needed. Technology Advances Significant improvements have been made in three main technical areas: improvements of the power plant design, instr-unmentation,and maintetnance. Design. The following improvements in the design of power plants are noteworthy for application indeveloping countries. * Dynamic pulverizer classifiers for improved coal fineness and better combustion efficiency * New types of air heaters (e.g.,plate-type and heat pipe) AdvancedCoalUtilizationTechnologies 55 * Corrosion-resistant alloys or coatings (e.g., Cr-9 and 3.5 NiCrMoV steels), which make power plants more reliable InstrumentationandControls.Advanceshere includethe following: * Performance monitoring and optimization systems * Digital controls * Instrumentation for coal flow and size distribution measurement, acoustic pyrometry for furnace temperature measurements, unburned carbon loss monitoring and on-line coal quality monitoring * Continuous emission monitoring equipment (especially for CO, 02, CO2, and NOx). PredictiveandPreventiveMaintenance.Systematic maintenance techniquesare used widely in industrialized countries to minimize forced outages and maximize power plant output. With the rapidly increasing power and decreasing costs of personal computers, a variety of software has been developed and made available to the power industry at affordable cost. A number of technologies have been developed also to provide early diagnosis of equipment deterioration and prediction of remaining life (next failure). Diagnostic monitoring equipment for rotating machinery (pulverizers, turbines, fans, and pumps) and pressure part components (e.g., boiler tubes) are commercially available and can assist the power plant operator in predicting when these components will fail and in taking preventive measures to avoid unit forced outages. ThermodynamicCycle Improvements.Recent thermodynamic cycle improvements include the utilization of supercritical, double-reheat steam cycles and once-through/variable pressure boilers with spiral-wound waterwalls, which have raised the plant efficiency to the 41 to 43 percent level (based on low heating value). Also, research has been initiated in many industrialized countries (Europe, Japan, and the United States) to integrate pulverized-coal technology with gas turbines into combined cycles with higher overall plant efficiency. However. the11'efforts are still in the pilot- stage and are not considered suitable for developing couniiii. LifeExtensionlRehabilitation Use of diagnostic monitoring equipment for power plant life extension (rehabilitation) is, very often, the most cost-effective option available. Power plant reliability and, therefore, unit output (MW), decrease with time, even in well-maintained units. According to EPRI (no date-b), availability may drop from nearly 80 percent at the 20th year of operation to about 50 percent after the 30thyear, to less than 30 percent after the 40th year. Poor maintenance accelerates the decline in reliability and output. Moreover, as one would expect, the expenses of refurbishment increase as the system output and availiability decline. On the other hand, an effective enhanced maintenance program can keep system availability at 80 percent or better over the life of the plant. 56 Clean Coal Technologies Life extension/rehabilitation methods have advanced significantly during the last two decades. Such methods apply to all critical power plant components (pulverizers, boiler, turbines, and balance-of-plant equipment) and include replacement of parts (e.g., air heater baskets and boiler economizer section) or whole components (e.g., replacement of low-pressure steam turbine), coatings with new materials (e.g., erosion-resistant coatings of boiler tubes), and installation of additional components (e.g., dynamic classifiers on the pulverizers). Steam turbine and generator manufacturers have confirmed that considerable design margin exists in old (pre-1965) turbines, which can be refurbished to increase output with relatively small cost (Miliaras 1991). This output increase can be accomplished with design improvements such as * Enhancement in steam admission and flow-path design geometry * Replacement of several rows of last-stage blades with those of a more advanced design (before the early 1960s,blades were designed using two-dimensional flow theory; now, more advanced flow analysis has improved blade designs). * Improved generator insulation * Advanced controls. TechnologyReadiness Most technologies mentioned above are commercially available in industrialized countries and are highly suitable for developing countries. However, a lack of awareness about these technologies, as well as lack of incentives to improve power plant performance and methods to evaluate and plan life extension/rehabilitation projects, limit their utilization in developing countries. Recommendation Assessment of the status and suitability of the power plant life extension and rehabilitation technologies for developing countries is needed. It should include * Status of the key technologies * Suitability for developing countries and selection of the most suitable technologies * Information on commercial availability * Guidelines on how developing countries should evaluate and utilize key technologies * Case studies (examples from specific power plants in developing countries). 5 Relationshipbetween EnvironmentalRegulations and TechnologyChoice As described in chapters 2 to 4, each clean coal technology is capable of achieving a different level of emission reduction at a different cost level; or, for a given emission level required by environmental regulations, one or more technologies may satisfy the emission criterion in a cost-effective manner. Therefore, technology choice is closely tied to environmental requirements. The link between required removal of SO2 and most cost-effective technology choice is summarized in Table 5.1 The most cost- effective processes for required levles of NO, removal are shown in Table 5.2 Table5.1 MostCost-EffectiveProcessesforSO2 Removal Required SO2 removal (%) Most cost-effectiveprocesses < 30 Coal cleaning (depending on coal characteristics) 30 to 70 Dry sorbent injection (furnace sorbent injection, duct injection, dry scrubbers [FGD]) 70 to 90 Atmospheric fluidized-bed combustion and dry scrubbers (FGD) 80 to 95 Atmospheric and pressurized fluidized-bed combustion and wet scrubbers (FGD) >95 Integrated gasification combinedcycle, wet scrubbers and pressurized fluidized-bed combustion Note: FGD= flue-gasdesulfurization. Table 5.1 indicates that for each level of S02 removal, different technologies should be selected as more cost-effective. 57 58 CleanCoalTechnologies Table5.2 MostCost-EffectiveProcessesforNOxRemoval Required NOr reduction (%) Most cost-efective processes 30 to 60 Low-NO, burners with or without overfire air are the most cost- effective. Similar NO, reduction can be achieved with selective noncatalytic reduction and reburning, but these technologies are more expensive than low-NO, burners. 50 to 70 Low-NO, burners with reburning or SNCR are the most suitable technologies. 70 to 90 Selective catalytic reduction is the technology of choice. Note: SNCR= selectivenoncatalyticreduction. Because each technology has a different level of emissions (e.g., SO2, NO,, CO2 , particulates, solid wastes), statements regarding its attractiveness ("this is the technology of choice") should be accompanied by the main environmental requirements (e.g., SO2 removal, NO, emissions, particulate removal). Sample environmental regulations of different countries are provided in Annex A. 6 Suitabilityof Clean Coal Technologies: A ScreeningMethod The most suitable technologies for each developing country and each project are unique. To identify the technology best suited for a particular situation, a number of criteria must be considered. This brief chapter lists some criteria for evaluating the suitability of CCTs and provides a general rating of the main technologies in tabular form. EvaluationCriteria The primary criteria for evaluation are listed below: * Technology readiness e Suitability for the characteristics of the coal to be used i Suitability for environmental requirements (SO2 removal, NO, emissions, particulate removal, solid waste generation and disposal, and plant efficiency) *Desirability of modular construction * Capital and O&M costs * Applicability to existing and new power plants * Capability of indigenous personnel to specify, procure, design, manufacture, and operate the plant * Impact on foreign exchange requirements. A technology evaluation begins by checking and clarifying the criteria listed above. The next step is to identify all the relevant power generation and environmental control technologies. Finally, one can move on to evaluate each technology relative to the criteria and select the most appropriate technologies. These steps are discussed in detail below: * Readiness. The technology should be commercially available in industrialized countries; at least 3 to 5 utility scale facilities (100 MWe or larger) should be in operation, demonstrating the successful implementation of the technology. 59 60 CleanCoalTechnologies 0 Suitability. The technology should be suitable for the characteristics of the coal(s). Minor adaptation of the technology to the unique characteristics of certain coals would not be perceived as a major disadvantage. However, if major design changes are required, this would not reflect favorably on the technology. * Perfonmance. Parameters include SO2 removal efficiency, NO, generation, particulate emissions, solid waste generation, and plant efficiency (heat rate or CO2 emissions). * Modularity. Most developing countries will prefer prefabricated, easy-to-install modules, usually up to 100to 200 MW each. * Costs. Both capital and O&M (operating and maintenance) costs must be considered. * Applicability. This indicates whether the technology is suitable for new power plants or retrofit applications. Considering that life extension and rehabilitation of existing power systems is of primary importance, in developing countries, technologies that are applicable for both new plants and retrofits would receive higher ratings. e InJigenous capability. This relates to the ability to train local personnel easily in the process and power plant design, to develop the necessary manufacturing capability, and to be able to operate and maintain the facility. * Foreignl excliange imipact. This relates to the foreign exchange requirements for technology acquisition, training, and purchasing of power plant components that cannot be manufactured in developing countries. (Note: a high rating means a small impact on foreign exchange requirements.) The total rating reflects the cumulative score of all criteria considered and is accompanied by an indication of the applicability ot a technology for short- or long-term applications. The total rating can be developed either by comparing the ratings of the technologies relative to each criterion or by assigning a weighting factor to each of the ratings (e.g., I for low, 2 tor medium,and 3 for high). Relevant Technologies Table 6.1 summarizes the ratings of the technologies described in chapters 2 to 4. It should be noted that the rating, according to the above criteria, and the selection of the most promising technologies are to illustrate the methodology. The results are not applicable to all countries. However, they are based on realistic requirements and could be applicable to most developing countries. Use of the word Ion¢g-terinmeans that the technology is either in the early stages of development in industrialized countries or needs extensive adaptation to the unique requirements of developing countries, which usually takes more than three to five years. It does not mean, however, that there is nothing to be done in the near future. Table 6.1 Clean Coal Technologies for Developing Countries Indigenous Planl Applicabilit _ capability O&M Foreign capa- exchange Total Readi- Suit- Reductioniof Solid effic- Modu- Capital O&M New Existing Process inmpactrating Termn Technology niess abiliht S02 NOQ PM waste iencv larity costs costs units units atnddesign Mfg. bility 0 a 0 0 0 S Physical coal cleaning * Y *na 0 0 0 0 0 0 Y 0 S Low-NO, burners 0 S n.a. * 0 n.a. 0 n.a. Y Y Y 0 0 0 0 S Sorbent injection 0 0 0 n.a. n.a. 0 n.a. n.a. 0 Y Y 0 0 0 0 0 S Duct injection 0 S O n.a. n.a. 0 n.a. n.a. * 0 Y 0 0 Y Y 0 0 0 0 0 sv Dry scrubber 0 0 * n a. nia. 0 n.a. 0 Y 0 0 0 0 0 L Wet scrubber * 0 * n.a. n.a. 0 0 0 0 i y _. 0 0 Y Y 0 0 0 0 0 L SNCR 0 0 n.a. 0 n a. n.a. 0 n.a. Y Y 0 0 0 0 0 L SCR 0 O n.a. * n.a. n.a 0 0 0 0 0 0 0 0 0 L DeSOX/DeNOx 0 - * 0 n.a. - - - 0 0 Y Y CD Y 0 0 a 0 0 S AdvancedESP * S n.a. n.a. 0 0 n.a. * * * Y 0 Y Y 0 0 0 0 0 S Bag filter * S n.a. n.a. 0 0 n.a. 0 0 Y N 0 0 0 0 0 L Hot-gasclean-up 0 - n.a. n.a. 0 n.a. n.a. S 0 0 Y Y 0 0 0 0 0 S Bubbling AFBC * * * * n.a. 00 0 N 0 0 0 0 0 S o Circulating AFBC S * * * n.a. 0 0 S 0 0 Y 0 Y Y 0 0 0 0 0 L cQ PFBC 0O * * n.a. OS * 0 0 0 0 0 0 L Entrained IGCC 0 ea * *S 0*0 0 0 0 Y N 0 0 0 0 0 L > Fluidized bed IGCC 0 *b55 * 0*0 0 0 0 Y N * 0 * 0 0 S Large subcriticalPC * S n.a. n.a. n.a. n.a. 0 0 0 0 Y N CD 0 0 0 0 0 L Large supercritical PC * * n.a. n.a. n.a n.a. 0 0 0 0 Y N 0 0 0 0 0 S Plant life extension * * n.a n.a. n.a n.a. * n.a. * * N Y n.a. = Not applicable L = long Y yes * High rating (good performance, low cost, good capability, low impact -= Data not available PM = particulate matter S = short N = no on foreign exchange) Mfg.= manufacturing C 0 Medium rating 0 Low rating a For high-heating-value coals only. bFor lignites and high-ash coals only. 7 Conclusionsand Recommendations Many clean coal technologies are available or in development, including coal cleaning; improved or new methods for coal combustion; environmental control technologies (add-ons to existing plants); and advanced methods for using coal in environmentally cleaner ways (fluidized-bed combustion, gasification, and coal-derived clean fuels). These technologies have been developed primarily in industrialized countries, although some have been demonstrated adequately in the industrialized countries and can be considered as available for use in developing countries. Ultimately, the choice of a particular technology for a specific country must take into account the close relationship between a proven technology and that country's environmental needs and regulations. TechnologyChoicesforDevelopingCountries Considering the environmental regulations of most developing countries, the state of development of clean coal technologies, the limited financial resources available in developing countries, and other factors, it is worth summarizing the technologies that have been identified as suitable for short- and long-term applications in developing countries. TechnologiesforShort-TermApplications Technologies suitable for the short term include the following: * Conventional physical coal cleaning * Low-NO, combustion technologies * Sorbent and duct injection * Dry scrubbers * Circulating AFBC * Advanced electrostatic precipitator technologies 63 64 CleanCoalTechnologies * Bagfilters (only when sorbent/duct injection and AFBC technologies are also introduced) * Large subcritical pulverized-coal and life extension/rehabilitation technologies. Technologies for Long-TermApplications Technologies suitable for application in the long term includethe following: * Pressurized fluidized-bed combustion (PFBC) * Large supercritical pulverized coal * Wet scrubbers (flue-gas desulfurization). This selection is generic and may not be applicable to all developing countries. Country-specific assessments are recommended to identify the most suitable technologies and the specific actions to be undertaken. AdditionalRecommendationsforDevelopingCountries The following additional recommendations are offered on appropriate clean coal technologies for developing countries: Plhysical coal cleaninlg technologies ave casilY adaptable for use in developing couiintries anld clre cost-effective ie i)iost cases. Coal cleaning reduces transportation costs, sulfur and particulate emissions, and improves power plant reliability. Developing countries are urged to adopt coal pricing policies that reflect the quality of the coal and its impacts on power production costs and emission generation. - Low-NO, burners shloluldbe inclucded in the designi specifications of all future povter plants and prOvisions shold be aladefor overfire air ports. Such specifications will not increase the power plant costs by more than US$5 per kW, but they will result in significant savings when future environmental regulations requir-c further NO, reductions. * Efficienit operation ol power plants, especiallY whleniNO, emissions nmuestbe mniniuized, is aIsimportant as in.stall(ationof low-NOr burnier.v. Therefore, power plant operators must be trained and supplied with the appropriate power plant instrumentation, controls, and optimization software needed to keep NO, emissions low. * Dry scrubbers and sorbent injection techInologies offer anlattractive alternative to dh'velopinig colltries ithrougl ithI/ichlmoderate sWhril removal cani be achlieved at '- relatively lowl cost. However, further- demonstration of most sorbent-based technologies will be required in developing couintries. ConclusionsandRecommendations 65 Electrostatic precipitator technology has uindergone significant advances and should be introduced more vigorously into developing couintries. This technology also has a short payback period (I to 5 years). Bagfilters may be required in developing countries, especially if technologies such as sorbent injection, dry scrubbers, and fluidized-bed combustion are used. Atmosphericfluidized-bed combutstion technology, especially the circulating tvpe, is particularly suitable for developing countr-ies. Use of this technology should be promoted. Recommendations forthe World Bank To promote the use of environmentally benign technologies without encouraging developing countries to select high-risk/high-cost technologies, the following actions are suggested: * Develop a set of criteria that mnustbe m1etby each technology before it canlqlualify for use in developing countries. One criterion, for example, could require that the technology have been used in at least five to ten power plants of 100 MW or larger in industrialized countries, and that it has performed well and reliably. Another criterion would require that the technology have demonstrated good performance with a coal similar to the coal to be used for projects in developing countries. * Performiia technology risk assessment thzatidentifies the risks associated with the technology and proposes a risk managemlenit plan. Such an assessment should identify all the risks, as well as their source, and provide ways to minimize them or manage them. For example, in some cases, the technology developers would be willing to accept the technology-related risks through equity-participation or special guarantee arrangements. * Initiate a study to assess the cost-effectiveness of power plant life extension/rehabilitationi techlnologies. This would be a prelude for identifying the most suitable technologies for developing countries, and developing guidelines on how to screen and select the best options. Annex A Sample EnvironmentalRegulationsin Selected Countries 67 68 Clean Coal Technologies TableA.1 StandardsofAmbientAirQualityand EmissionsinAsianCountries (Unit: mg/m3, unless otherwise indicated) Pollutant Counitry Annual average 24-hour maximum Daily average S02 China 0.06 0.50 0.15 India Indonesia 0.26(0. 1ppm) Philippines 0.85 (0.3ppm)a 0.37 (0.14ppm) Thailand 0.10 0.30 (Reference) World Bank 0.10 0.5 (Outside) I.0(inside) USA 0.06(0.02ppm)b 0.26 (0.lppm)b 0.08 (0.03ppm)C 0.365 (0.14ppm)c 1.3 (0 5ppm)td FRG 0. 14 (0.05ppm) 0.40 (0.14ppm) Japan 0.26 0.11 ((. 04ppm) NOx China 0.15 0.1 India Indonesia 0.093 (0.05ppm) Philippines 0.19 (0. lppm)a Thailand 0 32 . a (Reference) World Bank 0.1 (0.O5ppm) USA 0.1 (0.O5ppm) FRG 0.1 (0.O5ppm) 0.30 (0.15ppm) Japan 0.04-0.06 Dust China 1.0ie 0 30e 0 0.50f 0. I ff India In(donesia 0.26 Philippines 0 2 5a 0.15 Thailand 0.10 0.33 (Reference) WVolid Bank 0.10 0.50 USA 0065b 0,15b 0.075c 0.26c FRG 0 1 0.29 (-)1h 0,4h Japan 0.20 0.1 Source: Kataoka1993). " I-hr axerage. h Secondarv-based on environrncrtal efiects. c Primary-based on health cl'fcctson humans. d max 3-hr-once yearly. CTot;;lsuspend. tFlv dust. S50 MW)Coal-FiredBoilers (Unit: mg/Nm3) Countr/regionSuispendted par!iczulates Nitrogenioxides Suljir oxides Australia 80 500;a 2.000 800 (>30 MW)b Austria 50 200 (>300 MW); 200 250 (>300 MW FBC boilers); 300 (150-300 MW); 400 (50-150 MW) Belgium 50 650 (>300 MW); 200 (>300 MW);d 400 (50-300 MW)c 400 (>300 MW);e 1,200(100-300 MW); 2,000 (50-100 MW) Bulgaria 650 Canada 125(43 g/GJ) 740(258 g/GJ) 715 (250 g/GJ) China 200;6400:f60 Calculated according to the formula q=Px 10-6xHe2 where P is a factor specified by regulation to various regions and He equals stack height.9 Czech Republic 100 650 500(>300 MW); 1.700(50-300 MW) Denmark 50 200 400 (>500 MW); 2.000-400(101-499 MW, sliding scale); 2,000 (<100 MW) European 50 (>500 MW); 650; 400 (>500 MW); Union 100 (<100 MW) 1,3 h 2,000-400 (101-499 MW, sliding scale); 0 0 2,000 (<100 MW)i Finland 60(20 g/GJ) 135(>300MW), (50 380 (>150 MW); (140 g/GJ); gI/GJ): 620 (50-150 MW); (230 g/GJ) 405 (50-300 MW)(I50 glGJ) France 50 (>500 MW); 650 (>50 MW): 400 (>500 MW);k 100(<500 MW) 1,300(>50 MW)j 800 (400-500 MW);1 2,400-4xMW (100-500 MW)m Germanyn 50 200 (>300 MW); 400 (>300 MW) and 85% sulfur removal; 400 (50-300 MW) 2,000(100-300 MW) and 60% sulfur removal; 2,000 (50-100 MW) Indiao I50(>210 MW);9 350 (<210 MW) IndonesiaP 400-600 170-460 570-866q ltalv 50 200 (>500 MW); 400 (>500 MW); 300 (300-500 MW utility 800 (>400 MW); FBC boilers); 1,600-400 (200-500 MW, sliding scale); 650-200 (300-500 MW, 2,000-1,600 (100-200 MW, sliding sliding scale); scale); 650(50-300 MW) 2.000(50- 100 MW) Con2tinueson next page 70 Clean Coal Technologies Table A.2 (continzued) CountrY/region Suspendedr!paricidiaes Nitrogei oxides Sulfur oxides Japan 50 (>200,000 410 (>700,000Nm3/hr Set individually according to the formula Nm3/ hr gas gas emission), (200 K x 10-3 x He2 = (m3/h) emission); ppm); K = areaconstant; He = stack height (m). 100(40,000- 510 (40,000-700,000 Range: 170-860 (60-300 ppm) 200,000 Nm3/hr Nm3/hr gas emission),'r gas emission); (250 ppm); 150 (<40,000 720 (<40,000Nm3/hr gas Nm3/hr gas emnission),(350 ppm) emission) Koreas 250 875,(350 ppm) 2,200, (700 ppm) Netherlands 50 200 (>300 MW); 200 (>300 MW) and 90% sulfur removal t (<300 MW) by FGD; 5 00 700 (<300MW) New Zealandu 125;V250W 410, (200 ppm) 125 Philippinesx 150;Y2OOz 1,000;(350 g/GJ) 1,500;(573 ppm) Poland 190-600; 100-490, 540-1,760, (70-1,370 (35-170 g/GJ)bb (200-650 g/GJ)CC gIGJ)aa Romania 400 (>500 MW); 2,000-400 (100-500 MW, sliding scale); 2,000 (50-100 MW) Spain 50 (>50()MW); 650; ,1 3 0 0dd 400 (>500 MW); 100 (50-500 2,000-400 (101-499 MW, sliding scale); MW) _ 2.000(50-100 MW)ee Sweden 50 X0(>300 MW); 160(>500 MW); (30 g/GJ); (30 g/GJ); 135(<300 MW): 270 (<500 MW); (50 g/GJ)ff (50 g/GJ) Switzerland 50 200 (>300 MW); 400 (>100 MW) and 85% sulfur removal; 400 (50-300 MW) 400 (<100 MW)99 Taiwan 2 5 50 0 - hh 720-1.025; 1,430-3.145; (350-5(N ppm) (500-1.400 ppm)i Thailandii 400 940.(500 ppm) 1,.300,(500 ppm) Turkey I5(kk 800) 400 (<300 MW FBC boiler): I.801ll 1.)000(>300 MW); 2,000 (<300 fixed bed boiler) Uniited 5(t(>500 MW); 650 400 (>500 NIW); Kinldonimm 100 (50-1 00 2'.000-4(MW-100) (100-500 MW); MW) 2.000(50-(100MW)nn United States 60; 615-740; 1,480(>73 MW), (0.05 lb/MBtu) (0.5-).6 lb/NlBtu.and (1.2 lb/MBtu)PP 65% removal)oO Con tiniies oninext page Annex A: Sample Environmental Regulations 71 Table A.2 (continueld) Unitsof imeasure: MW = megawatt;mg/Nm3 = milligrams per normal cubic meter; g/GJ = grams per Gigajoule; lb/MBtu = pounds per million British thermal unit; ppm = parts per million parts of flue gas. Coniversionifactors: I mg/Nm3 = 2.86 g/GJ; I mg/Nm3 = 1,230 lb/MBtu; I mg/Nm3 NOX= 2.05 ppm NOx; I mg/Nm3 S02 = 2.86 ppm SOx. Note: Table A.2 was compiled by Ms. Magda Lovei, World Bank Environment Department. Source: Except as otherwise indicated, the source for suspended particulates and NO, standards is Soud (1991) and that for SO2 standards is International Energy Association (1993). a. Applicable to industrial plants. b. Applicable to utility plants. c. Standards applicable to plants built after December 31, 1995: * 200 mg/Nm3 (>100 MW) * 400 mg/Nm3 (50-100 MW). d. Post-1995 standard, applicable to plants for which first application for authorization was submitted after June 3, 1987. e. Pre-1995 standard, applicable to plants for which first application for authorization wassubmitted before June 3, 1987. f. Applicable to Class 1-111areas, respectively (Resourcesfor the Future, 1992): - Class 1: nature reserves, scenic spots, places of historic interest - Class 11:urban areas, suburbs, industrial areas e Class 111:other places. g. Dingrong (no date). h. Applicable to fuels with less than 10percent volatile compounds. i. For combustion plants firing indigenous high- or variable-sulfur coal, the following standards apply: * 90 percent removal (>500 MW) * 60 percent removal (<300 MW) * 40-90 percent removal sliding scale (167-499 MW) * 40 percent removal (100-166 MW). j. Applicable to fuels with less than 10percent volatile compounds. k. Plants that, because of special characteristics of the coal, cannot meet the set standards must achieve 90 percent sulfur removal. 1. Applicable to plants with less than 2,200hours/year operating time. m. Plants that use domestic coal and, becauseof special characteristics of the coal, cannot meet the set standards should achieve * 40 percent sulfur removal (100<167 MW) and * (0.15 MW+ 15)percent sulfurremoval (167·500 MW). n. International Energy Agency (1992). o. Government ol India(1986). p. Budihardjo (1993). q. In SO3. r. Applies where construction started after April 1, 1987. International Energy Agency (1992). s. Moon (1993). t. For PF boilers licensed after 1993,applicable standard is 100mg/m3. u. International Energ! Agency (1992). v. Applicable to large emitters. Continues on next page. 72 Clean Coal Technologies Table A.2 (continued) w. Applicable to small and medium emitters. x. Philippines Department of Natural Resources (1993). y. Applicable to urban and industrial areas. z. Applicable to other areas. aa. Lowest standard applicable to PF wet bottom boilers firing lignite, highest to stationary stroker boilers firing hard coal. bb. Depending on coal type and removal technology. cc. Depending on coal quality and furnace type. dd. Applicable to fuelswith less than 10percent volatile compounds ee. Additional standards: * utility plants firing indigenous coal: 60 percent sulfur removal * utility plants firing imported coal: 800 mg/Nm3 * plants firing indigenous high or variable sulfur coal: 60 percent sulfur removal. tf. Additional guidelines: * combustion plants emitting more than 300 t NOx per year: 135-270 mg/m3 (100-200 g/GJ) * combustion plants emitting less than 300 t NOx per year: 270-540 mg/m3 (100-200 g/GJ). gg. Additional requirements lor FBC boilersunder 100MW: 75 percent sulfurremoval. hh. Lihits depend on quantity of flue gas emitted and location of power plant. 11.Additional standards tor * utility plants: 1,430-2,145 mg/m3 (500-750 ppm) * imported coal fired plants: 3,145mg/mi3 (1,I00 ppm) * domestic coal fir-edplants:4,000 mg/hn3(1,400 ppm). jj. Source: Chiewwattakee, 1993. kk. Limit can bedoubled by governmientpermission for lignite-burning facilities. International Energy Agency (1992). 11.For units using pulverized coal. International Energy Agency (1992). mm. Her Majesty's Inspectorate of Pollution (1991). nn. Additional standards tor combustion plants firing indigenous high or variable sulfurcoal: * 9)0percent sulfur removal (>500 MW) * 4)0+ 0.15 (ME-166) percent sulfur removal (155-500 MW) * 4)0percent sultur removal (100-166 MW) * 2.250 mng/n3(50-100 MW individualboilers and furnaces). OO.Depending on mine location and furnace type. pp. Additionally, maximum achievable limits: * greaterthan 90 percent sultur removal: 1,480mg/NnO(1.2 Ib/MBtu) * ninety percent sultur removal: 740-1,480 mg/Nm3 (0.6-1.2 lb/MBtu) * between 70 and 90 percent sulfur removal: 740 mg/m3 (0.6 lb/MBtu). Annex B EquipmentSuppliers 73 74 CleanCoalTechnologies A general reference to U.S. suppliers is provided in the "93/94 Buyers' Guide Issue to Power Plant Products and Services," in Power Enginieering, September 1993. TableB.1 SuppliersofCoal CleaningTechnologies Headquarters Contact Telephone Fax Supplier namtie (couintry) Address person nzwnber nlumnber Notes AO Energomachexport Germany Allen and Garcia Co. United States Daniels Co. United States Envirotech Coal United States Services Corp. Hey] & Petterson. Inc United States Lively Mfg & United States Equipment Co. McNally Pittsburgh. Inc. United Stales Roberts & Schaeffer United States Corp. Warman International United States Inc. Note: Suppliers from other countries were not readily availahle at the time of preparation of this report. Countries such as Germany, United Kingdom and Australia have organizations providing coal cleaning technologies throughout the world. TableB.2 SuppliersofLow-NOxCombustionTechnologies Ileodquorurt.s Coltact Telephone [(Ia Sup phier,bamn e (coo 1 ir) Add(rtess pecrsoni nzumber numtplber Notes Babcock Energy UniLcd Kingdom International I l.ited Combustion lItd Kinedom Burmaister & Wain Germ;anv Steiinmuller Gcrmiany Mitsuhishi JLpan Hfea) lndustries Bahcock-Ililtachi Japan ABB/CE UJnitedStates Windsor. CT or Chattanooga. TN Babcock & Wilcox United States Barberton, Oli Corp Foster Wheeler Corp. lnited Stales Livingston. NJ Phconix Corp United Statcs Riley Stoker UniLcdStatcs Boston. MA Pillard Francc 13 Rue Raymond NMr.MIaurice (33) 91 8() (33) 91 Teissere Idoux. 90 21 25 72 13272 NMarseille Export Manager 71 Cedex 1)8 Annex B: Equipment Suppliers 75 TableB.3 SuppliersofSorbentand DuctInjection Processes Headquartcrs Cotztact Telephone Fax Supplier name (counitry) Address person niunmber number Notes Babcock & Wilcox United States CONSOL Inc. United States (Coolside process) Dravo Corp. (HALT United States process) BechtelCorp.a United States Lurgi Corp. Germany Wulff GmbH (Reflux CFB) Tampella Corp. of Finland Finland (LIFAC) Airpol Inc. (AIRPOL) United States Damp (ADVACATE) United States a Markets the Confined Zone Dispersion (CZD) process. 76 Clean Coal Technologies Table B.4 Suppliersof Wet and DryFGD Processes Headquazrters Comtact Telephzone Fax Supplier niamne (countwi) Address person number numbzer Notes ABB Environmental United States Windsor. CT Systems Air Products Inc. United States Allentown. PA Airpol, Inc. UniLed States General Electric United States Schenectady, NY Environmental Syslems Joy Environmental United Slates Teehnologies NaTec Resources, Inc. United States Research Cottrell United States Atlanta. GA WheelabraLor Air Ulnited States Pollution ConLrol Chiyoda Corp. Japan Flakt Denmiark Lurgi Corp. Germainy Tampella Power Corp. Finlaind CNIMa France 35 Rue De Bassano Mr. Guy ChanLV. (33 1)44 (33 1) 75008 Paris Export Manager 31 II 00 47 23 09 2(0 LAB SA France Tour Credit Lonnrais (33) 78 63 (33) 78 129 Rue Servienl 7090 60)94 69431 Lyon Cedex (03 87 Procedair France 25-27 Boulevard De La (33 1) 39 (33 1) Paix 73 92 15 39 73 78100 St-Gernmain En 09 17 Lave Genevetb France 37 BI\NdMalesherhes Nr. Michel (33 1)42 (33 I) 750)08 P)aris Comte, 65 91 72 42 65 Export Manager 63 04 INORb France 8 Rue Ilenri Becquerel (33 I) 47 (33 1 92508 Rucil 1t()(3 50 47 32 Malmaison Cedex 04 54 GEC Alsthom Group France 38 Avetrue Kleher (33 1)47 (33 1) Boilers & 75795 Paris Cedex 16 55 2(0 00 47 55 En%ironmental Systerms 21 1) Division a Postcombustion flue-eas cleanirin (semi-wet limest(ne injection process lor SO- neutralization). b Posteombustion advanced flue-gas cleaning Annex B: Equipment Suppliers 77 TableB.5 SuppliersofSCRSystems Headquarters Contact Telephlone Fax Supplier name (couIntry) Address personz numtber nunber Notes ABB United States Babcock & Wilcox United States Cormetech. Inc. United States Engelhard Corp. United States Joy Environmental United States Systems Norton Co. United States Riley and Rhoen- United States Poulenc Inc. Siemcns Germany GEC Alsthom Group France 38 Avenue Kleber (33 1) 47 (33 1) Boilers & 75795 Paris Cedex 16 55 20 00 47 55 Environmcntal Systems 21 10 Division 78 Clean Coal Technologies Table B.6 Suppliersof Bagfilters Headquarters Conltact Telephone Fax Supplier name (counitry) Address person niuimiber inuember Notes ABB Environmental UnitedStates Systems Airpol, Inc. UnitedStates Babcock& Wilcox UnitedStates Corp. ElectricPower UnitedStates Menlo Park.CA Technologies Fishcr-KlostcrmanInc. UnitedStates Flex-KlccnCorp. UnitedStates FullerCo. UnitedStates HoffmanAir & UnitedStates FilLrationSystems. Division of Clarkson Industries.Inc. Joy Environmental UnitedStates Technologies ResearchCottrell UnitedStates Atlanta,GA SouthernResearch UnitedStates Birmingham.AL Institute WheelabratorAir UnitedStatcs PollutionControl Zurn Air Systems UniLedStates Flakt.Environmental Denmark Systems DeutscheBabcockAG Germany Annex B:Equipment Suppliers 79 TableB.7 SuppliersofAFBCBoilers Headquarters Contact Telephone Fax Supplier name (country) Address person number nunber Notes Ahistrom Finland Pyropower United States Foster Wheeler United States Lurgi Corp. Germany ABB/Combustion United States Engineering Stein Industries France B.P. 74 Mr. Jacques (33 1) 34 (33 1) 78141 Velizy Barthelemy, 65 45 45 34 65 Villacoublay Cedex Export Director 43 99 Gotaverken and Sweden Studsvik Tainpella Power Corp. Finland Babcock & Wilcox United States Combustion Power United States Corp. Energy Products of United States Idaho KCeelcr/Dorr-Oliver United States Deutsche Babcock Germany Werke TableB.8 Suppliersof IGCCProcesses Headquarters Conteact Teleplione Far Supplier name (countrv) Address person number number Notes Dow Chemical United States GEC Alsthom Group France 38 Avenue Kleber (33 1)47 (33 1) Boilers & 75795 Paris Cedex 16 55 2000 47 55 Environmental Systems 2110 Division M.W.Kellogg United States Shell (USA) United States T1'\u.I,"United States o (iilss United States 'IcI hii .loty (IGT) Notes: European suppliers: British Gas, Lurgi, Shell and RheinbraunAG (HTWinkel fluidized-bed gasification process). Japanese suppliers: Mitsubishi is developing a air-blown entrained gasification process. References Budihardjo, Sayid, R.M. 1993. "Integrating Improved Coal Technologies into the Energy System." Paper presented at IEA Second International Conference on The Clean and Efficient Use of Coal and Lignite: Its Role in Energy, Environment and Life. Bangkok, 30 November - 3 December. Bustard, C. J., and others. 1988. "Fabric Filters for the Electric Utility Industry." EPRI publication CS-5161; vol. 1: General Concepts;vol. 2: Sonic Cleaning Guidelines. Caniada Gazette. 1990. Thermal Power Generation Emissions National Guidelines for New Stationary Sources. Part I. Carr, R. C., and W. B. Smith. 1984. "Fabric Filter Technology for Utility Coal-Fired Power Plants." EPRI publication CS-3724-SR, October. Chang, R., and R. Altman. No date. "Advances in Particulate Control Technology." EPRI. Chiewwattakee, Atthaya. 1993. "Reducing Environmental Impact From Using Coal and Lignite in Thailand." Paper presented at IEA Second International Conference on The Clean Efficient Use of Coal and Lignite: Its Role in Energy, Environment and Life. Bangkok, 30 November - 3 December. Cichanowicz, E. 1990. "Engineering Evaluation of Combined NO,/SO2 Technologies." EPRI Jounzal, pp. 4-7. Claussen, R. L., and others. 1993. "Engineering and Design Guidelines for Duct Injection Retrofits." Paper presented at the SO2 Control Symposium, Boston, Massachusetts, August 24-27. DePero, M. J., and others. 1993. "Final Results of the DOE LIMB and Coolside Demonstration Projects." Paper presented at the 2nd Annual Clean Coal Technology Conference, Atlanta, Georgia, September 7-9. Dingrong, Zheng. "A Study of the World Bank Environmental Guidelines and an Appraisal of Coal Fired Plant in the People's Republic of China." Draft. Dooley, B., and R. Viswanathan. No date. "Life Extension and Assessment of Fossil Power Plants." EPRI publicationCS-5208. Palo Alto, California,United States. Epperly, W. R., and J. E. Hoffman. 1989. "Control of Ammonia and Carbon Monoxide Emissions in SNCR Technologies." Paper presented at the AlChE Conference, August 20-23. EPRI (Electric Power Research Institute). 1983. "Coal Gasification Systems: A Guide to Status, Applications, and Economics." EPRI publication AP-3109, June. 1985. "The Value of a Power Plant's Remaining Life: A Case Study with Baltimore Gas & Electric Co." EPRI publication EA-4347, November. Palo Alto, California, United States. 81 82 Clean Coal Technologies . 1986. "Generic Guidelines of Life Extension of Fossil Fuel Power Plants." EPRI publication CS-4778. Palo Alto,California, United States. November. . 1993. Proceedings of the S02 Control Symnposiutn(Section 5A). Boston, Massachusetts, August 24-27. Available from EPRI (also availablefrom U.S. EPA and U.S. DOE). Palo Alto, California, United States. 1994. "Meeting the Particulate Control Challenge: State-of-the-Art Tools for Controlling Particulate Emissions from Fossil-Fired Power Plants." . No date-a. "Economic Evaluation of Plant-upgrading Investments." Palo Alto, California, United States. EPRI publication EA-3890. _.___ No date-b. Strategy for Fossil Plant Life Extension at Boston Edison Co.'s Mystic Unit * #6." EPRI publication CS-4779. EPRI and EMENA (World Bank Europe, Middle East, and North Africa Vice-Presidency). 1989. ThzeCurrenitState oJAtmnosplhericFluidized-Bed Comlbustion7echinology. World Bank Technical Paper 107. Washington, D. C. Eskinazi, D. 1993. "Retrofit NO, Controls for Coal-Fired Utility Boilers." E.PRIpublication TR-1(02071,Summer. Palo Alto,California, UnitedStates (licensed material). European Community. 1988. Council Directive 88/609 of 24 November on the limitation of emission of certain pollutants into the air from large combustion plants, O.J. L 336/1. Published in the European Community Deskbook. 1992. The Environmental Law Institute, Washington D).C. Exxon Research & Engineering. 1989. "Thermal DeNO, Process." April. Frank, N. W., and S. Hirano. 1988. "Combined NO,/SO-) Removal by Electron-Beam Processing." Paper presented at the 4th Symposium on Integrated Environmental Control, Cosponsored by EPRI, Air Pollution Association and the American Society of Mechanical Engincers. Washington, D.C..March 2-4. Government of India. 1986. "Environment (Protection) Rules." Schedule 1. In Gazette of India: Extraordinarv . Haslbeck, J. L., and others. 1993. "NOXSOCombined NO,/SO, Flue Gas Treatment Process- Proof of Concept." Paper presented at the SO2 Control Symposium (Section 5A), Boston, Massachusetts, August 24-27. Available from EPRI, U.S. EPA, and U.S. DOE. Washington, D.C. Her Majesty's Inspectorateof Pollution). 1991. Clhief Inspector's Guidance to Inspectors. Environmental Protection Act 1990 Proccss Guidance Note IPR I/I. Combustion Processes Large Boilers and Furnaces 50 MW(th) and Over. London: HMSO. International Energy Agency. 1990. NOr Control Technologies for Coal Com7bustion. International Energy Agency Coal Research, London. 1992.Coal Informliationt1992. International Energy Agency. 1993.FGD PovwerPlanits. International Energy Agency Coal Research, London. References 83 Japan Electric Power Information Center, Inc. 1992. Thermal Power and Environmental Pollution Control in Japan. Jechoutek, Karl G., and others. 1992.Steam Coalfor Power and Industry: Issues and Scenarios. Energy Series Paper 58. World Bank, Industry and Energy Department. World Bank, Washington D.C. Kataoka, S. 1993. "Coal Burning Plant and Emission Control Technologies." Paper presented at the 2nd Annual Clean Coal Technology Conference, Atlanta, Georgia, September. 7-9. Keen, R. T., and others. 1993. "Enhancing the Use of Coal by Gas Rebuming and Sorbent Injection." Paper presented at the 2nd Annual Clean Coal Technology Conference, Atlanta, Georgia, September 7-9. Makanski, Jason. 1990. "Will Combined SO2/NO, Processes Find a Niche in the Market?" PowerMagazine (September):26-28. Miliaras, S. 1991. "Clean Coal Technologies for Developing Countries." Preliminary draft for United Nations Energy Resources Branch, September. Moon, Hee Sung. 1993. "Integrating Coal Use into Korean Energy Systems." Paper presented at IEA Second International Conference on The Clean Efficient Use of Coal and Lignite: Its Role in Energy, Environment and Life. Bangkok, 30 November - 3 December. Offen, G., and R. Altman. 1991. "Issues and Trends in Electrostatic Precipitation Technology for U.S. Utilities," Journal of theAir and Waste Management Association 42(2). Philippines Department of Environment and Natural Resources. 1993. Administrative Order. No. 14.Manila. Podolski, W. F., and others. No date. "PFBC Technology." Noyes Data Press. RFF (Resources for the Future). 1992. Handbook of Regulations on Environmental Protection in China. Original Compiled in Chinese by the Beijing Municipal Environmental Protection Bureau. Soud, Hermine N. 1991. Emission Standards Handbook:Air Pollutant Standardsfor Coal-fired Plants. IEACR/43 International Energy Agency Coal Research, London. Tavoulareas, S. 1991. "Fluidized-Bed Combustion Technology." Annual Review of Energy (October): 25-27. 1993. "Clean Power Technology Menu for India." Report prepared for U.S.AID, August 27. Williford, C. W. 1989. "Review of Coal Pretreatment Methods for Enhancement of Coal Liquefaction." EPRI preliminary draft paper, December 29. Distributors of World Bank Publications KENYA SINGAPORE, TAIWAN, ARGENTINA The Middle East Observer Africa BookService(E.A.)Ltd. NtYANMARBRUNEI CarlosHirsch.SRL 41,Sherif Street Street Cow,er Asia Pacific Pte Ltd. Galena Guemes Cairo Quaran House. Mfangano Golden Wheel Building Flonda 165.4th Floor-Ofc. 453/465 P.O. Box45245 41,Kallang Pudding, t04-03 1333BuenosAires FINLAND Nairobi Akateemnnen Kir,akauppa Smgapore 13334 Oficina del Ulbro Internacional P.O. Box 128 KOREA, REPUBLIC OF SOUTH AFRICA, BOTSWANA Albern 40 SF-00101HeLsinki 10 PanKorea BookCorporation For,iigle hitles: 1082BuenosAires P.O. Box 101,Kwangwhamun FRANCE Seoul C,ford University Press Southern Africa AUSTRALIA, PAPUA NEW GUINEA, World Bank Publications P 0. 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