Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP Environmental, Health, and Safety Guidelines Pulp and Paper Mills specific variables, such as host country context, assimilative Introduction capacity of th e environment, and other project factors, are The Environmental, Health, and Safety (EHS) Guidelines are taken into account. The applicability of specific technical technical reference documents with general and industry- recommendations should be based on the professional opinion specific examples of Good International Industry Practice of qualified and experienced persons. When host country (GIIP) 1. When one or more members of the World Bank Group regulations differ from the levels and measures presented in are involved in a project, these EHS Guidelines are applied as the EHS Guidelines, projects are expected to achieve required by their respective policies and standards. These whichever is more stringent. If less stringent levels or measures industry sector EHS guidelines are designed to be used than those provided in these EHS Guidelines are appropriate, together with the General EHS Guidelines document, which in view of specific project circumstances, a full and detailed provides guidance to users on common EHS issues potentially justification for any proposed alternatives is needed as part of applicable to all industry sectors. For complex projects, use of the site-specific environmental assessment. This justification multiple industry-sector guidelines may be necessary. A should demonstrate that the choice for any alternate complete list of industry-sector guidelines can be found at: performance levels is protective of human health and the www.ifc.org/ifcext/enviro.nsf/Content/EnvironmentalGuidelines environment. The EHS Guidelines contain the performance levels and Applicability measures that are generally considered to be achievable in new The EHS Guideline for Pulp and Paper Mills includes facilities by existing technology at reasonable costs. Application information relevant to pulp and paper manufacturing facilities of the EHS Guidelines to existing facilities may involve the including wood-based chemical and mechanical pulping, establishment of site-specific targets, with an appropriate recycled fiber pulping, and pulping based on non-wood raw timetable for achieving them. materials such as bagasse, straw, and reed. It does not include production or collection of raw materials which are addressed in The applicability of the EHS Guidelines should be tailored to other relevant EHS Guidelines. Annex A contains a description the hazards and risks established for each project on the basis of industry sector activities. of the results of an environmental assessment in which site- This document is organized according to the following sections: 1 Defined as the exercise of professional skill, diligence, prudence and foresight Section 1.0 — Industry-Specific Impacts and Management that would be reasonably expected from skilled and experienced professionals engaged in the same type of undertaking under the same or similar Section 2.0 — Performance Indicators and Monitoring circumstances globally. The circumstances that skilled and experienced Section 3.0 — References and Additional Sources professionals may find when evaluating the range of pollution prevention and Annex A — General Description of Industry Activities control techniques available to a project may include, but are not limited to, Annex B — Effluents and Emissions Guidelines / Resource Use varying levels of environmental degradation and environmental assimilative capacity as well as varying levels of financial and technical feasibility. Benchmarks DECEMBER 10, 2007 1 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP dibenzodioxins) and PCDF (poly chlorinated dibenzofurans), 1.0 Industry-Specific Impacts commonly referred to as chlorinated dioxins and furans. When and Management Elemental Chlorine Free (ECF) or Total Chlorine Free (TCF) The following section provides a summary of EHS issues bleaching technologies are used, the concentrations of dioxins associated with pulp and paper mills, which generally occur and furans in the effluents are below the detection limits. 3 . during the operational phase, along with recommendations for their management. Recommendations for the management of Among the sources of nitrogen and phosphorus compounds EHS issues common to most large industrial facilities during the released into wastewaters, and potentially contributing to construction, operation and decommissioning phases are eutrophication of receiving waters, is the wood raw material provided in the General EHS Guidelines. which is also a source of resin acids. Resin acids, especially those based on coniferous wood pulp, can be toxic to fish and 1.1 Environment benthic invertebrates. Chlorinated phenols can be produced by The more significant environmental aspects of pulp and paper elemental chlorine based bleaching of pulp. mills during the operational phase relate to: Other issues related to wastewater discharges may include fish • Wastewater tainting, color related to COD content and discharges of black • Air emissions liquor, pulp spills from overflowing tanks, and runoff from log • Waste yards. This last source may contain toxic chemicals (such as • Noise tannins, phenols, resins, and fatty acids) leached from the timber, and soil and other materials washed out of the bark. Wastewater Wastewater Management – General Pulp and paper manufacturing activities may generate Information about water conservation strategies applicable to wastewater discharges at a rate of 10-250 cubic meters per most industrial facilities, which may contribute to the reduction of metric ton (m3/t) of product. Product is measured as air dry wastewater streams, is provided in the General EHS pulp (ADP 2) in pulp mills, and as weight of paper sold in paper Guidelines. Industry-specific wastewater prevention strategies and board mills. Prior to treatment pulp mill effluents are high in potentially applicable to most pulp and paper manufacturing total suspended solids (TSS; mainly from cooking and pulping processes are presented below. Recommended wastewater process screening, washing, and bleaching stages as well as prevention and control methods include the following: from debarking residue, chemical recovery inorganics and fillers); biochemical oxygen demand (BOD) chemical oxygen demand (COD) and dissolved organic compounds mainly 3 Of the chemicals listed in Annex C of the Stockholm Convention, only PCDD and PCDF have been identified as being produced during the production of pulp arising from wet debarking cooking/pulping, screening, washing, using elemental chlorine. Of the 17 PCDD/PCDF congeners with chlorine in the 2,3,7 and 8 positions, only two congeners – namely 2,3,7,8-TCDD and 2,3,7,8- bleaching, and chemical recovery plant liquor spills). Bleach TCDF – have been identified as potentially being produced during chemical pulp bleaching using chlorine. Most of the formation of the 2,3,7,8-TCDD and 2,3,7,8- plant effluents may include PCDD (poly chlorinated TCDF is generated in the C-stage of bleaching via the reaction of chlorine with precursors of TCDD and TCDF (UNEP, 2006). 2 Air dry pulp refers to pulp that is 90% dry. DECEMBER 10, 2007 2 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP • Dry debarking of wood; o Reducing application of elemental chlorine by • Systems for collection and recycling of temporary and decreasing chlorine multiple or increasing the accidental discharges from process water spills; substitution of chlorine dioxide for molecular chlorine • Sufficient and balanced volumes of pulp storage, broke o Minimizing precursors such as dibenzo-p-dioxin and storage and white water storage tanks to avoid or reduce dibenzofuran entering the bleach plant by using process water discharges; precursor-free additives and thorough washing; • Recycling of wastewater, with or without simultaneous o Maximize knot removal recovery of fibers (using filters or flotation plants); o Eliminating pulping of furnish contaminated with • Separation of contaminated and non- contaminated (clean) polychlorinated phenols wastewaters with collection and reuse of clean non-contact • Removal of hexenuronic acids by mild hydrolysis for cooling waters and sealing waters; hardwood pulp, especially eucalyptus; • Potentially contaminated stormwater includes runoff from • Collection and recycling of spent cooking liquor spills; log and wood handling areas, process equipment, building • Stripping and reuse of evaporation and digester roofs and areas immediately around the mill process areas. condensates in order to reduce odor producing total This should be combined with process effluent for reduced sulfur (TRS) compounds (Kraft and sulfite mills). treatment. • Neutralization of spent cooking liquor before evaporation and reuse of condensate in order to reduce dissolved Guidance applicable to the management of cooling water, and organics (Sulfite mills); additional guidance applicable to stormwater, is presented in the • Including chemical recovery in sulfite as well as Kraft mills. General EHS Guidelines. Wastewater Management – Kraft and Sulfite Pulp Mills Wastewater Management – Mechanical and Chemi- mechanical Mills Additional recommended wastewater prevention and control Additional recommended wastewater prevention and control methods for Kraft and sulfite mills include the following: methods for mechanical and chemi-mechanical mills include the • Oxygen delignification ahead of the bleach plant; following: • Efficient washing of the pulp ahead of the bleaching (Kraft • Minimizing reject losses; and sulfite mills); • Maximizing water recirculation in mechanical pulping • Decreasing or eliminating the formation of 2,3,7,8-TCDD process; and 2,3,7,8-TCDF in wood and non-wood bleaching • Application of thickeners to effectively separate water processes by 4: systems from the pulp and paper mills; o Replacement of elemental chlorine bleaching with elemental chlorine free (ECF) bleaching 5 or total chlorine free (TCF) bleaching 5ECF bleaching requires on-site manufacture of chlorine dioxide (ClO2). The ClO2 process chosen should have low production of chlorine as a by -product of 4 UNEP, 2006. ClO2 production. DECEMBER 10, 2007 3 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP • Separation of pulp mill and paper mill water systems as Generic wastewater treatment technologies are discussed in the well as use of counter-current water system from paper to General EHS Guideline. Specific recommended applications pulp mill to reduce overall water consumption, TSS and common in the paper and pulp industry are as follows: dissolved organics. • Primary mechanical treatment: A mechanical clarification basin or settling pond is commonly used to remove Wastewater Management – Paper and Integrated Mills suspended solids from wastewater. Chemical flocculation Additional recommended wastewater prevention and control to assist in the removal of suspended solids is sometimes methods for paper and integrated mills include the following: applied; • Recycling of white water, with fiber recovery by means of • Secondary treatment: Biological treatment is applied in disc filters, drum filters or micro flotation units and most types of pulp and paper operations with relatively high minimization of the number of fresh water intake points to discharges of organic pollutants, including toxic the white water system; compounds such as resin acids and chlorinated organics. • Separate treatment of coating wastewaters, e.g. by ultra Specific applications include a number of different types filtration – recycling of coating chemicals; and configurations of biological treatment. The most • Substituting potentially harmful process chemicals with less commonly used systems include a combination of i) harmful alternatives. activated sludge; ii) aerated lagoons; iii) biological filters of various types, often used in combination with other Wastewater Treatment methods; iv) anaerobic treatment used as a pre-treatment End of pipe wastewater treatment technologies will depend on stage, followed by an aerobic biological stage; and v) several factors including effluent composition, measurable combinations of different methods, when very high effluent quality requirements, and discharge location (e.g. direct efficiencies are necessary; to water course or pre-treatment before discharge to municipal • Additionally, extended aeration time is sometimes required or other WWTP). Pulp mill wastewater treatment should to oxidize toxic compounds such as resin and fatty acids, typically include primary treatment consisting of neutralization, reduce biological sludge formation and to help ensure screening, sedimentation (or occasionally floatation/ consistently high levels of treatment; hydrocycloning) to remove suspended solids, • Anaerobic biological pretreatment is favored for certain biological/secondary treatment to reduce the organic content in types of effluents that are high in BOD/COD and low in wastewater and destroy toxic organics, and, less frequently, toxic substances, such as sulfite pulping condensates and tertiary treatment to further reduce toxicity, suspended solids, mechanical pulping and RCF effluents, with reuse of the organics, and color. Wastewater treatment processes generate remaining purified condensates to reduce overall water sludge which requires management as a waste material or as consumption and effluent volumes. by-products. DECEMBER 10, 2007 4 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP Air Emissions TRS gases. The recovery boiler is the preferred point of The principal air emissions in pulp and paper production consist incineration; of process gases which vary by type of pulping process and • As far as possible, the point of discharge of the necessary which may include sulfur compounds (with associated odor emergency vents to atmosphere should be a high, hot issues), particulate matter, nitrogen oxides, volatile organic stack, such as the recovery or power boiler. compounds, chlorine, carbon dioxide, and methane. Other • When waste water treatment plant odors are problematic, common sources of emissions include flue gases from considering use of oxygen activated sludge with capture incineration plants and from auxiliary steam and power and subsequent incineration of gaseous emi ssions. generating units emitting particulate matter, sulfur compounds Incineration of the TRS gases can be accomplished within the and nitrogen oxides. process equipment, preferably in the recovery boiler where Process Gases – Kraft and Sulfite Mills sulfur can be recovered, but also in the power boiler. For Malodorous Gases (Kraft mills) - Kraft pulping processes concentrated gases, other options include the lime kiln (although typically emit highly malodorous reduced sulfur compounds the resulting generation of calcium sulfate needs to be denoted as total reduced sulfur (TRS), which include hydrogen considered), or in a separate external incinerator. sulfide, methyl mercaptan, dimethyl sulfide, and dimethyl Recovery Boilers (Kraft and sulfite mills) – Emissions from disulfide. Wastewater treatment plants can sometimes be a recovery boilers are typically characterized by the presence of more significant source of malodorous gases that the process particulate matter and sulfur dioxide. Other key constituents itself. Recommended emissions management strategies include nitrogen oxides and sometimes hydrogen sulfide in kraft include the following: mills. Sulfur dioxide recovery is considered fundamental in • For bleached and unbleached Kraft mills, malodorous sulfi te mills. Primary emissions management strategies include gases from vents at all points in the process handling black the following: liquor, unwashed brown pulp, partially washed brown pulp, • Oxidation of black liquor prior to direct contact unbleached pulp, and condensates should be collected and evaporation 6; incinerated to completely oxidize all reduced sulfur • Reducing sulfur emissions by concentrating black liquor in compounds; the evaporator (Kraft mills) above 75% dry solids before • In the case of high concentration gases (generally from incineration in the recovery boiler; condensates and digester vents), a stand-by system for • Reducing sulfur emissions by controlling combustion incineration should be provided, designed to take over from process parameters in the recovery boiler including the main system, as required, thus minimizing venting of temperature, air supply, distribution of black liquor in the TRS gases to the atmosphere; furnace, and furnace load (Kraft mills); • In sensitive situations (i.e. proximity to residential areas), consideration should be given to a standby incinerator or 6Applicable to existing facilities, as direct contact evaporators should not be other alternative incineration point for the low-concentration used in new facilities. DECEMBER 10, 2007 5 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP • Reduced emissions of nitrogen oxides (NOx ) by control of • Use of secondary particulate emissions controls such as firing conditions, such as excess air; electrostatic precipitators in recovery boilers, auxiliary • Collecting SO2 emissions by absorption in alkaline solution boilers, and lime kilns; to generate new cooking liquor (sulfite pulp mills) • Use of secondary SO2 emissions controls such as alkaline wet scrubbers for removal of acid gases and by-products of Stacks should be designed according to the Good International the incineration of TRS gases. Industry Practice (GIIP) approach provided in the General EHS Guidelines.7 Volatile Organic Compounds (All mills) 8 - Volatile organic compounds (VOCs) are emitted to the atmosphere from poorly Lime Kilns (Kraft mills) – The calcination reaction process designed utility boilers burning bark and other wood-based fuel. results in emissions of NOx , SO2, and particulate matter. TRS At mechanical pulping mills, principal sources of VOC emissions gases may also be released due to poor removal of sodium include evacuation of air from wood-chip washing and from the sulfide (Na2S) from the lime mud. Recommended primary condensing shower, where steam released in mechanical emissions management strategies include the following: pulping processes, contaminated with volatile wood • SO2 emissions should be reduced through use of low sulfur components, is condensed. The concentrations of VOCs content fuel and control of excess oxygen; depend on the resin content of the wood and the specific • NOx emissions should be reduced through control of firing defiberizing techniques applied. The emitted substances include conditions; acetic acids, formic acids, ethanol, pinenes, and terpenes. • Hydrogen sulfide emissions should be reduced by proper Recommended measures to minimize VOC emissions include: kiln operation and control of residual sodium sulfide in the • Ensure that VOC emissions from mechanical pulping of lime mud. This can be achieved by proper lime mud wood with high extractive (resin) content are recovered in washing and filtering to remove sodium sulfide and the heat recovery units and the start- up scrubber (for TMP decrease water content (to about 20 to 30 percent) which steam), and collect and further treat volatile compounds. permits on- filter air oxidation of residual sulfide prior to the VOC-containing exhaust air can be incinerated in existing dried mud entering the kiln. boilers or a separate furnace. Terpenes can be recovered Recommended secondary emissions control measures from those contaminated condensates that contain mainly applicable to the above sources of emissions include the terpenes; following: • Operating bark boilers with excess oxygen sufficient to prevent VOC (and CO) emissions while minimizing formation of NOx . Fluidized bed technology is preferred for solid waste boilers. 7 For pulp mills, this may consist of a high single stack typically over 100 meters in height above immediately surrounding land or as defined by atmospheric 8 This section addresses VOCs other than the malodorous compounds emissions dispersion modeling. discussed above. DECEMBER 10, 2007 6 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP Combustion Sources efficient vacuum pumps; and proper sizing of pipes, pumps Pulp and paper mills are large energy and steam consumers and fans; sometimes making use of auxiliary boilers (bark boilers and • Maximizing the generation of electric power by maintaining additional steam boilers) for the generation of steam energy. high boiler pressure; keeping outlet steam pressure in the Emissions related to the operation of these steam energy back-pressure turbine as low as technically feasible; using sources typically consists of combustion by-products such as a condensing turbine for power production from excess NOx , SOx , PM , and volatile organic compounds (VOCs), and steam and maintaining high turbine efficiency; and greenhouse gases. Recommended management strategies preheating of air and fuel charged to boilers. include adoption of a combined strategy which includes a reduction in energy demand, use of cleaner fuels, and Guidance for the management of small combustion source emissions with a heat input capacity of up to 50 MWth, including application of emissions controls where required. In energy exhaust emission guidelines, is provided in the General EHS efficient non-integrated pulp mills, the heat generated from black Guidelines. Guidance applicable to combustion sources greater liquor and bark combustion should exceed the energy than 50 MWth is presented in the Thermal Power Guidelines. requirement for the entire production process. Recommendations on energy efficiency are addressed in the Residues and Waste General EHS Guidelines. Additional recommendations specific Pulp and paper mills typically generate significant quantities of to pulp and paper operations include: 9, 10 non-hazardous solid wastes but very little hazardous wastes. Industry specific wastes include bark from debarking of wood, • Reducing heat losses and heat consumption by increasing residual pith from bagasse pulping, inorganic sludge (e.g. green dry solids content of bark which is burnt; increasing liquor sludge, lime sludge) from chemical recovery, trash (e.g. efficiency of steam boilers (e.g. use of economizers); plastics) separated from paper/card in RCF plants, and fiber increasing effectiveness of the secondary heating system (i.e., primary clarifier) sludge and biological sludge from (e.g. hot water about 85 °C); increasing use of secondary wastewater treatment. A small amount of hazardous waste is heat to heat buildings; and increasing high pulp generated in all mills, and includes oil and grease residues, concentration, as well as maintaining a tightly closed water scrap electrical equipment, and chemical residues which system and a partially closed bleaching plant; normally amount to about 0.5-1kg/ton of product. • Reducing electric power consumption by maintaining as high a pulp consistency as possible in screening and The classification of solid wastes as hazardous or non- cleaning; controlling the speed of large motors rather than hazardous should be established based on local regulatory using throttling valves or dampers for flow control; using criteria. Hazardous and non-hazardous wastes should be carefully segregated to reduce the volume of wastes that could be contaminated with hazardous material and hence classified as hazardous. Guidance for management and safe disposal of 9 EU BREF (2001). 10 See also Williamson (1994) for additional guidance on energy efficiency hazardous and non-hazardous industrial waste is addressed in improvements. DECEMBER 10, 2007 7 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP the General EHS Guidelines. Additional guidance specifically dewatering or, less frequently, as forest fertilizer applicable to pulp and paper mills includes the following: (based on an analysis of nutrient contents and potential impacts from land application). It can also be • Solid waste volumes should be reduced to the extent used as a neutralization agent for acidic wastewater; feasible through in- situ reuse and recycling of materials, o Deinking sludge (RCF mills) can be used as a filler in example of which include: other paper grades, composted with other organic o Recycling of fiber sludge; materials for preparation of soil products, or else o Reintroducing knots and screenings into the digestion incinerated; process; o Pith (bagasse mills) can be composted with other o Improving sludge dewatering to facilitate burning of organic materials for preparation of soil products or sludge (often in auxiliary boilers, using a support fuel); else incinerated; o Reducing the generation of organic wastes such as o Fiber sludge can be recycled into production on site, bark by debarking in the forest (leaving the bark sold to other mills, or sent off-site for use in other behind as soil conditioner); products. It can also be incinerated or used as landfill o Incinerating organic wastes, such as bark , in steam 11 daily cover material; generating boilers to reduce overall fuel consumption. o Biological sludge can be incinerated in the bark boiler together with fiber sludge, or evaporated and • Additional waste management recommendations include: incinerated in the kraft mill recovery system. It can o Debarking waste 12 should be minimized through clean also be composted with other organic materials for the wood handling followed by segregation of clean preparation of soil products; organic fractions that can be used as a fuel in steam o Tertiary treatment sludge can be blended with other generation while the remaining fraction should be sludge for incineration in the bark boiler as well as landfilled; composted with other organic materials for o Bark ash, wood ash and other ashes may be recycled preparation of soil products. 13 as fill material in construction work, road construction, as a soil conditioning agent, or otherwise landfilled; Noise o Lime mud (Kraft mills) is normally recycled in the mill Pulp and paper mills are inherently noisy due to the large recovery system but excess material can be amount of mechanical equipment, transport vehicles, physical commercially used for liming of acid soils or otherwise landfilled; 13 The applicability of sludge management methods depends on the actual o Green liquor sludge (Kraft mills) can be used as a quality and type of sludge. For example, incineration in the recovery boiler is typically only applicable for biological sludge in Kraft mills. Incineration in a bark daily cover in solid waste landfills after improved boiler or separate incinerator is feasible only for sludge with relatively high contents of organics and high contents of dry solids. Composting is feasible only for sludge with high contents of organics. Sludge from a waste treatment plant needs to be evaluated on a case-by -case basis to establish whether it 11 “Bark” is the main part of the bark removed from the logs which is relatively constitutes a hazardous or a non-hazardous waste and its potential impacts clean and suitable as fuel for a solid fuel boiler. from land application. 12 “Debarking waste” is a smaller fraction of the bark, contaminated with soil and gravel, which may not be suitable as fuel. DECEMBER 10, 2007 8 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP activities, and energy usage, notably vacuum pumps, liquid Chemical hazards pumps and steam generation systems. Guidance for noise Numerous chemicals are used and manufactured in the pulp management is provided in the General EHS Guidelines. and paper industry that can have adverse impacts on worker health and safety. These include: 1.2 Occupational Health and Safety Gases—such as reduced sulfur compounds (kraft pulping), Occupational health and safety issues should be considered as oxidized sulfur compounds, mainly sulfur dioxide (kraft and part of a comprehensive hazard or risk assessment, including, sulfite pulping), chlorine, chlorine dioxide, terpenes and other for example, a hazard identification study [HAZID], hazard and volatile organic compounds, and oxygen; operability study [HAZOP], or other risk assessment studies. The results should be used for health and safety management Liquids—including sodium hydroxide and other caustics, acids planning, in the design of the facility and safe working systems, such as sulfuric acid, cooking byproducts such as turpentine, and in the preparation and communication of safe working sodium hypochlorite, aqueous solution of chlorine dioxide, procedures. hydrogen peroxide, biocides, papermaking additives, solvents, and dyes and inks; and General facility design, operation, and monitoring measures to manage principal risks to occupational health and safety are Solids—including sodium chlorate, sodium sulfate, lime, calcium provided in the General EHS Guidelines. General guidance carbonate, ash, and asbestos (used for insulation). specific to construction and decommissioning activities is also provided along with guidance on health and safety training, Recommended measures to prevent, minimize, and control personal protective equipment and the management of physical, potential worker health and safety impacts from chemicals chemical, biological and radiological hazards common to all include: industries. • Automate pulping and bleaching operations to the extent Occupational health and safety issues for further consideration possible, such that operators can monitor and operate the in pulp and paper mills include: processes from control rooms isolated from potential chemical exposures and other health and safety hazards. • Chemical hazards Effective process control also minimizes the use of • Physical hazards bleaching and other chemicals; • Wood dust • Provide engineering controls, such as automatic digester • Biological agents capping valves; local exhaust at batch digesters and blow • Heat tanks capable of venting at the rate that the vessels’ gases • Confined spaces are released; negative pressure in recovery boilers and • Noise sulfite-sulfur dioxide acid towers to prevent gas leaks; • Radiation ventilated full or partial enclosures over post-digestion vessels; enclosed or ventilated lime conveyors, elevators, DECEMBER 10, 2007 9 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP and storage bins; canopy enclosures with dedicated • Keep sulfur storage bins free of sulfur dust accumulation; exhaust ventilation for each bleaching tower and washer; • Implement an inspection and maintenance program to and enclosures over sheet dryers; 14 prevent and identify leaks, equipment failure, etc. • Install continuous gas monitors with alarms where leaks or generation of hazardous gases may occur, such as chemical recovery, chlorine storage area, chlorine dioxide Physical hazards generator, and bleaching areas, and provide all employees, The most severe injuries in this sector are often attributable to contractors, and visitors in these areas with emergency the failure of lockout - tagout systems. Robust lockout - tagout escape respirators; procedures as described in the General EHS Guidelines • Maintain a current database of all chemicals used and should be implemented. manufactured in the mill, including data on hazards, General Physical Hazards toxicology, biological properties, etc; Recommended measures to prevent, minimize, and control • Identify and prevent possible chemical reactions that can general physical hazards (e.g. trips, falls, and materials handling result in formation of hazardous gases and other hazards) include: substances (e.g., combination of spent sulfate pulping liquor and acids in the wastewater system can generate • Install catch platforms under conveyors that cross hydrogen sulfide). All chemicals used or manufactured at passageways or roadways; the site should be reviewed for reactivity with other classes • Quickly clean up spills; of chemicals used at the facility; • Use non-skid walking surfaces that allow drainage; • Label, mark, package and store all chemicals and • Install guard rails on walkways adjacent to production lines hazardous materials according to national and or at height, and clearly mark traffic lanes for vehicles and internationally recognized requirements and standards; pedestrians; • Ensure contractor personnel, including maintenance • Equip mobile equipment with roll-over protection. contractors retained during shutdowns, are trained in and • Establish routines to ensure that heavy loads are not follow site safety procedures, including use of personal moved by crane over personnel; protective equipment and handling of chemicals; • Train workers in handling of chlorine dioxide and sodium Machine Safety chlorate. Wet sodium chlorate spills with water and keep Pulp mills employ wood processing and other equipment such any contaminated clothing wet until laundered; as debarkers and chippers with the potential to expose workers • Avoid the use of elemental chlorine for bleaching; to severe injury. • Use water-based (rather than solvent- based) inks and dyes; 14International Labour Organization, Encyclopaedia of Occupational Health and Safety, 4th Edition, Chapter 72, Pulp and Paper Industry, Occupational Hazards and Controls. DECEMBER 10, 2007 10 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP Recommendations to prevent, minimize, and control injuries • Establish and follow safety practices for unloading logs, from chipping and debarking equipment include: 15 lumber and chips; 18 • Complete mechanization of log yard activities should be • Equipment with moving parts (e.g., the in-running nips considered to reduce human contact with logs during between the chain and sprocket of conveyors; conveyor handling and stacking activities; drums, drive belts, pulleys, and shafts; rollers on paper • Transport routes within log yards should be clearly machines; shredder feed rolls; etc.) should be fitted with demarcated and vehicle movement should be closely safety guards or interlocks capable of preventing access to controlled; moving parts; • Log stacks should not be higher than a safe height defined • Equipment must be shut off and locked out before by risk assessment which should take account of site- maintenance, cleaning, or repairs are undertaken; 16 specific circumstances including stacking methodology;19 • Workers should be trained specifically in the safe use of • Access to log yards should be restricted to authorized debarking, chipping, and other equipment; personnel; • Work stations should be aligned to minimize human danger • Log decks should have stops, chains, or other guards to from fragments which could arise from breakage; prevent logs from rolling down and off the deck; • Equipment should be regularly inspected and maintained to • Workers should be trained in safe working procedures in prevent equipment failure; log stack and deck areas, including avoidance of falling • All personnel operating cutting equipment should use logs and planning of escape routes; protective eyewear, and other PPE as necessary. • Workers should be provided with protective steel capped boots, hardhats, and high visibility jackets; Log Handling Activities • All mobile equipment should have audible reversing Logs are generally unloaded from railroad cars or heavy trucks alarms. and stacked by machines before being moved to log conveyors and log decks for processing in the pulp mill. Injuries due to vehicle movement in log yards can be severe, in addition to Wood dust injuries from logs that roll off or are dropped by handling Exposure to wood dust is a potential concern in the wood equipment or are dislodged from log stacks. handling area of pulp mills (e.g. in semi-mechanized chippers), as well as in the initial stages of pulping. Exposure to fiber dust Recommendations to prevent, minimize, and control injury in log can occur in paper mills. Paper fiber dust is also a fire hazard. yards include 17: 17 Specific techniques for log receiving and handling can be found at US OSHA (2003), available at: http://www.osha-slc.gov/SLTC/etools/sawmills/receive.html 15 Specific techniques for minimizing injuries associated with cutting and and http://www.osha-slc.gov/SLTC/etools/sawmills/convey.html debarking equipment can be found at US OSHA (2003), available at: 18 See, for example, U.S. Occupational Health Administration regulations for http://www.osha-slc.gov/SLTC/etools/sawmills/log_breakdown.html loading and unloading logs, 29 Code of Federal Regulations (CFR) 16 See, for example, U.S. Occupational Health Administration regulations for 1910.266(h)(6), and Oregon Administrative Rule (OAR) 437-02-312. Pulp, Paper, and Paperboard Mills, 29 Code of Federal Regulations (CFR) 19 Manual stacking operations may typically limit stacking height to 2 meters 1910.261(a), and relevant American National Standards Institute codes, such as while mechanical stacking operations may safely work with greater stacking O1.1-2004: Woodworking Machinery Safety Requirements. heights. DECEMBER 10, 2007 11 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP Recommended measures to prevent, minimize, and control dust measures to prevent, minimize, and control heat exposure in the include: pulp and paper sector include: • Enclose and ventilate saws, shredders, dusters, and wood • Provide air-conditioned control rooms, including in wood chip conveyors; preparation, pulping, bleaching, and paper- making areas; • Consider enclosed chip storage; • Schedule work in hot areas to allow acclimatization and • Avoid use of compressed air to clear wood dust and waste rest periods; paper; • Automate smelt removal from the chemical recovery boiler. • Enclose and ventilate areas where dry, dusty additives are Provide heavy-duty protective clothing to workers unloaded, weighed, and mixed, or use additives in liquid potentially exposed to mo lten smelt or other high- form; temperature materials; • Regularly inspect and clean dusty areas to minimize dust • Implement safety procedures to minimize the potential for explosion risk. smelt/water explosions. Smelt should be transferred at a controlled rate, and recovery boilers maintained to prevent Biological agents water leaks from the tube walls of the boiler. Chemical Biological agents include microorganisms such as bacteria, recovery boiler operations should be shut down at the first fungi and viruses, some of which may be pathogenic. indication of a leak; Microorganisms develop particularly in paper machines’ closed- • Consider use of mobile equipment with air-conditioned loop systems, biological treatment plants for mill wastewaters, enclosed cabs. and water cooling towers. Confined Spaces Recommended measures to prevent, minimize, and control Operation and especially maintenance work may include exposure to biological agents include: confined space entry. Examples include: boilers, dryers, degreasers, digesters, blow pits, pipeline pits, process and • Design biological treatment plants to minimize the potential reaction vessels, tanks, and vats. Impacts and mitigation for growth of pathogenic organisms; measures for confined space entry are addressed in the • Use biocides in cooling water and in pulping and General EHS Guideline. papermaking processes to minimize growth of microorganisms. Noise Heat Two major sources of noise are wood debarking in pulp mills Many pulping operations, including pulp cooking, pulping and the paper machine in paper mills, but other processes can chemical recovery, lime production, and paper drying involve also be noise generators. Use of control rooms, as discussed high temperatures and, in some cases, high pressures. Heat above, is an effective engineering control. Additional protection measures common to most large industrial operations recommendations on the management of occupational noise are are discussed in the General EHS Guideline. In addition, provided in the General EHS Guidelines. DECEMBER 10, 2007 12 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP Radiation management of these issues is presented below and in relevant Certain measurement equipment, particularly in paper mills, sections of the General EHS Guidelines including: Traffic contains radioactive material. These units are typically sealed, Safety; Transport of Hazardous Materials; and Emergency but damage to or maintenance of devices containing radioactive Preparedness and Response. material may result in exposure. These devices should be designed and operated according to applicable national Odors Chemical pulping, and Kraft pulping in particular, generates requirements and internationally accepted standards for malodorous reduced sulfur compounds that can create a occupational 20 and/or natural 21 exposure to ionizing radiation, nuisance for nearby residents. Modern air pollution controls, as such as “International Basic Safety Standard for protection discussed in Section 1.1, prevent the odors formerly associated against Ionizing Radiation and for the Safety of Radiation with pulp mills although emissions can still occur during upset Sources” 22 and its three interrelated Safety Guides. Additional conditions. Therefore, greenfield projects should consider the recommendations on the management of radiation exposure are location and distance of a proposed facility with regards to provided in the General EHS Guidelines. residential or other community areas. 1.3 Community Health Traffic Community health and safety issues during the construction and Pulp and paper mills require a large volume of wood, either as decommissioning of pulp and paper mills are common to those logs or as chips, and export a large volume product, and these of most large industrial facilities and their prevention and control materials are often transported by truck. This can result in a is discussed in the General EHS Guidelines. significant increase in truck traffic in the community. Traffic safety measures are addressed in the General EHS Guideline. Community health and safety impacts primarily occur during the operation phase of pulp and paper facilities and include: • Chemical storage, use, and transport • Odors • Traffic Chemical Storage Use and Transport Major accidents can result in releases, fires, and explosions in pulping or bleaching operations or during product handling and transport outside the processing facility. Guidance for the 20 Organizations processing, or applying radioactive substances for purposes such as medical or industrial processes, education, training, research, etc. 21 Underground mines (other than those for radioactive ore), spas, radon prone areas, etc. 22 IAEA Safety Series No. 115. DECEMBER 10, 2007 13 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP steam- and power-generation activities from sources with a 2.0 Performance Indicators and capacity equal to or lower than 50 MWth are addressed in the Monitoring General EHS Guidelines with larger power source emissions addressed in the Thermal Power EHS Guidelines. Guidance 2.1 Environment on ambient considerations based on the total load of emissions Emissions and Effluent Guidelines is provided in the General EHS Guidelines. Tables 1(a) through 1(l) provide the effluent guidelines and Resource Use Table 2 the emissions guidelines for pulp and paper mills. These Table 3 provides examples of energy use and water guidelines are assumed to be achievable under normal consumption from the pulp and paper sector that can be operating conditions in appropriately designed and operated considered as indicators of the sector’s efficiency and may be facilities through the application of pollution prevention and used to track performance changes over time. The actual control techniques discussed in the preceding sections of this energy consumption depends on the process configuration, document. process equipment, and process control efficiency. Effluent guidelines represent annual average values 23 and are applicable for direct discharges of treated effluents to surface Environmental Monitoring waters for general use. Site-specific discharge levels may be Environmental monitoring programs for this sector should be established based on the availability and conditions in the use of implemented to address all activities that have been identi fied to publicly operated sewage collection and treatment systems or, if have potentially significant impacts on the environment, during discharged directly to surface waters, on the receiving water use normal operations and upset conditions. Environmental classification as described in the General EHS Guideline. These monitoring activities should be based on direct or indirect levels should be achieved, without dilution, at least 95 percent of indicators of emissions, effluents, and resource use applicable the time that the plant or unit is operating, to be calculated as a to the particular project. proportion of annual operating hours. Deviation from these Monitoring frequency should be sufficient to provide levels in consideration of specific, local project conditions should representative data for the parameter being monitored. be justified in the environmental assessment. 24 Monitoring should be conducted by trained individuals following Emissions guidelines are applicable to process emissions. monitoring and record-keeping procedures and using properly Combustion source emissions guidelines associated with calibrated and maintained equipment. Monitoring data should be analyzed and reviewed at regular intervals and compared with 23 Daily averages should not be greater than 2.5 times the annual average the operating standards so that any necessary corrective values. 24 The effluent guidelines are based on production load (e.g. emissions as kg actions can be taken. Additional guidance on applicable per ton of produced pulp or paper). In separate (non-integrated) pulp mills and paper mills, the specific data (e.g. “kg/ton air dry pulp” or “kg/ton paper” ) is sampling and analytical methods for emissions and effluents is unambiguous. In an integrated mill, the emission indicator is usually given as “kg per ton of paper”, which should include the emissions of both the pulp mill and provided in the General EHS Guidelines. the paper mill. If an integrated mill sells both paper and pulp, the most relevant indicator would be “kg/ton pulp total”, where “pulp total” is approximately the sum of produced paper and marketed pulp. DECEMBER 10, 2007 14 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP 2.2 Occupational Health and Safety designed and imp lemented by credentialed professionals 30 as part of an occupational health and safety monitoring program. Occupational Health and Safety Guidelines Facilities should also maintain a record of occupational Occupational health and safety performance should be accidents and diseases and dangerous occurrences and evaluated against internationally published exposure guidelines, accidents. Additional guidance on occupational health and of which examples include the Threshold Limit Value (TLV®) safety monitoring programs is provided in the General EHS occupational exposure guidelines and Biological Exposure Guidelines. Indices (BEIs®) published by American Conference of Governmental Industrial Hygienists (ACGIH), 25 the United States National Institute for Occupational Health and Safety (NIOSH),26 Permissible Exposure Limits (PELs) published by the Occupational Safety and Health Administration of the United States (OSHA),27 Indicative Occupational Exposure Limit Values published by European Union member states, 28 or other similar sources. Accident and Fatality Rates Projects should try to reduce the number of accidents among project workers (whether directly employed or subcontracted) to a rate of zero, especially accidents that could result in lost work time, different levels of disability, or even fatalities. Facility rates may be benchmarked against the performance of facilities in this sector in developed countries through consultation with published sources (e.g. US Bureau of Labor Statistics and UK Health and Safety Executive)29. Occupational Health and Safety Monitoring The working environment should be monitored for occupational hazards relevant to the specific project. Monitoring should be 25 http://www.acgih.org/TLV/ 26 http://www.cdc.gov/niosh/npg/ 27 http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDAR DS&p_id=9992 30Credential professionals may include Certified Industrial Hygienists, 28 http://europe.osha.eu.int/good_practice/risks/ds/oel/ Registered Occupational Hygienists, or Certified Safety Professionals or their 29 http://www.bls.gov/iif/ and http://www.hse.gov.uk/statistics/index.htm equiv alent. DECEMBER 10, 2007 15 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP 3.0 References and Additional Sources Allan M. Springer, Ed.: Industrial Environmental Control – Pulp and Paper Industry, 3rd edition, Tappi Press, Atlanta, Ga., 2000 Environment Canada. 2004. Regulations Amending the Pulp and Paper Effluent Regulations [embedding the Environmental Effects Monitoring requirements under Schedule IV]. Published in Part II of the Canada Gazette on May 19, 2004. European Commission. 2001. Integrated Pollution Prevention and Control (IPPC) Reference Document on Best Available Techniques in the Pulp and Paper Industry. December 2001. Finnish Environment Institute, A Strategic Concept for Best Available Techniques in the Forest Industry, 2001, URL: http://www.ymparisto.fi/download.asp?contentid=10759&lan=en Finnish Environment Institute, Continuum - Rethinking BAT Emissions of the Pulp and Paper Industry in the European Union, 2007. URL: http://www.environment.fi/download.asp?contentid=65130&lan=en International Labour Organization, Encyclopaedia of Occupational Health and Safety, 4th Edition, Chapter 72, Pulp and Paper Industry, Occupational Hazards and Controls. Oregon Administrative Rule (OAR) 437-02-312 Peter N. Williamson, Ed., Patti Turner, Techn. Ed.: Water Use and Reduction in the Pulp and Paper Industry – A Monograph, Canadian Pulp and Paper Association, 1994 Swedish Paper Industry’s Council for Development of Occupational Health and Safety (2005). United Nations Environment Programme (UNEP), 2006. Revised edited draft guidelines on best available techniques and guidance on best environmental practices relevant to Article 5 and Annex C of the Stockholm Convention on Persistent Organic Pollutants. Expert Group on Best Available Techniques and Best Environmental Practices. US EPA: Final Pulp, Paper, and Paperboard “Cluster Rule”. U.S. Occupational Health Administration regulations for Pulp, Paper, and Paperboard Mills, 29 Code of Federal Regulations (CFR) 1910.261 U.S. EPA. 2002. Sector Notebook Project, Profile of the Pulp and Paper Industry, 2nd Edition. EPA/310-R-02-002. November 2002 http://www.epa.gov/compliance/resources/publications/assistance/sectors/noteb ooks/pulp.html DECEMBER 10, 2007 16 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP Annex A: General Description of Industry Activities The main steps in pulp and paper manufacturing are: (a) raw debarking processes, which have substantially been abandoned material preparation (such as debarking and chipping wood), (b) by the industry generate wastewater that contains nutrients, pulp manufacturing, (c) pulp bleaching, and (d) paper fiber, and oxygen-consuming organic compounds such as resin manufacturing, which are described below. Pulp mills and paper acids, fatty acids, etc. mills may exist separately or as integrated operations. Certain mechanical pulping processes, such as stone Raw Material Preparation 31 groundwood pulping, use roundwood; however, the majority of pulping operations require wood chips. A uniform chip size Wood is the predominant source of cellulose fiber for paper (typically 20 mm long in the grain direction and 4 mm thick) is products, although other fiber sources, such as straw, bagasse, necessary for the efficiency of the processes and for the quality and bamboo, are used in areas with limited access to forest of the pulp. The chips are then put on a set of vibrating screens resources, especially in developing countries. Some non-wood to remove those that are too large or small. Large chips stay on plants, such as abaca, cotton, and hemp, are used as the the top screens and are sent to be re-cut, while the smaller source of fiber for specialty applications. chips are usually burned with the bark or may be sold for other purposes. Wood used to make pulp can arrive at the mill in a variety of forms including wood logs, chips, and sawdust. In the case of Non-wood fibers are handled in ways specific to their roundwood (logs), the logs are cut to manageable size and then composition in order to minimize degradation of the fibers and debarked. At pulp mills integrated with lumbering facilities, thus maximize pulp yield. Non-wood raw materials are usually acceptable lumber wood is removed at this stage. At these managed in bales. facilities, any residual or waste wood from lumber processing is returned to the chipping process; in-house lumbering rejects can Pulping Processes be a significant source of wood at such facilities. Raw plant material primarily comprises cellulose fibers, The bark of those logs not fit for lumber is usually removed hemicelluloses, and lignin, a natural binding material that holds mechanically (in a drum debarker) in order to prevent together cellulose fibers in wood or in the stalks of plants. In the contamination of pulping operations32. Depending on the pulping process, the raw cellulose-bearing material (raw plant moisture content of the bark, it may then be burned for energy material or recycled paper) is broken down into its individual production. If not burned for energy production, bark can be fibers, known as pulp. Pulping processes are generally used for mulch, ground cover, or to make charcoal. Wet categorized as chemical and mechanical. Chemical pulping relies mainly on chemical reactants and heat energy to soften and dissolve lignin in wood chips, followed by mechanical 31 Information adapted from U.S. EPA, Sector Notebook Project, Profile of the Pulp and Paper Industry, 2nd Edition, EPA/310-R-02-002, November 2002. refining to separate the fibers. Mechanical pulping often 32 Hydraulic debarking which uses high-powered water jets is considered obsolete and environmentally undesirable due to the high levels of BOD involves some pretreatment of wood with steam heat and/or generated in the effluent. DECEMBER 10, 2007 17 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP weak chemical solution, but relies primarily on mechanical under elevated temperature and elevated pressure, freeing the equipment to reduce wood into fibrous material by abrasive cellulose fibers (pulp). Following digestion, the resulting black refining or grinding. Different pulping processes result in pulp liquor, which contains dissolved organic substances, is with specific properties suited for different end uses. separated from the pulp, called brown stock. The brown stock is treated with oxygen in the presence of sodium hydroxide to Wood-Based Chemical Pulping remove some of the residual lignin in a process referred to as Principal chemical pulping processes include the alkaline sulfate oxygen delignification. The brown stock is then bleached, as (or Kraft) pulping process, acid sulfite, and semi-chemical described below, to achieve desired brightness, strength, and pulping. Kraft pulping represents approximately 80% of current purity of the final pulp product. pulp production worldwide and virtually all new construction. The chemical feedstocks are recovered in what is referred to as Compared with mechanical pulping processes, Kraft and sulfite the liquor cycle. Black liquor is typically concentrated by pulps usually have higher market value and have higher costs of evaporation of water and then burned in a recovery furnace, production. Their fiber quality is better for most purposes, with which destroys the organic constituents and generates heat generally less lignin or other wood constituents and used to make steam for other facility uses. Smelt, a molten salt proportionately more cellulose fiber and more intact fibers. Kraft mixture consisting principally of sodium carbonate (Na2CO3) and and sulfite pulps can be more readily bleached to yield high sodium sulfide, is formed at the bottom of the recovery boiler, brightness or whiteness that is desirable in many paper and is dissolved in an aqueous solution, forming green liquor. In products, and Kraft pulp typically produces a stronger sheet of the causticizer, lime (CaO) is added to the green liquor, which paper or paperboard than other pulping processes. converts sodium carbonate back to sodium hydroxide, forming white liquor, which is used again in the digesters. Lime mud, Kraft Pulping principally comprising calcium carbonate (CaCO3), is also The Kraft pulping method accounts for approximately 80 percent generated in the causticizer. The lime mud is converted back of world pulp production. 33 Kraft pulping has become the into lime by heating in the lime kiln. dominant chemical pulping method because of better fiber strength compared to sulfite pulping, its applicability to all wood Liquid streams from the Kraft pulping process are mostly re- species, and the ability to recover chemical feedstocks used in the pulping operations or, in the case of bleached pulp, efficiently. in the bleach plant. Liquid effluents from brownstock preparation should be limited to small amounts of condensates In the Kraft pulping process, wood chips are combined in a and spills. Gaseous emissions include sulfur dioxide, hydrogen digester with white liquor, an aqueous solution comprising sulfide and other reduced sulfur compounds, nitrogen oxides, principally sodium sulfide (Na2S) and sodium hydroxide (NaOH), and particulate matter. which breaks down lignin and, to a lesser extent, hemicelluloses A typical Kraft pulping process (including bleaching processes, 33European Commission, Integrated Pollution Prevention and Control (IPPC) discussed below) is shown in Figure 1. Reference Document on Best Available Techniques in the Pulp and Paper Industry , December 2001. DECEMBER 10, 2007 18 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP Figure 1. The Kraft pulp manufacturing process for new construction. Use of sodium base and ammonium base Roundwood and sawmill chips has largely been discontinued because of higher costs. Wood yard Chemically treated water Although calcium base is relatively inexpensive, the cooking Stea m chemicals cannot be recovered and are discharged; therefore, it Bark and fines Feed water Wood handling Bark boiler is generally not used in new installations. treatment Steam Knots Black liquor Black liquor Sulfite pulps are easier to bleach than Kraft pulps, which permits Cooking Evaporation Recovery boiler WL Smelt TCF bleaching (see Bleaching, below), and sulfite pulping Brown-stock Stripping Green liquor screening produces fewer malodorous gases and has a higher material (condensate treatment) Cleaned condensate Brown-stock Burnt lime yield than Kraft pulping. However, because of weaker fiber and washing White liquor Causticizing Lime reburning poor recovery technology (apart from magnesium base), the Lime mud Concentrated Fuel oil Oxygen Ox WL White liquor malodorous gases sulfite process has not been competitive and has often resulted delignification oxidation in more water effluents. Other significant limitations of this Post-oxygen Oxygen Liquid oxygen or air process include its much higher net energy consumption than washing preparation Water the kraft process as well as limitations on the use of certain Raw materials River water Water Bleaching Bleaching chem. preparation and chemicals wood species (e.g. pine wood), which limits the raw material Fresh water base. For th ese reasons, most major new chemical pulping treatment Pulp drying Storage investments use the Kraft process. Mechanically cleaned water Process steam Turbine HP steam Bark boiler Chemically cleaned water Semi-Chemical Pulping Fire water In semi-chemical pulping, wood chips are partially digested to Recovery boiler Potable water weaken the bonds between fibers, and then the chips are then LP MP 1 MP 2 Electric power mechanically treated in a refiner, which uses mechanical action to separate the fibers. Semi- mechanical pulping produces pulp with high stiffness that is commonly used in manufacture of corrugated board. The most common semi-chemical pulping process is the neutral sulfite semi-chemical (NSSC) process. Other semi-chemical pulping processes in use include alkaline Sulfite Pulping cooking with sodium hydroxide liquor (soda cooking) or modified The sulfite cooking process is based on the use of aqueous sulfate liquor. sulfur dioxide and a base. The base used affects the process conditions, chemical and energy recovery, water use, and The yield of semi-chemical pulping ranges from 55 to 90 properties of the pulp. Calcium, sodium, magnesium, and percent, depending on the process used; however, pulp residual ammonium have been used, although the dominant sulfite lignin content is also high, so bleaching is more difficult than for pulping process is magnesium sulfite pulping and the calcium Kraft and sulfite chemical pulps. Because the process sulfite process is now considered environmentally unacceptable DECEMBER 10, 2007 19 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP conditions are less severe than for Kraft and sulfite chemical Thermo-mechanical Pulping (TMP) pulp and because semi-chemical pulps are generally not Wood chips are usually washed before thermo- mechanical bleached, the processes are relatively straightforward. In pulping to remove stones, sand, scrap metal or other hard addition, lesser amounts of chemicals are needed for semi- debris that may cause wear or damage to the refiner plates. chemical pulping compared with Kraft and sulfite chemical The washed and screened chips are preheated with steam and pulping. then refined either in a single stage at an elevated temperature and pressure or in a two-stage refining system in which the first Because the cooking liquors from semi-chemical pulping contain stage is followed by a second refining stage under pressure or lower concentrations of organic substances than those from at atmospheric pressure. The pulping of screen rejects is often Kraft and sulfite processes, chemical recovery is more costly, carried out in the second stage refiner. The application of more and some semi-chemical pulping mills treat and discharge the mechanical energy instead of chemical dissolution results in spent liquor with no recovery of the process chemicals. Since more pronounced fiber fragmentation and formation of fine the efficiency of the recovery process is lower, untreated material. TMP pulp is most often used for newsprint. wastewater from semi-chemical mills tend to be more highly concentrated than those from kraft mills. Much of the comparatively high amount of electrical energy required in refiner mechanical pulping is converted into heat as Wood-Based Mechanical Pulping steam that is evaporated from wood moisture and dilution water Mechanical pulping processes include thermo- mechanical in the refiners. Because of the pressurized conditions (pressure pulping (TMP), chemi- thermomechanical pulping (CTMP), and up to 5 bars above atmospheric), a significant amount of the groundwood pulping, as well as other variations. The TMP and steam generated may be recovered and used to produce clean CTMP processes involve reduction of wood chips into pulp in process steam (e. g., for use in paper drying). Part of the mechanical disk refiners, usually after pretreatment of chips with energy may also be recovered as hot water. steam and/or weak chemical solutions. The older groundwood Fresh wood is preferred as raw material. If the wood for thermo- process involves grinding of wood bolts (small logs) into pulp mechanical pulping is stored, it is usually stored in water or against a grindstone. sprinkled with water to prevent drying. Thus, water collection Mechanical pulping gives high yields, but the mechanical systems may be required in the wood yard to avoid discharge of disintegration requires high amounts of electric energy in the water containing organic substances. Part of the organic refining processes. Mechanical pulps are usually used for substances of the wood is dissolved in water and discharged printing and writing papers where high opacity and good ink from the pulping process. However, because the wood loss absorption are needed and for some paperboards where higher during the TMP manufacturing is very low and most of the wood bulk and cheaper pulps are preferred. CTMP may be used for material is converted into pulp, the heat value of the wastewater tissue and fluff pulps as well. in a TMP mill is too low to be recovered in the same way as in a chemi cal pulp mill (e.g., black liquor). Therefore, effluent treatment is necessary at a TMP mill. DECEMBER 10, 2007 20 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP Chemi-thermo-mechanical Pulping (CTMP) dissipate heat, reduce friction, and transport the fibers to the The CTMP process combines the TMP process with a chemical next process stages. impregnation of the wood chips. Washed and screened wood In the Pressure Grinding Process (PGW), the grinding process chips are immersed in an alkaline chemical solution in an takes place at overpressure (up to around 3 bar), which allows impregnation tower. Sodium sulphite (Na2SO3) is primarily used the process to be operated at higher temperatures. The higher for softwoods, and alkaline peroxide has been predominantly temperatures result in more intensive softening of lignin and used for hardwoods. After chemical impregnation, the chips are improved pulp qualities (e.g., higher strength), but the technical pre-warmed, and their temperature increases further in the first and financial requirements are considerably greater. Low- to second stages of subsequent refining. For similar reasons as pressure steam is generated when the pulp is depressurized. TMP, CTMP is often integrated with a paper or board mill; however, CTMP is also manufactured as market pulp. The recovered low-pressure steam is usually used for the production of warm process water. The combination of heat and chemicals softens the lignin and A relatively inexpensive method to improve the quality of facilitates the release of the cellulose fiber s, making pulp with groundwood is the thermogrinding process (TGW). In this increased strength and stiffness, but also resulting in lower process, the heat losses which result from evaporation in the yields and, as a consequence, generation of more pollutants grinding zone are reduced and the process temperature is relative to TMP. As with TMP, the process waters can be optimized with stability controllers instead of increased pressure. recovered economically, and residuals discharged after treatment. Recycled Fiber Pulping (RCF) CTMP was originally applied mainly on spruce wood, but is now Recovered paper has become an increasingly important source applied also on hardwoods with low density, such as aspen. of fiber for papermaking. Currently, nearly 50 percent of the CTMP is used for tissue, paperboard and fluff pulps, but the fiber raw material for papermaking is based on recycled fiber. 34 aspen grades are also used in increasing amounts for printing In the recycling process, recycled paper or paperboard is and writing grades with lower fiber costs than for chemical rewetted and reduced to pulp, principally by mechanical means. pulps. Inks, adhesives, and other contaminants may be removed by chemical deinking and mechanical separation. Because the Groundwood Pulping fibers in recycled paper and paperboard have been fully dried In groundwood pulping, the initial defibration takes place in and then rewetted, they generally have different physical grinders by forcing logs against special rotating grinding stones properties than virgin wood pulp fibers. In some cases, mills with the wood fibers parallel to the axis of a stone. Most of the using recycled paper, without deinking, can operate without any energy put into the grinding process is transformed into heat, effluent discharge due to the use of closed water cycles together which helps to soften the lignin bonds and release the cellulose with small anaerobic or aerobic biological treatment systems to fibers. A shower of water over the grinding stones is used to 34U.S. EPA, Sector Notebook Project, Profile of the Pulp and Paper Industry, 2nd Edition, EPA/310-R-02-002, November 2002. DECEMBER 10, 2007 21 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP remove some dissolved organics from the recycled waters. The thus pulp is produced almost exclusively from wood fiber in most closed cycle processes are practical where the product can regions of the world. However, substantial quantities of non- tolerate a certain degree of dirt and contamination, as in some wood pulp are produced, especially in regions of Asia and Africa packaging and construction paper grades. In some recycle where wood fiber is relatively less abundant and non-wood plants, approximately 30 to 40% of the raw material processed fibers are available. results in sludge that requires management as a solid waste. Bagasse, Straw, Reeds, etc. Without Deinking Most non-wood fibers are relatively short, similar to fibers Processing of recovered paper without deinking is sufficient for derived from hardwood, and therefore are suited to similar applications that do not require high brightness, such as applications, such as writing paper. However, non-wood fibers corrugated board, carton board, and some tissue. are often used for other grades as well, such as newsprint and corrugated board, simply because local wood is not available for With Deinking pulping. Deinking processes are used to remove ink to make the pulp brighter and cleaner. Sometimes bleaching is also applied after Non-wood species normally cook more readily than wood chips. deinking. Recycled fiber with deinking is used for applications Thus, Kraft cooking is normally replaced with soda cooking requiring higher brightn ess, such as newsprint, magazine paper, (sodium hydroxide only), and the charge is usually less. The and tissue. spent liquors usually have lower concentrations of dissolved organics and process chemicals compared with chemical Process waters are similar to those from systems without pulping of wood, thus increasing the cost of chemical recovery. deinking. However, deinking results in lower yields and requires In addition, non-wood pulping plants are normally small, typically additional internal treatment. The pulp yield may be as low as 60 producing less than 100,000 t/yr of pulp, and therefore lack the to 70 percent of the recovered paper entering the process; economies of scale that make environmental investments therefore, as much as 30 to 40 percent of the entering material economical at larger facilities. As a result, many non-wood mills may enter the white water and need to be treated and removed have limited or no recovery of chemicals and have substantially before discharge of the wastewater. higher waste emissions per ton of product than modern Kraft mills. Pulping Based on Non-Wood Raw Materials Non-wood plants normally contain higher amounts of silica than Worldwide, non-wood sources make up about six percent of the wood. Silica causes problems in chemical recovery and also total fiber supply for papermaking. Non-wood fibers are derived adversely affects paper quality. In particular, silica increases from agricultural fibers such as straw and other plant fibers such scaling in the liquor evaporators and reduces the efficiency of as bamboo, bagasse (residual of sugarcane refining), and both the causticizing operation and conversion of lime mud annual fiber crops such as kenaf. In general, non-wood plant (calcium carbonate) to calcium oxide (burnt lime) in the lime kiln. fibers are more costly to collect and process than wood fiber in To counter these affects, non-wood pulping facilities generally regions of the world where wood supplies are adequate, and DECEMBER 10, 2007 22 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP discharge higher proportions of lime mud and purchase higher treatment. Effluents from the bleach plant cannot easily be amounts of lime or limestone as make-up. recirculated into the chemicals recovery mainly because they would increase the build-up of chlorides and other unwanted Cotton and Other Long Fibers inorganic elements in the chemical recovery system, which can Certain non-wood fibers have special and valuable properties cause corrosion, scaling, and other problems. for specialty products. For example, cotton linters, hemp, flax, and abaca fibers are long and useful for products such as Chemical Pulp document papers with water marks, security papers, banknote The chemicals most commonly used in chemical pulp bleaching paper, tea bags, etc. The production of these specialty products plants are sodium hydroxide, chlorine dioxide, oxygen, ozone, is small and, therefore, is of limited concern in terms of potential and hydrogen peroxide. Peracetic acid has recently become environmental impact. commercially available as a bleaching chemical. Chlorine and hypochlorite have largely been phased out as primary bleaching Bleaching chemicals over recent years. Small amounts of chlorine are Bleaching is any process that chemically alters pulp to increase formed as a by-product in most of the chlorine dioxide its brightness. Bleached pulps create papers that are whiter, generation systems, and at least part of this chlorine will be brighter, softer, and more absorbent than unbleached pulps. present when chlorine dioxide is used in bleaching. Chlorine Bleached pulps are used for products where high purity is dioxide and ozone have to be produced on site. Peroxide, required and yellowing is not desired (e.g. printing and writing oxygen, and alkali can be delivered to the mills. Ozone is a very papers). Unbleached pulp is typically used to produce reactive bleaching agent, while chlorine dioxide, oxygen, and boxboard, linerboard, and grocery bags. hydrogen peroxide are less reactive. Any type of pulp may be bleached, but the type(s) of fiber and The introduction of extended cooking and oxygen delignification pulping processes used, as well as the desired qualities and end have resulted in more efficient recovery of organic substances use of the final product, greatly affect the type and degree of and allowed development of and use of chemicals other than pulp bleaching possible. The lignin content of a pulp is the chlorine in bleaching, thereby significantly reducing the total major determinant of its bleaching potential. Pulps with high amount of organic compounds and total amount of chlorinated lignin content (e.g., mechanical or semi-chemical) are difficult to organic compounds generated during bleaching. Enzyme bleach fu lly and require heavy chemical inputs. Excessive treatment before bleaching can also enhance the effectiveness bleaching of mechanical and semi-chemical pulps results in loss of the bleaching chemicals used but typically results in a small of pulp yield due to fiber destruction. Chemical pulps can be loss of yield. bleached to a greater extent due to their low (10 percent) lignin content. A bleach plant consists of a sequence of typically four to five separate bleaching stages. Different chemicals are added at Whereas delignification can be carried out within closed water each stage, and acid and alkali stages are usually alternated. systems, bleach plants tend to discharge effluent to external Each bleaching stage consists of devices for mixing the DECEMBER 10, 2007 23 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP chemicals and the pulp, a bleaching reactor designed with a results in only a minimal reduction in yield. Residual dithionite in suitable residence time for chemical reactions, and washing the pulp can cause corrosion of metallic components equipment for separation of used chemicals and removal of downstream in the process. In mo st mills a metal chelating lignin and other dissolved materials from the pulp. agent (e.g. EDTA, DTPA) is used to prevent degradation of the dithionite. The two main types of bleaching methods in use are ECF (Elemental Chlorine Free--no molecular or gaseous chlorine is Oxidative bleaching uses hydrogen peroxide (H2O2). Peroxide dosed in the bleaching) and TCF (Totally Chlorine Free) bleaching results in an approximately 2 percent reduction in bleaching. ECF bleaching uses chlorine dioxide, alkali for the yield, mainly due to the alkalinity during the bleaching that extraction of dissolved lignin, and peroxide and oxygen for the results in some dissolution of organic substances in the wood reinforcement of the extraction stages. TCF bleaching uses (and in an increase of pollution load). Peroxide bleaching also oxygen, ozone or peracetic acid, and peroxide with alkali for improves the strength and water uptake capacity of the pulp. lignin extraction. Both ECF and TCF bleaching are used at Kraft The bleaching process results in lower brightness in the mills, although ECF is the more common. presence of heavy metal ions; therefore, chelating agents (e.g. EDTA, DTPA) are usually added before bleaching to form Mechanical Pulp complexes with heavy metals (e.g., Fe, Mn, Cu, Cr), which Bleaching of mechanical pulp is based on lignin-saving methods prevents the pulp from discoloring and the peroxide from and is fundamentally different from bleaching of chemical pulps, decomposing. EDTA and DTPA contain nitrogen, which enters which is based on removal of lignin. The bleaching of the wastewater. Introduction of a washing stage between mechanical pulp changes chromophoric groups of lignin pulping and bleaching is effective in reducing the problematic polymers into a colorless form. Thus, the bleaching of metals and can thus reduce the amount of chelating agent mechanical pulp increases primarily the brightness of the pulp needed and improve the effectiveness of the applied peroxide. with minimum losses of dry solids and overall yield. The effect The bleached pulp is acidified with sulfuric acid or sulfur dioxide is not permanent, and the paper yellows with time. As it does to a pH of 5 - 6. not result in permanent brightness gain, bleached mechanical pulp is more suitable for newsprint and magazine paper than for Papermaking books or archive papers. After pulping (and bleaching, if applicable), the finished pulp is processed into the stock used for paper manufacture. Market The lignin- saving bleaching is carried out in one to two stages, pulp, which is to be shipped off-site to paper or paperboard depending on the final brightness requirements of the pulp. The mills, is simply dried and baled during this step. Processing of bleaching stages are distinguished according to the bleaching pulp in integrated mills includes pulp blending specific to the agent applied. desired paper product desired, dispersion in water, beati ng and Reductive bleaching uses sodium dithionite (Na2S203), which refining to add density and strength, and addition of any necessary wet additives. Wet additives are used to create does not dissolve organic material from the pulp, and therefore DECEMBER 10, 2007 24 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP paper products with special properties or to facilitate the papermaking process. Wet additives include resins and waxes for water repellency; fillers such as clays, silicas, and talc; inorganic and organic dyes for coloring; and certain inorganic chemicals (e.g., calcium sulfate, zinc sulfide, and titanium dioxide) for improved texture, print quality, opacity, and brightness. The processed pulp is converted into a paper product via a paper production machine, traditionally a Fourdrinier type machine, but increasingly using proprietary twin-wire systems. In paper machines, the fiber slurry is deposited on a moving wire belt that carries it through the first stages of the process. Water is removed by gravity, vacuum chambers, and vacuum rolls. This excess water is recycled to the fiber recovery step of the process due to its high fiber content. The continuous sheet is then pressed between a series of cylinders to remove more water and compress the fibers. After pressing, the sheet enters a drying section, where the paper fibers begin to bond together as steam heated cylinders compress the sheets. In the calender process, the sheet is pressed between heavy rolls to reduce paper thickness and produce a smooth surface. Coatings can be applied to the paper at this point to improve gloss, color, printing detail, and brilliance. Lighter coatings are applied on- machine, while heavy coatings are performed off-machine. The paper product is then spooled for storage. DECEMBER 10, 2007 25 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP Annex B - Effluents and Emissions Guidelines / Resource Use Benchmarks Table 1 (a)—Effluent Guidelines for Pulp Table 1 (b)—Effluent Guidelines for Pulp and Paper Facilities--Bleached Kraft and Paper Facilities--Unbleached Kraft Pulp, Pulp, Integrated Integrated Parameter Units Guideline Parameter Units Guideline Flow a m 3/ADt 50 Flow a m 3/ADt 25 pH 6 –9 pH 6 –9 TSS kg/ADt 1.5 TSS kg/ADt 1.0 COD kg/ADt 20 COD kg/ADt 10 BOD5 kg/ADt 1 BOD5 kg/ADt 0.7 AOX kg/ADt 0.25 Total N kg/ADt 0.2 Total N kg/ADt 0.2b Total P kg/ADt 0.02 Total P kg/ADt 0.03 Table 1 (c)—Effluent Guidelines for Sulfite Pulp and Paper Facilities—Sulfite Table 1 (d)—Effluent Guidelines for CTMP Pulp, Integrated and Non-Integrated Facilities Parameter Units Guideline Parameter Units Guideline Flow a m 3/ADt 20 Flow a m 3/ADt 55d pH 6 –9 pH 6 –9 TSS kg/ADt 1.0 TSS kg/ADt 2.0 COD kg/ADt 5 COD kg/ADt 30c BOD5 kg/ADt 2.0 BOD5 kg/ADt 1.0 AOX kg/ADt 0.005 Total N kg/ADt 0.5 Total N kg/ADt 0.2 Total P kg/ADt 0.05 Total P kg/ADt 0.01 DECEMBER 10, 2007 26 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP Table 1 (e)—Effluent Guidelines for Pulp and Paper Facilities—Mechanical Table 1(f)—Effluent Guidelines for Pulp Pulping, Integrated and Paper Facilities—Recycled Fiber, Without Deinking, Integrated Parameter Units Guideline Parameter Units Guideline Flow a m 3/ADt 20 Flow a m 3/ADt 10 pH 6 –9 pH 6 –9 TSS kg/ADt 0.5 TSS kg/ADt 0.15 COD kg/ADt 5.0 COD kg/ADt 1.5 BOD5 kg/ADt 0.5 BOD5 kg/ADt 0.15 AOX kg/ADt 0.01 AOX kg/ADt 0.005 Total N kg/ADt 0.1 Total N kg/ADt 0.05 Total P kg/ADt 0.01 Total P kg/ADt 0.005 Table 1(g)—Effluent Guidelines for Pulp and Paper Facilities—Recycled Fiber, Table 1 (h)—Effluent Guidelines for Pulp and With Deinking, Integrated Paper Facilities—Recycled Fiber Tissue Mills Guideline Parameter Units Parameter Units Guideline Flow a m 3/ADt 25 Flow a m 3/ADt 15 pH 6 –9 pH 6 –9 TSS kg/ADt 0.4 TSS kg/ADt 0.3 COD kg/ADt 4.0 COD kg/ADt 4.0 BOD5 kg/ADt 0.5 BOD5 kg/ADt 0.2 AOX kg/ADt 0.005 AOX kg/ADt 0.005 Total N kg/ADt 0.25 Total N kg/ADt 0.1 Total P kg/ADt 0.015 Total P kg/ADt 0.01 DECEMBER 10, 2007 27 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP Table 1 ( i )—Effluent Guidelines for Pulp and Paper Facilities—Uncoated Fine Table 1( j )—Effluent Guidelines for Pulp and Paper Facilities—Coated Fine Paper Paper Mills Mills Parameter Units Guideline Parameter Units Guideline Flow a m 3/ADt 15 Flow a m 3/ADt 15 pH 6 –9 pH 6 –9 TSS kg/ADt 0.4 TSS kg/ADt 0.4 COD kg/ADt 2.0 COD kg/ADt 1.5 BOD5 kg/ADt 0.25 BOD5 kg/ADt 0.25 AOX kg/ADt 0.005 AOX kg/ADt 0.005 Total N kg/ADt 0.2 Total N kg/ADt 0.2 Total P kg/ADt 0.01 Total P kg/ADt 0.01 Table 1 (k)—Effluent Guidelines for Pulp Table 1 (l)—Effluent Guidelines for Pulp and and Paper Facilities—Tissue Mills Paper Facilities—Fiber Preparation, Non- Wood Parameter Units Guideline Parameter Units Guideline Flow a m 3/ADt 25 k Flow a m 3/ADt 50 pH 6 –9 pH 6 –9 TSS kg/ADt 0.4 TSS kg/ADt 2.0 COD kg/ADt 1.5 COD kg/ADt 30 BOD5 kg/ADt 0.4 BOD5 kg/ADt 2.0 AOX kg/ADt 0.01 Total N kg/ADt 0.5 Total N kg/ADt 0.25 Total P kg/ADt 0.05 Total P kg/ADt 0.015 DECEMBER 10, 2007 28 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP Sources: European Commission. 2001. Integrated Pollution Prevention and Control (IPPC) Reference Document on Best Available Techniques in the Pulp and Paper Industry. December 2001; and U.S. EPA Effluent Guidelines for the Pulp, Paper, and Paperboard Point Source Category, 40 CFR Part 430. Notes: kg/ADt = kilograms of pollutant per 1,000 kg of air dry pulp a Cooling water and other clean water are discharged separately and are not included. b Any nitrogen discharge associated with the use of complexing agents should be added to the figure of tot -N. c Because of higher kappa number after cooking for magnefite process the BAT associated level is 35 kg COD/ADt. d Does not include process water from the paper mill in integrated sulfite pulp mills. DECEMBER 10, 2007 29 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP Table 2—Emission Guidelines for Pulp and Paper Facilities Guideline Parameter Type of Mill Units Value TSP Kraft, bleached kg/ADt 0.5 Sources: European Commission. 2001. Integrated Pollution Prevention and Kraft, Control (IPPC) Reference Document on Best Available Techniques in the Pulp unbleached— kg/ADt 0.5 Integrated and Paper Industry. December 2001; and U.S. EPA National Emission Standards for Hazardous Air Pollutants For Source Categories, 40 CFR Part 63. Sulfite, integrated and non-integrated kg/ADt 0.15 Notes: SO2 as S Kraft, bleached kg/ADt 0.4 TSP= total suspended particulates Kraft, SO2 = sulfur dioxide unbleached— kg/ADt 0.4 S = sulfur Integrated NO2 = nitrogen dioxide Sulfite, integrated kg/ADt 1.0 N = nitrogen and non-integrated TRS = total reduced sulfur compounds Kraft, bleached 1.5 for hardwood Kg/ADt = kilograms of pollut ant per 1,000 kg of air dry pulp pulp NOx as NO2 kg/ADt 2.0 for softwood pulp Kraft, kg/ADt 1.5 for unbleached— hardwood Integrated pulp 2.0 for softwood pulp Sulfite, integrated kg/ADt 2.0 and non-integrated TRS as S Kraft, bleached kg/ADt 0.2 Kraft, kg/ADt unbleached— 0.2 Integrated DECEMBER 10, 2007 30 Environmental, Health, and Safety Guidelines PULP AND PAPER MILLS WORLD BANK GROUP Table 3—Energy and Water Consumption Reported Ranges Mill Type Water Heat Electrical Source: European Commission. 2001. Integrated Pollution Prevention and Consumption Energy Energy Control (IPPC) Reference Document on Best Available Techniques in the Pulp (m3/t)a (GJ/t) (kWh/t) and Paper Industry. December 2001 Kraft Pulping, bleached 20 – 100b 10 - 14 600 – 1200i Notes: Sulfite Pulping a. Clean cooling water is generally not reported as part of the water (magnesium base) 40 - 100 consumption. Mechanical Pulping-- Groundwood 5 – 15 1100 – 2200c b. Reported quantities greater than about 50 m3/t probably include cooling water. Mechanical Pulping--TMP 4 – 10 1800 – 3600d c. Approximately 20% of energy is recoverable as hot water. Mechanical Pulping— 15 - 50 1000 – 4300e d. Approximately 20% of energy is recoverable as hot water, and about 40 – CTMP 45% of energy is recoverable as steam. Recovered Paper Mill— Uncoated Folding 2 – 10 e. Water consumption in tissue mills is highly dependent of the process Boxboard conditions (e.g., machine speed) and product (e.g., basis weight). Because of Recovered Paper Mill— Coated Folding Boxboard 7 – 15 the low basis weight of the product, water consumption per ton of product can be higher than for other types of paper mills. Recovered Paper Mill— Corrugated Medium and 1.5 – 10 f. For RCF based tissue; includes RCF processing Packaging Paper g. May include water used in pulp processing Recovered Paper Mill— h. Includes water used in pulp processing. Newsprint 10 – 20 i. Modern bleached kraft mills are net exporters of electricity typically generating Recovered Paper Mill— Tissue 5 – 100c about 30% more than they consume by burning black liquor and bark. Recovered Paper Mill— Writing and Printing 7 - 20 Paper Paper Mill—Tissue 10 – 50f 500 – 3000 Paper Mill—Printing and 5 – 40g 500 – 650 Writing Paper, Uncoated Paper Mill—Printing and 5 – 50g 650 - 900 Writing Paper, Coated Paper Mill—Paper Board 0 – 20h ~550 - 680 Paper Mill—Specialty 10 - 300 Paper DECEMBER 10, 2007 31