Pollution Prevention Opportunities in the Forestry and Sulfite Pulp Processing Industries

Pacific Northwest Pollution Prevention Research Center __ Funded by a grant from the Pollution Prevention Office of the Alaska Department of Environmental Conservation

The Pacific Northwest Pollution Prevention Research Center (PPRC) is a public nonprofit organization serving Alaska, ldaho, Oregon, Washington, and British Columbia. The PPRC sponsors research on pollution prevention, analyzes available technology, hosts forums, acts as an information clearinghouse, and serves as a link between public and private groups.

Distribution of this report to other interested parties is encouraged, provided appropriate credit is given to the PPRC. For reprint permission, more information on PPRC activities, or additional copies of this report, please contact: PPRC, 1326FifthAve., Suite650, Seattle, WA 98101 Telephone: (206) 223 -1 15 1 Fax: (206)223-1165

The PPRC wishes to extend its gratitude to the supporters who make the PPRC’s work possible:

Corporate Donors State and Provincial Contributors The Boeing Company State of Alaska ARC0 State of Idaho Hewlett-Packard State of Oregon Weyerhaeuser State of Washington American Electronics Association Province ofBritish Columbia British Petroleum BurlingtonEnvironmental Donors of In-Kind Support Conoco Battelle Pacific Northwest Laboratories ECDS Battelle Seattle Research Center Intel Landau Associates, Inc. Ross & Associates Environmental Perkins Coie, Legal Counsel Consulting, Ltd. PPRC Supporters Federal Contributors Anchorage Green Star Program U. S .Environmental Protection Agency Idaho Council on Industry and the Environment U. S. Department of Energy Municipality of Metropolitan Seattle (Metro) Idaho Operations Office Oregon Environmental Council Richland Operations Office Oregon State Public Interest Research Group Washington Toxics Coalition Waste Information Network 1 Acknowledgements

The PPRC is indebted to many individuals for assistance with this report and the Northwest Industry Roundtable on whichit was based. Funding for the roundtable was provided by agrant from the PollutionPrevention Office ofthe Alaska Depart- ment ofEnvironmenta1Conservation (ADEC). Draft versions ofthe report were reviewed by James Evensen, formerly with Alaska Pulp Corporation; Robert Goff, ADEC/SERO; Dick Stokes, ADEC/SERO; Tom Thorburn, Western Pulp; and David Wigglesworth, ADEC PollutionPrevention Ofice.

Above all, the PPRC wishes to thank the roundtable attendees (listed in Appendix A) for theirwillingness to share the information, ideas and suggestions that form the basis ofthis report.

Table of Contents

Introduction ...... i

AlaskanForestry Indcstry ...... 2 ...... 2 try to Date ...... 2 Environmental Research Opportunities in Forestry ...... 2 Wood Pulping Industry ...... 5 ...... 5 Mechanical Pul ...... 6 ...... 6 ...... 8 ...... 11 ties ...... 12 Additional PollutionPreventionOpportunities ...... 13 Pollution PreventionResearch Opportunities for the Sulfite Pulping Process ...... 14

Appendix A: Roundtable Attendees Appendix B : Additional Sources ofInformation Appendix C: Bibliography

Pollution Prevention Opportunities in the Forestry and Sulfite Pulp Processing Industries

A Northwest Industry Roundtable Report

INTRODUCTION

The Pacific Northwest Pollution Prevention Research Center (PPRC) held a roundtable discussion on pollution prevention issues in the Alaskan forestry and sulfite pulp processing industries onMarch 19, 1993, in Sitka, Alaska. The purpose ofthe roundtable was to share pollution prevention experiences and to identifjr areas for hrther research. Representatives ofthe sulfite pulping industry, Alaska’s Department of Environmental Quality, Kenai’s Economic Development Borough Forest Resources representatives, environmental activists from the Sitka area and thePPRC participated. Funding for the roundtable was provided by a grant from the Pollution Prevention Office ofthe Alaska Department of Environmental Conservation (ADEC).

The ADEC and PPRC held this roundtable on forest products and sulfite pulp mills for two reasons: because these are vital PacificNorthwest industries with significant waste streams and because the pulping industry is so capital intensive that new technology must be demonstrated before it can be implemented. This meeting provided an opportunity for foresters and pulp mill representativesto share proven pollution prevention technology and identifl areas for future research. Representativesof the pulp mills also shared with forest-resources people the holistic view ofpollution prevention opportunities for the industry.

The segment ofthe roundtable on pulp mills concentrated on sulfite pulp mills. This is because the only two mills in Alaska are sulfite mills and because there is little available research data on this type of pulp mill. To date, the majority ofpollution prevention research on pulp mills is on kraft mills, which have been the focus because they account for large percentage ofthe mills in theindustry. Representatives fiom one of the Alaskamills and the only sulfite mill inBritish Columbia attended the roundtable.

Following an introduction of organizers and attendees, the roundtable participants discussed current and emerging practices in the Alaskan forestry and sulfite pulping industries. The pollution prevention and environmental conservation activities discussed are summarized in this report, along with additional pollution prevention opportunities and research needs that were identified. Background on the processes and wastes in the timber harvesting and wood pulping industriesis provided. Appended to this report are lists ofroundtable participants, sources ofadditional information, and a bibliography. Pacijc Northwest Pollution Prevention Research Center

ALASKAN FORESTRY INDUSTRY

B acknround The forests of Southeastern Alaskaare wet and remote. These conditions make access to logging sites difficult and expensive, and require that workers live on-site. Alaskan pulp mills rely on northern soflwood harvested from the Tongass National Forest, a rain forest with many trees 400-500 years old. Although the Tongass forests are healthy, areport by theKenaiPeninsulaBorough-EconomicDevelopmentDistrict estimates that more than 50 percent ofthe spruce on the Kenai Peninsula have been infested by the spruce bark beetle and will die (KPB, 1993). The borough is trying to interest timber companies in salvaging usable trees. Its report suggests that selective harvesting would help contain the infestation, reduce fire danger, andgive economic stability to the region.

Within the Tongass, timber companies harvest an area of approximately two million acres on a rotating 125-year cycle. The United States Forest Service supervises harvesting activity on most federal land. Alaska’s Department ofNatural Resources oversees all logging activities on non-federal land. A mixture of federal regulations, site-specificuse directives, and state and regional best management practices, such as those established by Alaska’s Forest Practices Act of 1990, guide logging activities (ADNR, 1990). Environmental concerns throughout Alaska and the contiguousUnited States continue to raise compliance costs for timber companies.

Conservation Efforts in Forestrv to Date To protect forest waterways from eroded sediment, federal authorities have mandated a 100-foot unlogged buffer around all Class 1 waters and Class 2 tributaries as defined by state fish habitat designations. These buffers are intended to filter out erosion before runoff enters a stream. The adequacy ofthe 100-foot buffer is debated between timber and environmental interests. In addition to the buffer requirement, there are federal guidelines for timber roads that cross protected waterways.

In a related effort, forestry researchers are trying to minimize compaction caused by heavy transportation and yarding (timber collecting) equipment. Equipment recommendations are site-specific and are available to fit to local conditions. In Southeast Alaska, the wet weather and steep slopes dictate that cut logs be yarded using “highlead suspension” with one or both ends ofthe log suspended in air. Yarding alternatives such as balloons and helicopters have been tried, but balloons do not have the lift characteristics necessary and helicopters are too expensive to be generally cost-effective.

Environmenta1 Research Opportunities in Forestry The group discussed what could be done to help the timber industry reduce the wastes and environmental impacts caused by logging. The proposed projects and related opportunities are summarized below.

Contain Erosion from Roads Logging roads are amajor source of sediment contamination in streams. It is common to use mats oftires connected by steel cable to protect bridges when heavy equipment is driven across. One proposal to

2 Pollution Prevention Opportunities in the Forestry and Suljite Pulp Processing Industries

contain the soil that is eroded fromroads involves placing rows oftires connected by steel cable along the roads’ edges.

Use Remote Sensing to Avoid Sensitive Areas Aerial photography is used to assess timber sales and survey work sites. Newly available computer enhancement methods could allow the locations ofplannedroads, camps, and staging areas to be carefully selected. Research to find remote sensing techniques that can identifj sensitive areas will lead to enhanced environmental protection.

Minimize Logpinp Camp Waste Although rare in the contiguousUnited States, logging camps are still used in Alaska and British Columbia. These remote camps have waste streams similar to remote residential communities. The establishment of safe and efficient waste management and reduction programs in remote communities is hampered by the distance to solid and hazardous waste management facilities, recycling markets, and other services; difficultieswith wastewater treatment systems appropriate for small populations and inclement weather. Additional research should focus on characterizing the waste streams and identifling possible waste reduction practices. In general, aguide to waste reduction practices for remote communities would be useful.

Recvcle Equipment Maintenance Wastes The timber industryuses heavy harvesting equipment that generates waste fluids, tires, and worn parts. While most ofthese wastes are recyclable, the logistics and transportation costs associated with recycling are prohibitive in Alaska. Efforts have been made to develop markets by linking communities through “milkrun” waste pickups that collect like wastes. A study evaluating alternatives, such as on-site fluid recycling using mobile treatment units, may improve the feasibility ofrecycling opportunities for logging camp wastes.

Mark Logs without Paint Paint is used to mark the logs leaving a site. A study to determine whether bar-coding could be used to identifl and track logs was suggested. Bar-coding would reduce the use oftoxic materials, eliminate container waste, and improve inventory management.

Reduce Forest Floor Compaction Reducing tire pressure reduces compaction of the forest floor. However, reduced tire pressure increases the wear rate ofthe tires. A study should be done to determine optimum tire pressure in order to minimize forest floor compaction and waste tire generation. Other ways to reduce forest floor compaction include: padding log storage areas with needles and branches, “tabling” logs to keep them offthe ground as much as possible, and restricting vehicle movement to confine impact.

Use Life-Cvcle Analvsis to Select Loggina Svstem Various timber harvesting systems are used inNorth America. These systems have different equipment requirements, environmental impacts, and resulting timber quality. The group suggested that the method ofusing terrain and project goals to select a logging system be refined so that the least damaging system is identified.

5 PacrJc Northwest Pollution Prevention Research Center

Improve Loa Transfer Facilities Log transfer facilities use slides to move logs into waterways fortransport to pulp mills. The slides remove bark, which then collectsunderwater. The bark can cover anareaup to anacre, several feet deep. The immediate impact is on benthic communities (such as crustaceans and worms) as local populations are topped and smothered by the bark. The bark adds biological oxygen demand (BOD) to the water. BOD is a measure ofthe tendency ofan effluent to consume dissolved oxygen from receiving waters. The bark, therefore, depletes oxygen levels and releases high concentrations of lignins and tannic acid that are toxic to organisms.

An alternative log entry method using a crane and low entrance velocity reduces bark removal. Unfortunately, this method may be too expensive to operate given the low profit margin ofthe logs being harvested. The group suggested that a study be done to find an inexpensive and less harmful way to get the logs into the water.

Evaluate Loa Transportation Themill operators suggested that logs transported in marine waters may pickup salts that later contribute to the production of higher levels of TCDD (dioxin) during the bleaching process. They suggested that log quality, transportation cost, and dioxin production be evaluated for water and land transported logs.

Reduce Herbicide & Pesticide Contamination The pesticides and herbicides used to protect trees contaminate soil and streams, damaging wildlife habitats. Research opportunities for reducing pesticide and herbicide contamination include spot application ofchemicals and/or using chemicals with a narrow scope of activity. Pollution Prevention Opportunities in the Forestry and Sulfite Pulp Processing Industries

WOOD PULPING INDUSTRY

Overview The process of separating the fibers in wood chips into individual fibers is called pulping. Pulping strives to separate the fiber, made ofcellulose, from the lignin and hemicellulose that are also present in wood. Lignin is a complex, polymeric substance which, with cellulose, causes the strengthening and thickening of plant cell walls and forms the bulk ofthe woody structure in plants (Le. the “glue” that holds the fibers together). Hemicellulose is a fiber similar to cellulose but it is not as strong and is easier to dissolve. There are roughly equal amounts of cellulose, lignin, and hemicellulose in wood. The pulp industry’s challenge is to separate the fibers while preserving their length and durability.

The two major markets for purified pulp are paper products manufacture and chemical “dissolving pulp” applications, such as rayon, cellophane, and explosives manufacturing. A variety of pulping techniques and bleaching chemistries are available to extract cellulose fiber from wood. The availability ofwood and the desired end product influence the selection of the pulping process and the resulting pulp quality. Table 1 shows the number ofpulping facilities in the PacificNorthwest and the pulping methods they use.

Table 1. Pulpinn Methods Used by PacificNorthwest Pulping Facilities

British AREA: Washington Oregon Idaho Alaska Columbia TOTAL PULP MILLS: 24 21 1 2 34

I TYPESOFMILLS: I

Source: Pulp & Paper 1990 North American Factbook-Fiber: Pulping processes

As showninTable 1, thereare atotal ofnine sulfitemillsinthePacificNorthwest, withbothmillsin Alaska being sulfite mills. A brief description ofthe sulfite pulping process is included below after a description of the mechanical and kraft pulping methods, which are provided for informational and comparative purposes. Following the pulping methods, a briefdiscussion ofbleaching is provided since the bleaching process is often located at the same plant as the pulping operations. The process descriptions are followed by a discussion ofpulping waste streams and pollution prevention activities and opportunities.

5 Pacific Northwest Pollution Prevention Research Center

Mechanical Pulping The separation ofwood cells to obtain the fiber can be done by either mechanical or chemical means. In mechanical pulping, the fibers are separated by grinding up the wood. Mechanical pulping is used primarily for producing items such as newspaper stock and other medium-weight paper. While mechanical pulping has a high fiber yield, the fibers are damaged and the remaining ligninimparts undesirable properties to writing paper or other paper products. For example, paper derived from mechanical pulping process is relatively weak and easily turns yellow. Therefore, mechanical pulping cannot substitute for chemical pulping inmost applications.

Chemical Pulping Chemical pulping removes most of the lignin before separating the fibers, and subsequent bleaching is used to remove the residual lignin. Undamaged, lignin-free fibers form strong paper with brightness stability. Therefore, the chemical pulping method is used to manufacture materials such as rayon, cellophane, and most paper. A disadvantage of chemical pulping is the low yield ofpulp per ton ofwood. This disadvantage is partially offset by recovering the dissolved wood from the pulping step and burning it to generate energy. Two types ofchemical pulping, the kraft and sulfite methods, are described below.

Kraft Pulping The predominant chemical pulping technology used in theunited States and Canadais the kraft process. Kraft pulping gradually achieved dominance as a result of continued refinements, such as extended delignification (whichis amethod wherethe cooking time ofthe pulp is extended to further separate the fibers without the detrimental effects that would normally accompany increased cooking time, such as reduced quality and yield), and because it has the strength necessary for many paper products, such as paper grocery sacks.

Figure 1, on page 7, shows a simplified process diagram ofa typical kraft pulp mill. In the kraft process, a mixture of sodium hydroxide and sodium sulfide (called white liquor) is mixed with wood chips in a digester at very high pH and cooked to convert the wood chips into pulp. The pulp is then separated from the spent pulping liquor by a washing step and can now be used in its natural brown color or bleached and dyed to other colors for product use.

The spent pulping liquor is then concentrated in a series ofevaporators, and is referred to as strong black liquor after this evaporative step. The strong blackliquor is burned in a recovery boiler and the inorganic chemicals recovered in the form ofamolten smelt. The energy produced by this burning is recovered for use in the plant (i.e. to make steam).

The smelt, which contains sodium sulfide and sodiumcarbonate, is then dissolved and converted back into white liquor by the addition of calcium hydroxide in a causticizer. The calcium hydroxide is recycled by burning precipitated calcium carbonate from the causticizer in a lime kiln and slakingthe calcium oxide from the kiln, thereby producing calcium hydroxide for use in the causticizer.

6 Pollution Prevention Opportunities in the Forestry and Sulfite Pulp Processing Industries

Figure 1. SimplifiedProcess Diagram of a Typical KraRPulp Mill

Steam to process Gas to treatment I Strong black liquor < Evaporators

Smelt Steam Weak washwater ., -1 DissolvingL ‘I tank I ElClarifier + Dregs Digester

0 0 ElWasher I Weak liquor

Pulp

7 Pacific Northwest Pollution Prevention Research Center

Sulfite Pulping The chemical pulping alternatives to the kraft process are the sulfite, the soda-anthraquinone, and the solvent pulping processes. Of these chemical alternatives, sulfite pulping was the focus ofthe roundtable because the two mills that participated in this roundtable are sulfite mills, and there has been much less pollution prevention research done for these facilities, as compared with kraft mills.

Figure2, on page 9, shows a simplified process diagram ofa typical sulfite mill. In the sulfite process, wood chips are cooked with a cooking acid for six to nine hours at an elevated pressure. The cooking acid is a solution ofbisulfite in water that contains an excess of dissolved sulfbr dioxide. The cooking can be based onmagnesium, ammonium, or several other similar metals. The two Alaska mills base their cooking on magnesium and the one sulfite mill in British Columbiais based on ammonium. The resulting pulp quality is regulated by chemical composition and temperature.

Following chip digestion, the pulp is washed using countercurrent washes or diffusion techniques to separate spent digestion chemicals from the pulp. The spent digestion liquors are evaporated and then burned in a fbrnace for energy recovery. After washing, the pulp is screened to remove undigested bark and chips, centrifugally cleaned and prepared for bleaching.

The sulfite process has a higher pulp yield than the kraft method, but kraft pulp is stronger. Sulfite pulping was popular for making paper in the 1950sbut now represents only four percent ofNorth American paper production. Even though sulfite pulps have less pulp strength than kraft pulps, sulfite pulps are preferred for tissue papers, rayon, acetate and other chemical applications.

Bleaching Bleaching is a process that lightens or whitens the cellulose fibers in pulp through chemical reactions. This is accomplished by oxidizing and removing residual ligninfiom the fiber. For this reason, bleaching can be considered an extension ofthe pulping process. Pulping cannot beused to remove all the lignin because pulping chemicals are not selective enough and would weaken cellulose fibers. Therefore, residual lignin must be removed with selective bleaching chemicals. A simplified process diagram of a typical bleaching process is shown in Figure 3, on page 10.

Usually, bleaching effluent contains chlorides that prevent it fiom being recycled for energy recovery, and requires that it be treated to satisfy its biological oxygen demand and detoxified before discharge. Bleaching chemicals are oxidizing agents that break down the lignin structure to make it soluble in alkali or sodium hydroxide (NaOH). The oxidizing chemicals are not interchangeable except that chlorine can usually be replaced with chlorine dioxide. They have different efficiency, reactivity, selectivity, bleaching ability, and environmental impacts.

Chlorine is the most technically effective bleaching chemical, but its use is under scrutiny because it contributes to the formation of TCDD (dioxin) and TCDF (furan). These toxins may be released to the environment in the bleaching wastewater stream. The bleaching process is complicated by the fact that none ofthe bleaching chemicals can be used alone, and efficiency is increased by separating oxidizing treatments with alkaline extraction stages. The resulting multistage bleaching sequence removes the bulk

8 Pollution Prevention Opportunities in the Forestry and Su@te Pulp Processing Industries

Figure 2. SimplifiedProcessDiamamofaTypical SulfitePulp Mill

Wood chips

To stack Cooking liquor Digester <

Blow gas to treatment Absorbers

Gas to treatment

$ISpent liquor Evaporators Pulp LI--

Sulfur Water and makeup magnesia or ammonia

9 PaciJc Northwest Pollution Prevention Research Center

Figure 3. Simplified Process Diagram of a Typical Bleaching Operation (Ceded Process)

Pulp from digester/w asher

Storage ,+ Wash tank water

D E

Chlorine Sodium dioxide hydroxide

Chlorine dioxide SodiumI hydroxide Alkali and and Acid I chlorine gas oxygen Bleached Pulp Pollution Prevention Opportunities in the Forestry and Sulfite Pulp Processing Industries

ofresidual lignin in its first two stages. Therefore, these two stages have the greatest environmental impact. For example, most dioxins are formed in the first oxidizing stage and liberated in the alkaline extraction stage that follows.

Concern over the generation of chlorinated organics, measured as adsorbable organic halogens (AOX), has started a trend toward using chlorine dioxide to replace chlorine in the first stage and for using oxygen in the first alkaline extraction stage. Oxygen can also be used in a first bleaching stage to remove about 40 percent ofthe residual lignin. Using oxygen in the first stage decreases the amount of chlorine required inlater stages, resulting in a corresponding reduction in the generation of chlorinated organic compounds, total dissolved organics, and color. Another attractive feature ofthis practice is that the effluent from the oxygen stage contains no chlorides and, therefore, can be burned for energy recovery.

Pulp from a sulfite mill is less dependent on chlorine-based chemicals than pulp from the kraft process because the pulp derived from the sulfite method is brighter. Some pulps from the sulfite process are not bleached at all, while others are bleached using ozone or hydrogen peroxide. The lack ofprecursors and the relatively low lignin content of sulfiteunbleached pulps results in products that have non-detectable levels of chlorinated dioxins and hrans. However, dissolving pulp by the sulfite process still depends on chlorine and chlorine-containing compounds. A study of sulfite mills indicates that they produce more AOXthan kraft mills, whichis surprising because it is harder to bleach kraft pulp. Most investigators blame the higher level ofextractives in sulfite processing pulp for the higher AOX production. In kraft pulping, extractives react to form water-soluble sodium soaps that can be effectively removed. In contrast, sulfite pulping tends to leave extractives in the pulp as a calcium or magnesium salt (Hickman, 1993).

Pulping Waste Streams The primary waste streams from pulp mills are wastewater effluent from the wood chip digestion, liquor recovery, washing, bleachingprocesses, and air emissions. The wastewater eMuent from pulp mills has avery high BOD (USGS, 1990). HighBOD can cause problems by consuming the oxygen necessary to support aquatic life. Other effluent problems associated with sulfite mills includes various nutrients, sulfur compounds, elevated temperature, and color. At some mills, storm water runofffromwood and wood chip storage areas is also sent to the treatment plant for removal oforganic material and debris (USEPA, 1976).

Mills also may discharge toxic materials, including metals such as copper, cadmium, chromium, zinc, mercury, and nickel, as well as solvents and acids (NPDES, 1990). The most well-knownmill discharges are the chlorinated compounds, dioxin, and furan. As mentioned earlier, the dioxin compounds may be generated during chlorine bleaching. Although the amount of dioxin released is small, dioxin’s toxicity has made chlorine elimination a primary goal.

Sulfite pulp mills have sulfur dioxide emissions from their chip digestion and liquor recovery processes and acid generating plants. Most of these emissions come from the recovery boiler where waste liquor is converted into the steamused for mill operations. Most millsuse absorption towers to scrub sulfur dioxide wastes and regenerate cooking acid. Fugitive emissions are common in this process. Wastes generated in the pulping process, including wood chips, bark, and concentrated liquor, are burned in the facility’s recovery boiler. The boiler ash is the only remaining waste. The six largest chemical emissions from the sulfite pulp mills in Alaska according to the 199 1 Toxic Release Inventory are listed in Table 2 on page 12.

11 Pacific Northwest Pollution Prevention Research Center

Table 2. 199 1 Toxic Release Inventory Data for Alaskan Pulp Mills

SUBSTANCE REPORTED RELEASE IN 1991 (POUNDS) Methanol 2,673,320 Hydrochloric acid 2,034,600 Chlorine and chlorinated compounds 800,000 Ammonia 445,500 Suhr 3 19,000 Acetone 100.550

Source: Environmental Protection Agency

Pollution Prevention Activities Avariety ofpollution preventionactivitieshave already beenundertakenby thetwo millsthat participatedin the roundtable. A summary of these activities is provided below.

Alaska Pulp Corporation - Sitka, Alaska AlaskaPulp has completed the following pollution prevention activities:

0 Installed a dry debarking system that saves 10 million gallons of water per day.

0 Converted to water-based defoamers and pitch dispersants that do not contain TCDD or TCDF precursors.

0 Started using evaporator condensate, a weak acid, to remove scale from the packing in the recovery boiler’s absorption system. Clean packing has an improved ability to remove sulfur dioxide (S02) for reuse. Previously, the weak acid condensate was treated in the wastewater treatment system where it generated sludge due to its high biological oxygen demand. The new system doesn’t generate waste and increases the amount of SO2 captured for reuse.

0 Reduced chlorine additions by 32 percent by improving dose and mixing control andusing multi-point injection.

0 Installed a screw press to improve sludge dewatering. This increased capture ofbiological solids to 94-97 percent and lowered bio-solids emission to 3 0-40 percent ofthe permitted values.

0 Implemented avent gas control project that takes emissions from the bleach plant and other process vents and uses them as make up air for the recovery boiler. This practice consumes the organic emissions, effectively destructing them. Any SO2 in the emissions will be captured for reuse in the recovery boiler’s absorption system.

12 Pollution Prevention Opportunities in the Forestry and Sulfite Pulp Processing Industries

Western Pulp - Port Alice, British Columbia Western Pulp has completed or is in the process of completing the following pollution prevention activities. These projects were selected from a broader list of facility changes (Western Pulp, 1993):

o Performed a pilot study on primary treatment wastewater from a clarifier and determined that aerobic secondary treatment would lowerBOD by up to 95 percent.

o Installed a sulfur spray burner, upgraded chillers, and a quench vessel to reduce SO2 emissions, as well as installed extensive SO2 sampling and monitoring equipment to facilitate early leak detection and repair.

o Installed a wire hog in the wood plant to convert bundle straps to recyclable material.

o Stopped production of an acetate product because it generated high BOD waste

Established storm water and leachate collection and treatment to prevent these wastes from migrating off-site untreated.

o Improved sulfur conveyors to reduce spills and set up spill protection measuresfor all systems.

Anticipates achieving dramatic particulate reductions by installing a system to dry hog fuel (wood waste) by August 1994, so that it burns more efficiently, and by putting a filter system onthe boiler.

Additional Pollution Prevention Opportunities The following projects were either discussed at the conference or have been implemented at other pulp mills in the United States or Canada.

Implementation of 100 percent water recycling in wood room.

o Extending delignification to enhance cellulose purity and reduce chlorine demand.

0 Develop and use a risk assessment tool for prioritizing pollution prevention projects that is acceptable to industry and government. This tool would provide a common basis for evaluation and improve communication.

o Implementing oxygen or hydrogen peroxide bleaching to replace chlorine compounds. This has proven feasibility for sulfite pulps, except those used in “dissolving pulp” applications.

Switch to water or oil-based defoamers, and pitch dispersants that are free of TCDD and TCDF precursors. This change yields cleaner pulp and improved wastewater sludge quality.

13 Pac$fic Northwest Pollution Prevention Research Center

o Prevent liquor releases through planning and maintenance, tank and sewer monitoring, regular inspection, and efficient spill response.

o Modify or replace closed screening and deknotting systems to recover and recycle black liquor, reducing chemical demand.

o Add more washing stages to brown stock washing units to reduce liquor loss. This modification improves washing efficiency and reduces wastewater load.

Pollution Prevention Research Opportunities for the Sulfite Pulping Process To date, pollution prevention research in the pulping industry has focused on the kraft process. Roundtable participants stressed the need for research to support and encourage pollution prevention in the sulfite pulping process, which is significantly different. The proposed projects are listed below.

o Evaluate kraft pollution prevention techniques, especially ash management opportunities, for applicability to sulfite mill operation.

o Continue to research chlorine and alternative bleaching processes for sulfite mills and characterize TCDD production for each method. Little plant modification is necessary to adopt totally chlorine-free bleaching processes in sulfite mills.

o Develop color control options for eMuent by developing a secondary market or treatment for waste liquor from the digestion process. This information is available for kraft mills but the research is still needed for sulfite’s digestion chemistry.

o Identify ways to use secondary bio-solids. Possible options include adding bio-solids to anaerobic digesters or dewatering and then burning them.

o Find new methods to control process gas odor. A possible option is feeding captured gas to boilers as air intake.

o Explore water recovery. Millar Western Pulp Ltd. opened a zero-effluent, 240,000 ton/year bleached chemi-thermomechanical pulp facility in 1992 at Meadow Lake in Saskatchewan, Canada (Evans, 1993; Fosberg, et al, 1992). All eMuent goes to a waste water treatment unit that uses advanced evaporatioddistillation technology to treat and return the water to the process. The process designmanager for Millar Western’s water recovery system suggests that a similar treatmenthecovery facility may be appropriate for sulfite mills.

14 Appendix A: Roundtable Attendees

Bob Chaney James Evensen (formerly with Mike Sims Idaho National Engineering Lab AlaskaPulp Corporation) Kenai PeninslaBorough M/S 2203 Louisiana Pacific EconomicDevelopment District P.O. Box 1625 P.O. BOX4000-98 1 10 S. Willow, Suite 106 Idaho Falls, ID 83415-4147 Hayden Lake, ID 83 83 5 Kenai, AK 9961 1-7744 (208) 526-2279 (208) 747-60 1 1 (907) 283-3335

Dale Colton Tim Gebhard Dick Smith Alaska Pulp Corporation P.O. Box 263 City& Borough of Sitka RowanBay Logging Sitka, AK 99835 Public Works P.O. Box RWB 304 Lake St. Sitka, AK 99835 Robert Goff Sitka, AK 99835 (907) 630-2001 ADEC/SERO (907) 747-5809 4 10 Willoughby St., Suite 105 Amy Crook Juneau, AK 99801-1795 Dick Stokes ADEC/SERO (907) 465-5337 ADEC/SERO 410 Willoughby St., Suite 105 410WilloughbySt., Suite 105 Juneau, AK 99801 Madeline Grulich Juneau, AK 99801 (907) 465-5354 PPRC (907) 465-5350 1326FifthAve., Suite 650 Jane Ebert Seattle, WA 98101 Jan Straley 3307 HPR (206) 223-1 151 P.O. Box 273 Sitka, AK 99835 Sitka, AK 99835 (907) 747-6587 Carl Johnson c\o JamesEvensen Tom Thorburn Larry Edwards LouisianaPacific Western Pulp P.O. Box 6001 P.O. BOX4000-98 Environmental Supervisor Sitka, AK 99835 Hayden Lake, ID 83 83 5 P.O. Box 2000 (907) 747-8996 Port Alice, British Columbia Kurt Korthals Canada VLN2NO Page Else AlaskaPulp Corporation (604) 284-7758 22 19 Sawmill Creek Hwy 4600 Sawmill CreekRd. Sitka, AK 99835 Sitka, AK 99835 David Wigglesworth (907) 747-7448 (907) 747-2225 ADEC Pollution Prevention Office Cheryl Pritchard 3601 C St., #1334 P.O. Box 6209 Anchorage, AK 99503 Sitka,AK 99835 (907) 563-6529 Appendix B: Additional Sources of Information

National Council ofthe Paper Industry for Air and StreamImprovement 260 Madison Ave. New York, NY 10016 (212) 532-9000

Washington State Department ofEcology wRRLC/SwRO Attn: Dee Williams Mail Stop LU- 11 Olympia, WA 98504-681 1 Dee Williams: (206) 586-3 5 18

Alaska Department ofEnvironmental Conservation SERO Amy Crook 41OWilloughby St., Suite 105 Juneau, AK 99801 Amy Crook: (907) 465-5354

Forest Service PacificNorthwestResearch Station 333 S.W. 1st Avenue P.O. Box3890,6thfloor Portland, OR 98208 Attn: Cindy Miner Cindy Miner: (503) 326-7135

Technical Association ofthe Pulp and Paper Industry P.O. Box 105113 Technology Park Atlanta, GA 30348-5 113 (404) 446- 1400

Northwest Pulp and Paper Association 1300 114thAve. S.E.,Suite 110 Bellevue, WA 98004 (206) 455-1323 Appendix B (continued)

Forest Products Research Society 2801 Marshall Court Madison, WI 53705-2295 (608) 23 1-1362 (will supply up to 200 literature citations for $50, no charge forunsuccesskl searches)

Western Wood Products Association YeonBuilding 522 S.W. 5th Ave. Portland, OR 97204-2 122 (503) 224-3930

WashingtonPulp and Paper Foundation:

Dr. Donald Root University ofWashington Seattle, WA 98 195 Dr. Root: (206) 543-2764

Dr. Alton Campbell University ofIdaho Moscow, ID 83843 Dr. Campbell: (208) 885-7094 (Dr. Campbell is agood source of information in the area of ash-reutilization)

PollutionPrevention Information Clearinghouse US EPA, PM 21 1-A 401 M Street, S.W. Washington, D.C. 20460 (202) 260- 1023

Weyerhaeuser Attn: Environmental Affairs Tacoma, WA 98477 (206) 924-2345

Fletcher Challenge Canada 9th Floor 700 W. Georgia Box 10058 Pacific Center Vancouver, British Columbia Canada V7Y 157 (604) 654-4000 Appendix B (continued)

James River P.O. Box 875 Redmond, WA 98073 (206) 88 1-6000

Boise Cascade 4302 Chambers Creek Rd. Steilacoom, WA 98388 (206) 588-21 15

Scott Paper P.O. Box 925 Everett, WA 98206 (206) 259-7333 Appendix C: Bibliography

Alaska Department of Natural Resources (ADNR).Forest Resources and Practices Act. 1990

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