MANAGEMENT OF BYPRODUCTSOLIDS GENERATED IN THEPULP AND PAPER INDUSTRYBill ThackerNCASIPresentation to EPA OSW StaffWashington, DCJanuary 23, 2007Presentation Coverage•Brief introduction to the U. S. pulp and paper industry•Review of the generation, characteristics, andmanagement of byproduct solids•Presentation of two brief case studies•Discussion limited to·Wastewater treatment plant (WWTP)residuals (“sludge”)·Boiler ashU.S. Pulp and Paper Industry430 Pulp & paper mills•National annual production: 100 million tons of paper,paperboard, and market pulp•Top 10 states (yr 2000):GA AL LA WA WIMI SC ME OR VA•Variety of manufacturing processes, mill capacities, andend productsByproduct Generation•Annual generation of solid wastes or byproduct solids:15 million dry tons•Including·Wastewater treatment plant (WWTP) residuals·Boiler ash(also flue gas desulfurization material)·Causticizing residues·Wood yard debris·Pulping and papermaking rejectsWWTP Residuals•5.5 million dry tons annually•Types·Primary (including deinking residuals)·Secondary (waste activated sludge)·Combined primary and secondary·Dredged•Mechanical dewatering is the norm,with solids content typically 30-40%,range 20-60%•Small number of mills dry residuals (70-95% solids)Characteristics of WWTP Residuals•Primary WWTP residuals consist mainly of·Wood fiber·Inorganic or mineral matter (e.g., clay, CaCO3, TiO2)•“Ash”(inorganic)content of primary WWTP residuals rangesfrom <10% to >70%(dry wt. basis)•Secondary WWTP residuals consist mostly of bacterialbiomass (non-pathogenic)Burned21.9%Other BeneficialUse11.7%Landfill/Lagoon51.8%Land Application14.6%Management of WWTP Residuals2002 data(AF&PA)Management of WWTP Residuals•Land application·Utility:soil conditioner, fertilizer, liming agent, mulch·Potential issue: high C:N ratio(quite high for primary residuals)•Burning(usually onsite)·Utility: energy,volume reduction·Potential issues: high moisturehigh “ash”Other Uses for WWTP Residuals•Papermaking fiber/filler•Industrial absorbent•Animal bedding/litter•Manufactured soil component•Compost feedstock•Landfill barrier cover•AMD* control cover•Building board/fixture•Brick or concrete additive•Glass or lightweight aggregate•Cement kiln feedstock•Fuel pellet ingredient* Acid mine drainageWWTP Residuals Case Study•Startup company in the Northwest began manufacturingresiduals-based products forconsumer, agricultural, andindustrial markets in 1986•Technical and marketing challenges resulted in 12 yearsof effort before first profit realized•Major products currently are·Small-animal bedding·Cat litter·Oil-spill & general industrial absorbentsWWTP Residuals Case Study•Products available in 16 countries•Bedding & litter available in major U.S. pet store anddepartment store chains•Recently built a 2ndmanufacturing plant in the Southeastto better serve Eastern U.S. and began product shipmentsin December 2004Boiler Ash•4 million dry tons annually•Types(based on fuel)·Wood·Coal·Wood and coal·Wood, coal, or both with miscellaneous solid fuels•Wood ash·High in unburned carbon (char)·High in Ca, source of K and P·Alkaline·CementitiousOther BeneficialUse25.3%Landfill/Lagoon65.4%Land Application9.3%Management of Boiler Ash2002 data(AF&PA)Management of Boiler Ash•Land application·Utility: liming agent,fertilizer·Potential issue: unburned carbon (wood ash)Other Uses for Boiler Ash•Compost feedstock•Manufactured soil component•Cement kiln feedstock•Concrete additive•Flowable fill (CLSM)*•Waste stabilization•Soil stabilization•Earthen construction•Asphalt aggregate•Landfill daily cover* CLSM = controlled low-strength materialBoiler Ash Case Study•Southeastern mill had its coal fly ash used as concreteingredient for highway & other applications•State DEP approved injecting wood ash into coal boiler (toobtain more energy and lower ash loss-on-ignition)•State DOT approved use of coal-wood fly ash in concreteafter short-term and long-term (>3 yrs) testing•With coal-wood fly ash added, concrete is·Stronger and more durable·More resistant to water erosion (saltwater use)·Less expensive•Coal-wood bottom ash employed as aggregate in asphaltmixes and in concrete blocksSummary•Two significant byproducts from the paper industryare WWTP residuals and boiler ash•Land application is an important beneficial use forboth types of materials•There are numerous examples of other uses•Paper companies continue to seek beneficial useopportunities and increasingly explore novel usesQuestions & CommentsBill ThackerNCASI269-276-3548william.thacker@wmich.eduwww.ncasi.org