1 MEMORANDUM | 26 October 2012

TO Tab Tesnau, US EPA ORCR

FROM Jason Price, Wiles Kase, and Eric Reker, Industrial Economics, Incorporated

SUBJECT Generation, Management, and Pro cessing of Paper Processing Residuals

Pursuant to Technical Directive 1 issued under Work Assignment B-01, this memo
summarizes information that IEc obtained on the generation and management of paper processing residuals (PPRs). Based on our re view of the relevant literature and our contacts with industry representatives, th is memo presents the following data:

 The quantity of paper processing residuals generated on an annual basis in the
U.S.

 The portion of paper processing residua ls burned as an energy source, distinguishing between onsite use and offsite use.

 The quantity of paper processing residuals managed through other (non-fuel) end uses such as land application and landfilling.

 The type and level of processing for paper processing residuals used as fuel.

We obtained information on the generation and use of paper processing residuals from representatives of the American Forest & Pa per Association (AF&PA) and the Recycled Paperboard Technical Association (RPTA). 1 Based on an informal survey of their member companies, these representatives pr ovided the following information with respect to the generation and use of paper processing residuals:

 Generation of paper processing residuals: Paper recycling facilities generate between 450,000 and 600,000 tons of PPRs (including old corrugated cardboard) per year (although these data are not for th e most recent year and the amounts are likely to have changed with the increase in recycling). These values reflect the residuals generated by the initial screen ing process (i.e., to remove metals), materials that do not break down during processing (e.g., paper treated to repel water), and fibers too small to be re-u sed. There are no definitive data on what portion of this material is old corrugate d cardboard, but a broad array of types of recovered fiber, such as old magazines, old newsprint and office paper, are increasingly used at paper recycling mills as recovery rates approach 70 percent of all paper produced.

1 The information provided in this sectio n is based on personal communication with Tim Hunt of the AF&PA and Amy Schaffer of the RPTA, October 19, 2012. BACKGROUND

GENERATION AND USE

OF PAPER PROCESSING

RESIDUALS2  End uses: Roughly 30 percent of paper processing residuals (approximately 135,000 to 180,000 tons) are burned for their fuel value. Between six and ten companies currently burn paper processing residuals in 15 to 20 different mills. At mills that burn paper processing residuals as a fuel onsite, the percentage of this material burned ranges from 55 to 100 percent of the PPRs generated onsite. In addition, at some mills, paper pro cessing residuals provide up to 20 to 25 percent of the total solid fuel energy consumed onsite. Thus, paper processing residuals represent a significant source of energy for these facilities. PPRs are not burned during solid fuel boiler downtime or when combustion conditions and fuel availability dictate a different mix of solid fuels to meet boiler performance characteristics. The 70 percent of PPRs that are not burned for energy are mostly landfilled, with minimal amounts used for land applications.

 On-site versus off-site usage: Of the roughly 30 percent of PPRs burned as a fuel, a large majority is burned on site. The representative from the AF&PA estimates that no more than 5 percent of PPRs are burned offsite. As noted above, only 15-20 of the 100+ paper mills across the U.S. burn PPRs as fuel. Many facilities (particularly recycle mills) use natural gas in their boilers and are unable to use solid material as a fuel source. Unless an arrangement can be made
with another boiler in the area to use th e material, the PPRs generated at facilities that use natural gas boilers are landfilled.

IEc reviewed several sources related to th e nature and extent of processing that is regularly performed on PPR prior to use as a fuel, including public comments submitted to the EPA under the NHSM Rule, journal ar ticles, and industry websites. Excluding public comments on the NHSM rule, limited in formation was readily available on the subject, primarily focusing on paper processi ng in Europe and the United Kingdom. We were able to obtain one peer reviewed journa l article on the subject, which did not contain information on PPR processing in the US. Howeve r, the information in this article, which focuses on processing in Europe, describes pro cessing measures for PPR similar to those found in the public comments. In conduc ting this research, we identified processing information for both recycling process residuals and pulp & paper sludge, which are
defined as follows:

 Recycling process residuals (RPR) : paper fiber that is unusable (due to impurities, fibers too small for recyclin g process) resulting from the recycling

process.

 Pulp and paper sludge (PPS) : pulp and paper wastewater treatment

residuals.

To summarize, various methods are used to dewater and appropriately size PPR for use as fuel. PPS generally requires more intensive pr ocessing than RPR, particularly dewatering.

RECYCLING PROCESS RESIDUALS According to the public comment submitte d to the EPA under the NHSM Rule Package by nine major industry representatives, including the AF&PA, the American Wood Council, and the Biomass Power Association, some processing occurs before burning PROCESSING OF PAPER

PROCESSING RESIDUALS3 RPR for energy. 2 Processors generally use a slotted sc reen to select cellulosic fibers that are too small for paper production, which are c onsidered to have adequate heating value. Some plants will then use hydraulic presses to squeeze unwanted moisture out of the residuals before shredding the material to the optimal size for combustion. 3

The measures for processing of RPR described in AF&PA’s comment are corroborated in
the literature we were able to obtain. The litera ture states that to select the fibers too small for paper production or the recycling process, plants use a slot screening mechanism. 4 Infrequently, some plants may apply a dryi ng process to these residuals before firing them, but the minimal processing needed to conve rt these materials into valuable fuel is generally an attractive feature. 5

PULP AND PAPER SLUDGE (PPS) Information submitted in the public comment from AF&PA mentioned above indicates that significantly more processing is requir ed before PPS can be used as a fuel. The overwhelming majority of pulp and paper m ills remove water from PPS prior to use as a fuel (or in other applications), using belt and screw presses, steam heated filter presses, and sometimes steam heated rotary driers for additional dewatering. 6 Information submitted by one mill describes the processing of PPS in its plant:

“Process waters carry the fibers rejected by the screens and cleaners and the fines to the water treatment system. Gravity settli ng in the primary clarifier removes the solids from the process water. The settled solids, called clarifier WWTR, are pumped from the clarifier to the filter press. Wat er is squeezed out of the WWTR and it is hauled to the fuel pile for the multi-fuel boiler .” 7

Another mill process is as follows:

“ The mill generates combined primary and secondary WWTR using three parallel rotary screen thickeners (RSTs) followe d by screw presses. The RSTs and screw presses are optimized to provide the highest possible solids content. The dewatered WWTR is stored on a pad, then transferred to the boiler fuel reclaim area, and

2 American Forest & Paper Association, et al. , public comments submitted on the Rule to Categorize Non-Hazardous Secondary Materials That Are Solid Waste (EPA-HQ-RCRA- 2008-0329) and Co mmercial and Industrial Solid Waste Incineration Units: Reconsideration and Proposed Amendments (EPA -HQ-OAR-2003-0119). Comment ID EPA-HQ-RCRA-2008-0329-1946-A1. February 21, 2012. P. 55. 3 American Forest & Paper Association, et al. , public comments submitted on the Rule to Categorize Non-Hazardous Secondary Materials That Are Solid Waste (EPA-HQ-RCRA- 2008-0329) and Co mmercial and Industrial Solid Waste Incineration Units: Reconsideration and Proposed Amendments (EPA -HQ-OAR-2003-0119). Comment ID EPA-HQ-RCRA-2008-0329-1946-A1. February 21, 2012. P. 55. 4 Gavrilescu, D. “Energy from bi omass in pulp and paper mills.” Environmental Engineering and Management Journal , Vol. 7, No. 5, 537-546. September/ October 2008. P. 540. 5 Gavrilescu, D. “Energy from bi omass in pulp and paper mills.” Environmental Engineering and Management Journal , Vol. 7, No. 5, 537-546. September/ October 2008. P. 542. 6 American Forest & Paper Association, et al. , public comments submitted on the Rule to Categorize Non-Hazardous Secondary Materials That Are Solid Waste (EPA-HQ-RCRA- 2008-0329) and Co mmercial and Industrial Solid Waste Incineration Units: Reconsideration and Proposed Amendments (EPA -HQ-OAR-2003-0119). Comment ID EPA-HQ-RCRA-2008-0329-1946-A1. February 21, 2012. P. 53. 7 American Forest & Paper Association, et al. , public comments submitted on the Rule to Categorize Non-Hazardous Secondary Materials That Are Solid Waste (EPA-HQ-RCRA- 2008-0329) and Co mmercial and Industrial Solid Waste Incineration Units: Reconsideration and Proposed Amendments (EPA -HQ-OAR-2003-0119). Comment ID EPA-HQ-RCRA-2008-0329-1946-A1. February 21, 2012. P. 48.4 transported to the fluidized bed boiler, along with hog fuel, on a series of

conveyors. ” 8

In their public comment submitted to the EPA under the NHSM Rule Package, Verso Paper Corp. states that they employ an activated sludge treatment (AST) process and secondary holding tanks to separate out cellulo sic fibers from wastewater. According to
the comment:

“ After excess secondary sludge is removed fr om the treatment loop, at three of Verso’s mills it is mixed with primary sludge in blend tanks prior to being dried on belt presses to a suitable moisture level for burning or other uses. Sludge is introduced into the mills’ solid fuel feed systems by means of conveyers, where it becomes thoroughly mixed with other fuel s in the conveyer systems before being
introduced into the mills’ combination boil ers. At one mill, primary sludge is dried separately by means of screw presses, wh ile secondary sludge is dried using a belt press. The two fuels are fed separately by conveyers onto the mill’s main solid fuel conveyer, which transports the bark/sludge mi xture to a surge bin. The fuel is passed through a “waste heat dryer,” where it is briefly exposed to boiler flue gas before being fed into the combination boiler.” 9

As with RPR, the literature we were able to obtain corroborates the description of the level and type of processing of PPS provided in public comments. Gavrilecu (2008) states that maximum mechanical dewatering of sludge prior to combustion is essential. The paper also claims that recyclers and paper processors may mix PPS with dryer secondary materials to improve energy output. 10 Increasingly, PPS will undergo fluidized bed combustion, as it works particularly well with the wet sludge produced in de-inking mills. Gavrilescu states that, “in this process, air is bubbled through a bed of inert material (usually sand or limestone), which greatly improves the combustion process.” 11 Plants use varying processing methods for each type of PPS produced in “the common effluent treatment processes” (de-inking sludge vs. sludge from paper mill waste-water treatment plants, effluent sludge, etc.). 12

8 American Forest & Paper Association, et al. , public comments submitted on the Rule to Categorize Non-Hazardous Secondary Materials That Are Solid Waste (EPA-HQ-RCRA- 2008-0329) and Co mmercial and Industrial Solid Waste Incineration Units: Reconsideration and Proposed Amendments (EPA -HQ-OAR-2003-0119). Comment ID EPA-HQ-RCRA-2008-0329-1946-A1. February 21, 2012. P. 48. 9 Verso Paper Corp., public comments subm itted on the Rule to Categorize Non-Ha zardous Secondary Mate rials That Are Solid Waste (EPA-HQ-RCRA-2008- 0329) and Comme rcial and Industrial Solid Waste Inci neration Units: Re consideration and Proposed Amendments (EPA-HQ-OAR-2003-0119); and National Emission Standards for Hazardou s Air Pollutants for Major Sources: Industrial, Commercial, and Institutional Boilers and Process Heaters: Reconsiderat ion and Proposed Amendments (EPA-HQ-OAR-2002-0058). Comment ID EPA-HQ-RCRA- 2008-0329-1942. February 20, 2012. P. 6-7. 10

Gavrilescu, D. “Energy from bi omass in pulp and paper mills.” Environmental Engineering and Management Journal , Vol. 7, No. 5, 537-546. Septembe r/October 2008. P. 541. 11 Gavrilescu, D. “Energy from biom ass in pulp and paper mills.” Environmental Engineering and Management Journal , Vol. 7, No. 5, 537-546. Septembe r/October 2008. P. 541. 12

Gavrilescu, D. “Energy from bi omass in pulp and paper mills.” Environmental Engineering and Management Journal , Vol. 7, No. 5, 537-546. Septem ber/October 2008. P. 542.