Materials Characterization Paper 

In Support of the 

Final Rulemaking: 

Identification of Nonhazardous Secondary Materials That Are Solid Waste 

Purification Process Byproducts 

February 3, 2011 

===================================================================== 

1. Definition of Purification Process Byproducts 

Purification process byproducts are residual materials generated from production processes to 

isolate specific chemicals or compounds. These secondary materials are made up largely of 

organic compounds that have a high molecular weight but are only somewhat volatile. Due to 

these characteristics, purification process byproducts are combustible but generally not 

flammable (Raiders et al. 2009). Purification process byproducts may be generated from several 

different processes, including distillation, extraction, and evaporation (EIA 2000). This analysis 

addresses only purification process byproducts that: 1) have potential fuel value or can be reused, and 2) are not considered hazardous under RCRA. 

2. Annual Quantities of Purification Process Byproducts Generated and Used 

(1) Sectors that generate purification process byproducts: 

• Purification process byproducts are generated from a variety of purification 

processes used by a number of industries. Such processes are employed in the 

production of processed food, beverages, petroleum products, chemicals, and 

several other products. Industries that generate these materials include the 

following, listed by NAICS code: 

o 311: Food Manufacturing 

o 312: Food and Beverage Manufacturing 

o 324: Petroleum Products Manufacturing 

o 325: Chemical Manufacturing (Census Bureau 2009). 

This list of industries is not necessarily exhaustive, given that purification process 

byproducts are generated by a wide range of processes used in the production of a 

variety of goods. 

(2) Quantities and prices of purification process byproducts generated: 

• Due to the wide variety of purification process byproducts generated, it is difficult 

to characterize the quantity or prices of purification process byproducts generated 

in the U.S. Overall, U.S. industrial facilities generate approximately 7.6 billion 

tons of non-hazardous industrial solid waste each year, which suggests that these 

facilities generate less than 7.6 billion tons of purification process byproducts on 

an annual basis (EPA 2008). 
Purification Process Byproducts 

2

• As indicated above, the petroleum products sector is among the many industries 

that generate purification process byproducts. While comprehensive information 

on the generation and management of the industry’s purification process 

byproducts has not been identified, EPA conducted a survey in 1996 to evaluate 

the management of 15 petroleum refining residuals that the Agency was 

considering to list as hazardous wastes at the time. Exhibit 1 summarizes findings 

from the Agency’s survey. 

Exhibit 1: Management of Select Petroleum Refinery Residues 

Management Practice Percentage 

Total Disposed 29.69% 

Off-site Landfill 24.92% 

On-site Landfill 3.88% 

Other Disposal Onsite/Roadbed mixing 0.14% 

Other 0.74% 

Total Discharged 14.42% 

Onsite Wastewater Treatment Facility 1.46% 

POTW 0.58% 

Surface Water (under NPDES) 10.99% 

Offsite POTW 1.39% 

Total Recovered, Recycled, Reused, Regenerated 27.21% 

Metal Catalyst Reclamation/Regeneration 16.72% 

Recycle to Processes (e.g., onsite recovery) 8.58% 

Miscellaneous Onsite Recycling 1.92% 

Total Stored 0.16% 

Total Stored in Piles 0.16% 

Total Transferred 10.30% 

Transferred to Another Refinery 2.69% 

Transferred for Direct Use as a Fuel or to Make Fuel 2.46% 

Transfer with Coke Product or Other Refinery Product 3.33% 

Other 1.82% 

Total Treated 18.21% 

Neutralization 10.12% 

Onsite Boiler 2.33% 

Onsite Industrial Furnace 2.91% 

Onsite Land Treatment 2.51% 

Other 0.35% 

Grand Total 100.00% 

 (EPA 1996)

 
Purification Process Byproducts 

3

(3) Trends in generation of purification process byproducts: 

• Information on trends in the generation of purification process byproducts is 

difficult to assemble given the range of products and management options. It is 

likely, however, that such trends will closely track production in those industries 

that generate purification process byproducts. These production trends are likely 

to vary by industry. 

3. Uses of Purification Process Byproducts 

(1) Combustion uses of purification process byproducts: 

• Purification process byproducts with sufficient calorific value can potentially be 

used as fuels in boilers, furnaces, and kilns. However, the combustion uses are 

likely to vary depending on the source of the residue. 

(2) Non-combustion uses of purification process byproducts:

• Comprehensive information on non-combustion uses for purification process 

byproducts has not been identified. The usability of these materials for noncombustion applications, however, is likely to vary across different purification 

process byproducts and non-combustion use applications.

4. Management and Combustion Processes 

(1) Types of units using purification process byproducts

• Information on the types of units using purification process byproducts has not 

been identified, but industrial residues in general are used in a variety of 

combustion units, including liquid-fueled boilers and process heaters. (EPA 

2004). 

(2) Sourcing of purification process byproducts:

• Purification process byproducts originate at many different types of facilities 

(Raiders 2009). No information, however, has been identified on the collection 

and distribution of these materials. 

(3) Processing of purification process byproducts: 

• Information on the processing of purification process prior to their use has not 

been identified. It is likely, however, that processing requirements would vary 

across beneficial use applications and purification byproducts. 

(4) State regulatory status of purification process byproducts use: 

• At this stage, we have not identified any states that have specifically granted a 

beneficial use designation for the use of purification process byproducts as fuel, 

but we have not performed an exhaustive investigation of state activities and 

regulations. 
Purification Process Byproducts 

4

5. Commodity Composition and Impacts 

(1) Composition of purification process byproducts: 

• The composition of purification process byproducts can vary across specific 

byproducts. As indicated above, however, they are typically high in organics, 

which makes them a useful non-hazardous fuel source (Raiders et al. 2009). The 

concentrations of other constituents are difficult to characterize because they 

depend on the specific purification process from which the material was 

generated. 

(2) Impacts of purification process byproduct use:

• Benefits associated with the use of purification process byproducts as fuel include 

avoided risks associated with disposal, cost savings associated with avoided 

disposal and recovery of energy, and the avoided environmental impacts 

associated with production of energy from “virgin” non-renewable sources when 

purification process byproducts are used instead. 

• The specific lifecycle impacts of purification process byproducts used as a fuel 

are not evaluated here because of uncertainties in lifecycle scenario development. 

For example, it is difficult to identify the fuel (Btu) value and emissions factors 

associated with a “typical” non-hazardous purification process byproduct that is 

suitable for fuel. In addition, purification process byproducts may substitute for a 

variety of fuels; the choice of fuel often depends on location specific-factors such 

as the location of the combustor in relation to fuel supplies, and on the design of 

the specific combustion unit. Avoided upstream impacts depend heavily on the 

specific fuel being displaced in the lifecycle scenario. 
Purification Process Byproducts 

5

References 

Raiders, Richard and Lew Buchanan, public comment in response to EPA’s Advanced Notice of Proposed 

Rulemaking for Identification of Non-Hazardous Materials That Are Solid Waste, EPA docket EPA-HQRCRA-2008-0329, submitted on behalf of Arkema, Inc., February 2, 2009. 

United States Census Bureau. 2008, “2007 NAICS Codes and Titles,” accessed April 16, 2009 at: 

http://www.census.gov/cgi-bin/sssd/naics/naicsrch?chart=2007 

United States Energy Information Administration (EIA). 2000, “Chemical Industry Analysis Brief: Technologies 

and Equipment,” accessed April 21, 2009 at: 

http://www.eia.doe.gov/emeu/mecs/iab/chemicals/page4.html 

United States Environmental Protection Agency (EPA). 2008, “Guide for Industrial Waste Management.” Accessed 

on April 19, 2009 at: http://www.epa.gov/epawaste/nonhaz/industrial/guide/index.htm 

United States Environmental Protection Agency (EPA). 2004, “Regulatory Impact Analysis for the Industrial 

Boilers and Process Heaters NESHAP. 

United States Environmental Protection Agency (EPA). 1996. “Study of Selected Petroleum Refining Residuals.” 

Accessed on April 21, 2009 at 

http://www.epa.gov/osw/hazard/wastetypes/wasteid/petroleum/study_p1.pdf.