Air Pollution Technology

Robert E. Hall and Chun Wai Lee Combustion Research Branch Air and Energy Engineering Research Laboratory United States Environmental Protection Agency Research Triangle Park, NC 27711 Garth R. Hassel Energy and Environmental Research Corporation 18 Mason Irvine, CA 92718 Jeffrey V. Ryan Environmental Systems Division, Acurex Corporation 4915 Prospectus Drive Durham, NC 27713

Abstract
Bench-scale tests were performed to characterize the combustion emissions from chlorofluorocarbon (CFC-11 and -12) incineration. The destruction efficiencies (DEs) of the CFCs and the major products of incomplete combustion (PICs) from each CFC were determined. DEs of at least 99.999% can be attained repeatedly for both CFCs. Major PICs identified were non-halogenated, with toluene and xylene being found most frequently. PIC concentrations were independent of the CFC concentration in the fuel. Sampling was performed one time to screen for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs) and polyaromatic hydrocarbons (PAHs) while incinerating CFC-12. Even with a DE of greater than 99.999%, high levels of PCDDs/PCDFs were formed. The extensive PCDD/PCDF formation apparently occurred in the absence of entrained particulate matter.

Paper presented at 1992 International CFC and Halon Alternatives Conference, September 29 - October 1, 1992, Washington, DC.

Jeffrey V. Ryan Acurex Environmental Corporation 4915 Prospectus Drive P.O. Box 13109 Research Triangle Park, NC 27709 C. W. Lee Combustion Research Branch Air and Energy Engineering Research Laboratory U. S. Environmental Protection Agency Research Triangle Park, NC 27711 Steven Korn T-Thermal Inc. Brook Road Conshohocken, PA 19028

Abstract
As a result of the Montreal Protocol, an international accord implemented to reduce the production and use of stratospheric ozone depleting substances, considerable quantities of chlorofluorocarbons (CFCs) and halons may be accumulated and may ultimately require disposal or destruction. Incineration is a potential destruction technology; however, little is known of the combustion emissions characteristic from incinerated CFCs. A study has been performed that characterizes the organic emissions resulting from the pilot-scale incineration of trichlorofluoromethane (CFC-11) and dichlorodifluoromethane (CFC-12) under varied feed concentrations. A 290 kW (1,000,000 Btu/h) incinerator was made available to the U. S. Environmental Protection Agency (EPA) for these tests. The emissions characterizations focused on determining the destruction and removal efficiencies (DREs) and major products of incomplete combustion (PICs) for each CFC evaluated. Sampling was performed to screen for volatile and semivolatile organic emission products including chlorinated aliphatics, chlorobenzenes, chlorophenols, polychlorinated dibenzodioxins and furans (PCDDs and PCDFs), and polyaromatic hydrocarbons (PAHs). Results indicate that five nines (99.999 percent) DRE can be achieved at a CFC-11 feed concentration as high as 69 percent by mass. The formation of volatile and semivolatile organic PICs was minimal. "Less than" concentrations are presented for target analytes not detected. Total PCDD/PCDF emission concentrations did not exceed 140 ng/m³. The injection of water into the combustion zone may improve the thermal destruction process.

Paper presented at the 12th Annual Incineration Conference, May 3 - 7, 1993, Knoxville, TN.