Field Tests of Industrial Boilers Cofiring Hazardous Wastes

Abstract

Thirteen field emission tests have been performed on eight industrial boilers cofired with conventional fuels and hazardous wastes. The U.S. Environmental Protection Agency (EPA) sponsored the tests to evaluate the effectiveness of industrial boilers for hazardous waste thermal destruction while recovering useful energy. Five initial tests were made on a wide range of waste type/boiler design combinations to quantify emissions representative of current industry practices. For the second series of tests, boilers firing waste streams spiked with a mixture of carbon tetrachloride, chlorobenzene, and trichlorethylene were tested to extend the data base for chlorinated wastes and facilitate intrasource comparisons. Principal organic hazardous constituents (POHC's) in the flue gas were quantified using two extractive sampling trains. Volatile compounds were absorbed on two Tenax traps in the volatile organic sampling train (VOST). Semivolatile compounds were absorbed on XAD-2 sorbent in a modified Method 5 train. The sampling protocol also included continuous monitor measurement of stack O2, CO, CO2, NOX and total hydrocarbons; extractive train samples of HC1; and grab samples of the conventional and waste fuels and ash streams. Post-test analyses of the inlet fuels and the outlet stream samples were done with gas chromatography/mass spectrometry to quantify the destruction and removal efficiency of POHC's. Results for the thirteen tests are discussed in this paper. Specie destruction and removal efficiency (DRE) ranged from 99.5 to >99.999 percent. The mass weighted destruction efficiency for all RCRA Appendix VIII compounds was 99.998 percent. Products of incomplete combustion (PIC's) were observed in concentrations one order of magnitude greater than measured POHC breakthrough.