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Show emissions were higher than normal when deposits were being removed, and the severity of hysteresis was reduced after sootblowing. INTRODUCTION On May 6, 1987, the Environmental Protection Agency (EPA) proposed regulations for burning hazardous wastes in boilers. These proposals would bring boilers, which had previously been exempted, under Resource Conservation and Recovery Act provisions, 40 CFR part 260, et al. An important feature of the proposed regulations is that certain boilers, based on operating conditions, would be exempted from a trial burn that normally would be required to demonstrate OREs of 99.99 percent or more. Specifically, a boiler could be waived from a trial burn if the following operating conditions were met: • A minimum of 50 percent of the heat input to the boiler is from gas, oil, or coal. • The boiler load is at least 25 percent. • The cofired waste heating value is at least 8,000 Btu/lb. • The waste is fired with an atomizer. In addition, the flue gas carbon monoxide would generally be monitored continuously during cofiring, and cofiring would be curtailed if CO were greater than 100 ppm over any 60-minute period, or CO were greater than 500 ppm over any la-minute period. The basis for the proposed boiler cofiring standard, and particularly the trial burn waiver cited above, was largely the test data from a series of 14 industrial boiler cofiring field tests conducted by EPA from 1982 to 1986. These tests were run to determine the capabilities of industrial boilers for waste destruction under both well-controlled and routine operation. The boiler test facility specifications and operating conditions were selected to obtain a reasonable coverage of the diverse range of industrial boiler designs and operating practices. Field test data were obtained for the following range of conditions: • Firetube, package and field-erected watertube designs; 0.3 to greater than 2 seconds residence time in main firebox • 2,500 to 350,000 1b/hr steam capacity • Gas, oil, coal, and wood fuels • Volatile and semi volatile wastes with a heating value from a to 18,000 Btu/lb • 0 to 100 percent heat input from wastes The results of these 14 tests showed an overall mass-weighted waste destruction efficiency of 99.998 percent. This high level of destruction was generally exhibited across the broad range of designs, waste characteristics, 2 .. ) |
