Emission Factors for Several Toxic Air Pollutants from Fluidized-Bed Combustion of Coal

摘要

Clean coal technologies such as fluidized-bed combustion have the potential to emit the same trace elements as conventional combustors. Since the US Environmental Protection Agency (EPA) is likely to promulgate National Emission Standards for Hazardous Air Pollutants for several trace elements, the feasibility of using fluidized-bed combustors to reduce sulfur dioxide emissions may depend in part on the relative amounts of trace elements emitted by fluidized-bed and conventional combustors. Emissions of trace elements from both atmospheric and pressurized fluidized-bed combustors were compared with those from conventional combustors by developing fluidized-bed emission factors from information available in the literature and comparing them with the emission factors for conventional combustors recommended in a literature search conducted for EPA. The comparisons are based on the mass of emission per unit of heat input for antimony, arsenic, beryllium, cadmium, chromium, cobalt, copper, lead, manganese, mercury, nickel, vanadium, and zinc. When inaccuracies in the data were taken into account, the trace element emissions from atmospheric fluidized-bed combustion seem to be somewhat higher than those from a conventional utility boiler burning pulverized coal and somewhat lower than those from pressurized fluidized-bed combustion. (ERA citation 12:022175)