Dry Scrubbing for High-Sulfur-Coal Utilization

摘要

Three years ago, Argonne National Laboratory received a coal conversion order for its baseload boiler from the US Department of Energy (DOE). This order involved the reconversion of a 170,000-lb/hr gas-fired boiler back to spreader-stoker coal combustion. Argonne had decided, for this converison, to fuel the boiler with the high-Btu, high-sulfur coal typically found in the Illinois coal basin. In order to comply with the State of Illinois air-pollution emission regulations, it was necessary to install both particulate-matter and sulfur dioxide removal equipment. After studying both conventional and advanced technologies, Argonne decided to install the relatively new dry scrubbing process, even though it had never been tested on flue gas from high-sulfur-coal combustion. Argonne has had a high-sulfur dry FGC system in operation for the last two years. We have: (1) successfully demonstrated that reliable, economical removal of sulfur dioxide at and above the levels dictated by the NSPS is possible; (2) shown that a lime-based spray dryer can perform successfully in a retrofit mode, removing 70% of the inlet SO sub 2 ; (3) ascertained (from actual operation) that system economics seem to be in line with published estimates; and (4) found from waste studies that there is a dependence of pH upon leachate concentration (but no concentration of elements was high enough to classify wastes from a dry scrubbing system as hazardous). 3 references, 7 figures, 4 tables. (ERA citation 09:035083)