Emissions R&D at GE/CRD coal-fueled diesel: Technology development methods for SO(sub 2) and NO(sub x) removal from coal diesel exhaust.

摘要

Four processes were investigated at the GE Research and Development Center (GE-CRD) for the removal of gaseous pollutants from the exhaust of a coal-fired diesel locomotive engine. The minimum goal for emissions control was to reduce the pollutant levels at least to the levels of a conventional diesel engine. It should be noted, however, that some of the methods investigated were capable of reducing emissions below these levels. Achieving the minimum goal requires a reduction of approximately 50% in SO(sub 2) emissions and a 90 to 95% reduction in particulate emissions, the actual percentages varying with the fuel. NO(sub x) emissions from the coal diesel are approximately 50% of the conventional diesel level. The space limitations on board the locomotive present the greatest obstacle to the design of an emissions control system. The cleanup system must be compact as well as multifunctional. The development of a particulate collection device was undertaken by GE Environmental Services, Inc. (GEESI). Among the options they evaluated were high-temperature metal filters, cyclones, and a granular bed. The development of a cleanup method or SO(sub 2) and possibly NO(sub x) was undertaken at GE-CRD. A process was sought which could incorporate one of the particulate removal devices under consideration. Four processes utilizing three classes of sorbents -- copper oxide, calcium-based, and sodium bicarbonate --were investigated for SO(sub 2) capture: Two of these processes use copper oxide (CuO), a regenerable SO(sub 2) sorbent. The CuSO(sub 4) formed has the added property that it catalyzes the reduction of NO(sub x) to N(sub 2) in the presence of NH(sub 3). This NO(sub x) removal capability was tested for both CuO processes.