SIMULTANEOUS HOT DESULFURIZATION AND IMPROVED FILTRATION IN COAL UTILIZATION PROCESSES

Much of America's vast coal reserves will remain unusable until techno logy capable of the effective, economic removal of particulate and sul filv emissions becomes more highly developed. Traditional calcium base d sorbents, as well as more novel metal oxide sorbents, such as zinc f errite and zinc titanate are effective in sulfur removal but can be co stly and do little to mitigate particulate within high temperature coa l combustion and gasification streams. An innovative approach involvin g the use of classified, spent metal oxides appears to be a promising resolution to the particulate and sulfur dilemmas associated with most coal utilization processes. A number of such waste metal oxides have been tested, to assess their capacity for sulfur capture in sulfur lad en oxidizing and reducing environments. Inert materials such as silica sand and traditional sorbents such as limestone and dolomite, were al so evaluated to serve as reference data. Experimentation proved that t he ''once-through'' spent metal oxide sorbents can effectively remove sulfur while simultaneously increasing the permeability of dust collec ted at downstream ceramic filter stations. Additionally, spent metal o xides are generated in large quantities as a result of metal processin g, smelting, and refining operations, and are generally available at l ittle or no charge, for use as cost effective sorbents in coal combust ion and gasification processes. This paper suggests the use of such sp ent metal oxides in place of calcium based or regenerable pelletized m etal oxide sorbents for the removal of sulfur dioxide (SO2) and hydrog en sulfide (H2S) from gas streams containing these components.