Preparation of low-sulfur fuel gas for gasification of Battelle treated coal

Battelle's Columbus Laboratories has developed a proprietary process for treating coal with calcium compounds, called the Battelle Treated Coal process, in which the incorporated calcium produces an improved gasification feedstock. From the results of batch and continuous fixed-bed gasification testing of BTC the following conclusions were drawn: 1) 80-95% of the coal's sulfur can be captured in the coal ash, eliminating the need for gas desulfurization; 2) tar-free, very-low-oil fuel gas can be produced, greatly simplifying down-stream processing; 3) non-leachable sulfur containing ash, which can be disposed of in an environmentally acceptable manner, can be produced minimizing disposal problems; 4) a 185-200 Btu/SCF (including 175-190 Btu/SCF higher heating value plus sensible heat equivalent to at least 12 Btu/SCF) gas can be produced, minimizing boiler derating and retro-fitting problems; 5) mildly caking eastern coals can be rendered nonswelling and non-agglomerating, extending the range of coals acceptable for fixed-bed gasification; 6) the steam reactivity of BTC is greatly increased over the parent coal, which leads to increased gasifier throughput; 7) the ash-fusion temperatures are significantly increased compared to the raw coal, allowing higher temperature operation which produces less carbon dioxide, requires less steam, and minimizes potential clinkering and slagging problems; and 8)more » the hot fuel gas can be used directly, eliminating the need for cooling operations, increasing overall thermal efficiency, and eliminating the wastewater problem associated with treatment of the condensate collected from unreacted steam. 4 tables, 1 figure, 12 references« less