David H. Archer

what's new in high temperature sulfur removal systems for fluidized-bed coal gasification

High temperature sulfur removal can be achieved with calcium-based sor-bents (e.g. dolomite) in fluidized-bed coal gasification systems now being developed for power generation. The use of dolomite offers the opportunity to meet environmental emission standards, to minimize energy losses, and to reduce electrical energy costs. In addition to removing sulfur from the low-Btu gas, the complete sulfur removal system must be integrated with the total power plant and environment to assure compatibility. Critical requirements for achieving commercial system include establishing criteria for ‘acceptable’ sorbents, establishing integrated sulfur removal/gasification process design parameters, predicting trace element release, predicting sorbent attrition, developing an economic regeneration and/or once through process option, developing a spent sorbent processing system, and establishing safe and reliable disposition options for spent sorbent. Design and operating parameters are being developed and potential proc...

Assessment of Fluidized Bed Oil Gasification for Power Generation

Fluidized bed gasification of high sulfur oil at atmospheric pressure for the production of a clean fuel gas has been evaluated technically and economically. The clean fuel gas with minimal sulfur and particulates is utilized for power generation in conventional fossil fuel fired boilers. The gasification occurs in g limestone bed. Hydrogen sulfide produced during the cracking and partial combustion of the oil is removed by the lime to yield a clean fuel gas and sulfided lime. The hot, low sulfur, low Btu, fuel gas is burned in a steam generator. The process can be operated as a once-through, throw-away limestone system or as a limestone regeneration/sulfur recovery system. The sulfided lime can be converted to calcium sulfate in an air-fluidized vessel, operating near 1500°F, for dry disposal in the once-through concept. The regeneration system converts the sulfur in the stone to SO2 in an air fluidized bed operating near 1900°F. The regenerated stone is circulated back to the gasifler and the SO2 rich s...