Use of nitrogen from an air separation unit as gas turbine air compressor feed refrigerant to improve power output

Abstract

The present invention is an improvement to a process for the production of work to generate electricity or to drive a mechanical device using a gas turbine. In the process, feed air stream is compressed and combusted with a fuel gas to produce a combustion product. This combustion product is expanded in a gas turbine expander, thereby producing a hot exhaust gas and work. This produced work is used to generate electricity or to drive a mechanical device. The improvement to the process, which increases the work produced by the gas turbine expander, is characterized by cooling nitrogen product, produced by a cryogenic air separation unit to a subambient temperature and combining this subambient cooled, nitrogen product with the feed air stream prior to compression. The improvement of the present invention is particularly suited to the process, wherein at least a portion of the oxygen product produced by the cryogenic air separation unit is reacted with a carbonaceous feedstock in a gasification unit to produce the fuel gas, which is rich in carbon monoxide and hydrogen. The carbonaceous feedstock reacted in the gasifier unit can be coal, petroleum coke, tar sands bitumen, tar sand emulsion, municipal wastes, petroleum residua, waste oil or mixtures thereof.

Dependencies are inferred from the claim text.