AIR SEPARATION

摘要

Air is compressed in a compressor 32 and a first stream of the compressed air is separated in a plant 34 into oxygen and nitogren. A stream of the oxygen is reacted in a gasifier 22 with coal to form a reducing gas. The reducing gas is reacted with iron ore in a shaft furnace 24 to form molten iron and a residual fuel gas. The residual fuel gas is compressed in a compressor 40 and is combusted in a chamber 52. A second stream of the compressed air is used to support this combustion. The resulting combustion gases are expanded in a turbine 54 and useful work is recovered therefrom. A stream of nitrogen from the air separation plant 34 is heated in a heat exchanger 60 and expanded with the combustion gases in the turbine 54 or separately in a further turbine. The work recovered from the turbine (5) exceeds that expended in compressing the air.