REFRIGERATION FROM EXPANSION OF TRANSMISSION PIPELINE GAS

摘要

Refrigeration is produced while delivering transmission pipeline gas (20) of elevated pressure to a branch pipeline of lower pressure by expanding the gas in a turbo-expander (29) to a pressure below the branch pipeline (47) pressure and recovering refrigeration from the expanded gas which is then compressed by a centrifugal compressor (41) directly driven by the turbo-expander (29) to the pressure required for delivery into the branch pipeline (47). The gas (20) is dehydrated by adding methanol through pump (24), and separating aqueous methanol condensate from the expanded gas in separator (31), and the condensate is distilled in column (55) with compression heat in reboiler (64) to recover methanol for reuse.