Patent ID: 9163188
Filing Date: 2015-10-20
Classification: B01D,C01B,C10K,F25J,Y02C,Y02P

Abstract:
1. A process for separating a synthesis gas stream containing hydrogen sulfide (H 2 S) impurities into a hydrogen (H 2 ) rich vapor stream ( 34 ) and a liquid carbon dioxide (CO 2 ) stream in a CO 2 condensation plant that comprises (a) a compression system comprising at least one compressor, (b) a heat exchanger system, (c) a gas-liquid separator vessel, (d) a turboexpansion system comprising a plurality of turboexpanders arranged in series and (e) an H 2 S recovery unit the process comprising the steps of: (A) feeding the synthesis gas stream at a pressure in the range of 10 to 60 barg to the compression system of the CO (B) cooling the HP synthesis gas stream formed in step (A) to a temperature in the range of −15 to −55° C. by passing the HP synthesis gas stream through the heat exchanger system in heat exchange relationship with a plurality of internal refrigerant streams wherein the internal refrigerant streams are selected from the group consisting of cold hydrogen rich vapour streams and liquid CO (C) passing the cooled HP synthesis gas stream formed in step (B) to a gas-liquid separator vessel that is operated at the same pressure as the heat exchanger system and withdrawing a high pressure (HP) hydrogen rich vapor stream from at or near the top of the separator vessel and a high pressure (HP) liquid CO (D) feeding the HP hydrogen rich vapor stream from step (C) to the turboexpansion system wherein the HP hydrogen rich vapor stream is subjected to isentropic expansion in each of the turboexpanders of the series such that hydrogen rich vapor streams are withdrawn from the turboexpanders of the series at reduced temperature and at successively reduced pressures and wherein isentropic expansion of the HP hydrogen rich vapor in each of the turboexpanders of the series is used to drive a compressor of the compression system and/or to drive a turbine of an electric generator and (E) passing the HP liquid CO