Pressure swing absorption process for separation of a gas mixture

摘要

The pressure swing adsorption (PSA) gas separation process comprises delivery of adsorber residual gas to different pressure distribution pipes (50A, B) during different pressure stages of adsorber decompression/regeneration. The PSA gas mixture separation process comprises delivering residual gas from an adsorber (I, II, III, IV) to: (a) a first residual gas distribution pipe (50A) under a first distribution pressure during a first decompression/regeneration stage, in which the adsorber pressure is within a first intermediate pressure range between the high pressure (PM) and the low pressure (Pm) of the cycle; and (b) to a second residual gas distribution pipe (50B) under a lower second distribution pressure during a second decompression/regeneration stage, in which the adsorber pressure is within a second pressure range between the low pressure (PR) of the first pressure range and the low pressure (Pm) of the cycle. Independent claims are also included for the following: (i) a PSA gas separation unit for carrying out the above process, in which the inlet of each adsorber (I, II, III, IV) is connected via a respective valve (15A, 25A, 35A 45A; 15B, 25B, 35B, 45B) to the first and second residual gas distribution pipes (50A, 50B); and (ii) a petrochemical plant, especially for refining, comprising the above gas separation unit and a gas mixture producing unit which supplies gas to the separation unit and which is equipped with a burner module connected to the second residual gas distribution pipe (50B). Preferred Features: The first residual gas distribution pipe (50A) is connected to a first gas distribution network at 2-9 bars pressure, especially in a petrochemical plant, the first decompression/regeneration stage being an elution stage at a pressure equal to the first distribution pressure (PR). The second distribution pipe (50B) is connected to a second gas distribution network at 1-3 bars pressure or to a burner module operating at 1-2 bars pressure, the second decompression/regeneration stage being an elution stage at the low pressure (Pm) of the cycle equal to the second distribution pressure (PR). The gas mixture producing unit is a steam reforming, catalytic reforming or partial oxidation unit.