High recovery process for purification of multicomponent gases

A cyclic pressure swing adsorption (PSA) process for the substantial removal of H2O and CO2 comprising:

• contacting a multicomponent feed gas at elevated pressure with an adsorbent bed wherein the adsorbent bed comprises a layer of activated alumina, a layer of silica gel, and a layer of alkali-promoted alumina to obtain a multicomponent product gas substantially free of H2O and CO2 with high recovery of the product gas components, the process wherein a plurality of adsorbent beds in a PSA system are subjected to a series of process steps which include an adsorption step, three or more pressure equalization steps at decreasing pressure, a blowdown step, a purge step in which a purge gas comprises a portion of the product gas or a gas originating externally from the process that is substantially free of H2O and CO2 and comprises at least one of the major components of the product gas, three or more pressure equalization steps at increasing pressure, and a final repressurization step, wherein each of the adsorbent beds contains at least one adsorbent layer for the substantial removal of CO2 characterized by:
• i.a CO2 loading capacity of greater than or equal to 0.1 mol CO2 per kg of adsorbent at a CO2 partial pressure of 1000 Pa at 300 K, and
• ii.a differential capacity of the product gas components of less than or equal to 0.1 mol per kg of adsorbent, where the differential capacity is defined as the difference between the loading capacity at partial pressures of 100,000 Pa and 10,000 Pa at 300 K;
• and wherein the high recovery of the product gas components is an amount greater than or equal to 80%, where recovery, Xi herein defined as the flow rate of each component in the product gas relative to the flow rate of each component in the feed gas and is expressed algebraically as:
• X
• i
• [
• %
• ]
• =
• F
• Product
• ·
• y
• Product
• i
• F
• Feed
• ·
• y
• Feed
• i
• ·
• 100
• ⁢
• %
• where:
• i:
• gas component index (H2, CO, CH4)
• Fproduct:
• flow rate of the product gas
• FFeed:
• flow rate of the feed gas
• y
• Product
• i
• :
• concentration of component i in the product gas
• y
• F
• ⁢
• e
• ⁢
• e
• ⁢
• d
• i
• :
• concentration of component i in the feed gas.