Application analysis of layered pressure swing adsorption method for offshore floating natural gas purification

In view of the particularity of offshore operations, a new layered pressure swing adsorption (PSA) method for natural gas purification was proposed. CH4 is enriched in the three-component CH4/CO2/N2 crude mixed gas. The pressure swing adsorption process is based on the traditional method. The adsorption bed is divided into two layers, which are the first layer with activated carbon as the adsorbent to remove CO2 impurities, and the second layer with molecular sieve as adsorbent to remove N2 impurities. The process of PSA was simulated by Aspen Adsorption software. The simulation results show that after the process of double layered PSA, the purity of the product gas CH4 reached 98.7%, and the recovery rate of gas production was 89%. The concentration of CO2 was successfully reduced to 0.23% in the activated carbon layer, and the concentration of N2 was reduced to 1.2% in the molecular sieve layer of the first Tower.