Study On Separating Carbon Monoxide From Syngas By Pressure Swing Adsorption

Carbon monoxide has been widely used in C1-Chemistry as raw materials, but it is also a kind of harmful contamination to atmosphere and can cause catalyst poisoning. So the separation and recovery of the gas has become a very important task. Pressure Swing Adsorption (PSA) is an effective method for separating CO from gas mixtures for its easier operation and lower energy demanded. Nowadays, the study on adsorbents is concentrating on cuprous salt as an active component loaded on a carrier. The adsorbent used in this paper was composed by rare earth with Cu(I) supported on activated carbon. We called the NA adsorbent that has a satisfactory selectivity for CO. For recycling CO and attaining high-purity CO, adsorption of gas mixture containing CO on NA adsorbate under dynamic conditions was studied. For puritying syngas for synthetic ammionia, PSA of CO with low concentration was investigated. The energy demanded of removal CO with PSA process and methanation were also compared.Static and dynamic adsorption behaviors of carbon monoxide, nitrogen, methane and carbon dioxide were investigated. The dynamic separation systems researched included the mixtures of CO-N₂, CO-CH₄, CO-CO₂, CO-N₂-CH₄, CO-CH₄-CO₂. The effect of trace O₂ on the dynamic adsorption of CO was studied. The results show that the NA adsorbent has a high CO adsorption capacity and a satisfactory selectivity for CO. The adsorbent was suitable for PSA. The separation coefficient of CO to N₂ is higher (>5.5) and only a small amounts of N₂ is adsorbed. The adsorbent can separate CO from CO-N₂ mixture efficiently. The separation coefficient of CO to CH₄ is inferior to the one of CO-N₂. The adsorptive capacity of CO₂ on NA adsorbent is higher than CH₄, but CO₂ has little influence on the dynamic adsorption of carbon monoxide. When gas mixture contains three adsorbable components, the selectivity for CO is slightly less than that of two components. The adsorption capacity of CO for the fresh adsorbent is the largest. Then it reduced to two third after vacuum...