Study on the Separation and Purification Process of the Carbon Dioxide from the Biogas with Variable Pressure Adsorption

In this paper, we present a novel method to separate carbon dioxide, hydrogen sulfide and water vapor from biogas. natural biogas is consist of methane with a concentration about 60%, carbon dioxide which is about 40%, also a small mount of impurity inside such as hydrogen sulfide and water vapor etc. The separated carbon dioxide was purified, condensed for recycling purpose. Meanwhile, the biogas was also purified and condensed to increase the concentration of methane in the biogas for improving the calorific value of the biogas. In this way, the high quality and comprehensive utilization of the biogas will be realized. The results indicate that the biogas separating process is environmental friendly, energy saving and high efficiency. It is necessary for energy saving, high efficiency comprehensive utilization, clean renewable energy, carbon emissions reducing and the ecological environment protection.