Technique Research On Fermentation And Puriifcation Of Biogas

With the development of the world economy, the price of fossil fuel is growing rapidly with the increasing of international energy demand, leading to the mounting economic operating cost and operational risks. The massive use of fossil fuel has caused ever-worsening environmental problems. In order to protect the environment, reduce carbon emissions and realize a diversified energy supply, countries all over the world have been paying more and more attention to the development of new energy. As a newly non-conventional energy resource, biogas engineering projects are on an unceasingly increase in numbers, because of the renewable and low carbon characteristics of biogas. It is necessary to strengthen the research of biogas fermentation, separation and purification technology, in order to further expand the applicable areas of biogas fermentation engineering, improve the utilization quality of methane and its fermentation by-products, so as to increase the overall economic efficiency and to reduce the comprehensive cost of biogas fermentation engineering.On the basis of characteristics of the mid-temperature fermentation of straw and the components of biogas, the fermentation process for mid-temperature methane tank and the separation and purification technique of pressure swing adsorption are systematically studied. A fermentation tank system which is suitable for straw is designed based on the characteristics of straw fermentation, after having taking into consideration the advantages and disadvantages of the existing fermentation tanks. In order to maintain the need of mid-temperature fermentation of straw, the thermal equilibrium of fermentation tank is analyzed, and the thermal compensation scheme of fermentation tank is put forward.Finally, the pressure swing adsorption method for biogas separation and purification system is researched to realize the desulphurization and dehydration of biogas, and to convert the harmful H2S into elemental S, thus realizing the separation of biogas from carbon dioxide, which greatly improves the utilization efficiency of methane and expands the application scope of the methane. After the separation, S can be used as chemical raw material, carbon dioxide as food production, and biogas as automobile fuel. A highly efficient utilization of biogas is achieved without any waste or hazardous materials produced in the whole production process.