Biogas is a gaseous mixture produced from microbial digestion of organic materials in the absence of oxygen. Raw biogas, depending upon organic materials, digestion time and process conditions, contains about 45-75% methane, 30-50% carbon dioxide, 0.3% of hydrogen sulfide gas and fraction of water vapor. Pure methane has a caloric value of 34,400 kJ/m³, but the lower heating value of raw biogas changes between 13,720 and 27,440 kJ/m³. To achieve the standard composition of the biogas the treatment techniques like absorption must be applied. In this paper the experimental results of the methane purification in simulated biogas mixture consisted of methane, carbon dioxide and hydrogen sulfide were presented. The air-lift reactor is performed with MEA in order to increase the simultaneous purification for the gaseous mixtures of CO2 and H2S which are main components of the biogas. The effects of feed pressures and mixed gas on the separation of CO2-CH4 by membrane are investigated. It was shown that it was possible to achieve the purification of methane from the concentration of 55% up to 99%. The flow cell reactor was used to measure the reaction rate constant and to determine the optimal conditions of process for improving process efficiency.

• Young G. Park(Daejin University)