Experimental Study for Biogas Upgrading by Water Scrubbing under Low Pressure

Abstract

Biogas fuels is effective to alleviate the problem of energy shortage and ecological environment for sustainable developing in rural China. But CO₂ and other impurity in biogas will impede its use for generating high quality energy. In this paper, water scrubbing technology has been used for biogas upgrading under low scrubbing pressure, and the influence of CO₂ removal rate and CO₂ solubility caused by different experimental parameters including the feed gas flow rate, water flow rate and scrubbing pressure were examined, and the experiments dates were analyzed by SPSS17.0, and then the corresponding mathematical models were established. The result showed that, under the three scrubbing pressure level(with normal pressure, 0. 15 Mpa and 0. 3 Mpa), the improve rate of CH volume fraction increased about 15%, and CO₂ volume fraction declined about 20% when scrubbing pressure raised in each level, and under 0.3 Mpa of pressure, with 0.28 of flow rate ratio of gas and liquid, CO₂ removal rate gotten as high as 73.14%.So the method of water scrubbing under low pressure could be used for biogas preliminary upgrading processing when there is rich of water.