Harasimowicz M, Orluk P, Zakrzewska-Trznadel G, Chmielewski A G
Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland.
J Hazard Mater. 2007 Jun 18;144(3):698-702. doi: 10.1016/j.jhazmat.2007.01.098. Epub 2007 Jan 30.
Biogas is a clean environment friendly fuel that is produced by bacterial conversion of organic matter under anaerobic (oxygen-free) conditions. Raw biogas contains about 55-65% methane (CH(4)), 30-45% carbon dioxide (CO(2)), traces of hydrogen sulphide (H(2)S) and fractions of water vapour. Pure methane has a calorific value of 9100 kcal/m(3) at 15.5 degrees C and 1 atm; the calorific value of biogas varies from 4800 to 6900 kcal/m(3). To achieve the standard composition of the biogas and calorific value of 5500 kcal/m(3) the treatment techniques like absorption or membrane separation should be applied. In the paper the results of the tests of the CH(4) enrichment in simulated biogas mixture consisted of methane, carbon dioxide and hydrogen sulphide were presented. It was showed that using the capillary module with polyimide membranes it was possible to achieve the enrichment of CH(4) from the concentrations of 55-85% up to 91-94.4%. The membrane material was resistant to the small concentrations of sour gases and assured the reduction of H(2)S and water vapour concentrations, as well. The required enrichment was achieved in the single module, however to prevent CH(4) losses the multistage or hybrid systems should be used to improve process efficiency.
沼气是一种清洁环保的燃料，它是通过在厌氧（无氧）条件下细菌对有机物质的转化而产生的。原始沼气含有约55 - 65%的甲烷（CH₄）、30 - 45%的二氧化碳（CO₂）、微量的硫化氢（H₂S）以及少量的水蒸气。纯甲烷在15.5℃和1个大气压下的热值为9100千卡/立方米；沼气的热值在4800至6900千卡/立方米之间变化。为了达到沼气的标准组成和5500千卡/立方米的热值，应采用吸收或膜分离等处理技术。本文介绍了在由甲烷、二氧化碳和硫化氢组成的模拟沼气混合物中进行甲烷富集测试的结果。结果表明，使用带有聚酰亚胺膜的毛细管模块，可以将甲烷浓度从55 - 85%提高到91 - 94.4%。该膜材料对低浓度酸性气体具有抗性，并且还能确保降低硫化氢和水蒸气的浓度。在单个模块中实现了所需的富集，然而，为防止甲烷损失，应使用多级或混合系统来提高工艺效率。
