Membrane separation technology is considered to be an extremely important technology in the industrial technological transformation in the 21st century. With the emergence of new membrane materials with excellent performance, further development of high-efficiency and low-cost membrane separation technology for biogas decarbonization will be helpful to recommend the development of biogas industry.

　　沼气膜分离是指在压力差为推动力的作用下，利用沼气中各组分在气体分离膜中渗透速率的不同而达到分离纯化CH4的目的。

　　Biogas membrane separation refers to the separation and purification of CH4 by using the different permeation rates of components in biogas in the gas separation membrane under the driving force of pressure difference.

　　当无液态水、无油的压缩沼气沿中空纤维管内腔流动时，各种气体的分压在中空纤维丝管的高压侧（原料侧）与低压侧（渗透侧）所形成的驱动力——分压差作用下，溶解系数和扩散系数大的气体（如CO2）优先通过管壁，其余气体（CH4）相对受到阻隔，从而达到分离的目的。

　　When the compressed biogas without liquid water and oil flows along the inner cavity of the hollow fiber tube, the partial pressure of various gases is formed by the driving force differential pressure between the high-pressure side (raw material side) and the low-pressure side (permeation side) of the hollow fiber tube, and the gas with large dissolution coefficient and diffusion coefficient (such as CO2) preferentially passes through the tube wall, and the other gases (CH4) are relatively blocked, so as to achieve the partial pressure The purpose of departure.

　　目前最适用于沼气提纯的膜是聚酰胺膜和EC膜，国内外已有大量沼气工程使用膜法提出技术，推广及应用较为广泛的有美国麦道（Medal）、荷兰DMT公司、德国Evonik、挪威Memfoact和日本宇部（UBE）。

　　At present, the most suitable membranes for biogas purification are polyamide membrane and EC membrane. A large number of biogas projects at home and abroad have used membrane methods to propose technologies. The more widely promoted and applied ones are medal in the United States, DMT in the Netherlands, Evonik in Germany, memfoact in Norway and Ube in Japan.

　　膜法分离的特点：

　　Characteristics of membrane separation:

　　除电耗外，无额外辅助材料，没有二次污染；

　　Except for power consumption, there is no additional auxiliary material and no secondary pollution;

　　工艺流程简单、可靠性高；

　　The process is simple and reliable;

　　投资及运行费用低；

　　Low investment and operation cost;

　　占地面积小、开停车简单、使用寿命长；

　　The utility model has the advantages of small floor area, simple start and stop, and long service life;

　　产品CH4纯度可达≥95%；

　　The CH4 purity of the product can be more than 95%;

　　安装快速简单。

　　Quick and easy installation.