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.
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.
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.
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.
Characteristics of membrane separation:
Except for power consumption, there is no additional auxiliary material and no secondary pollution;
The process is simple and reliable;
Low investment and operation cost;
The utility model has the advantages of small floor area, simple start and stop, and long service life;
The CH4 purity of the product can be more than 95%;
Quick and easy installation.