膜分離技術,被認為是21世紀工業(yè)技術改造中的一項極為重要的技術。隨著性能優(yōu)異的新型膜材料不斷涌現(xiàn),進一步開發(fā)出用于沼氣脫碳的低成本膜分離技術,將有助于生物燃氣產業(yè)的發(fā)展。
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.
沼氣膜分離是指在壓力差為推動力的作用下,利用沼氣中各組分在氣體分離膜中滲透速率的不同而達到分離純化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.
當無液態(tài)水、無油的壓縮沼氣沿中空纖維管內腔流動時,各種氣體的分壓在中空纖維絲管的高壓側(原料側)與低壓側(滲透側)所形成的驅動力——分壓差作用下,溶解系數(shù)和擴散系數(shù)大的氣體(如CO2)優(yōu)先通過管壁,其余氣體(CH4)相對受到阻隔,從而達到分離的目的。
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.
目前適用于沼氣提純的膜是聚酰胺膜和EC膜,國內外已有大量沼氣工程使用膜法提出技術,推廣及應用較為廣泛的有美國麥道(Medal)、荷蘭DMT公司、德國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.
膜法分離的特點:
Characteristics of membrane separation:
除電耗外,無額外輔助材料,沒有二次污染;
Except for power consumption, there is no additional auxiliary material and no secondary pollution;
工藝流程簡單、可靠性高;
The process is simple and reliable;
投資及運行費用低;
Low investment and operation cost;
占地面積小、開停車簡單、使用壽命長;
The utility model has the advantages of small floor area, simple start and stop, and long service life;
產品CH4純度可達≥95%;
The CH4 purity of the product can be more than 95%;
安裝快速簡單。
Quick and easy installation.