| abstract |
PROBLEM TO BE SOLVED: To provide an unsaturated hydrocarbon from a mixture containing an unsaturated hydrocarbon, which has high separation performance and resistance to unsaturated hydrocarbons and is practically satisfactory in both performance and cost. And a separation membrane used for the method. SOLUTION: A membrane containing cellulose ester and silica as main components, and a membrane for separating unsaturated hydrocarbons having a maximum silica content in an intermediate region in the thickness direction of the membrane, and this separation. One side of the membrane is contacted with a mixture containing unsaturated hydrocarbons and the unsaturated hydrocarbons are selectively permeated and separated through the membrane. The white line at the bottom of the figure shows the content of the Si element, the content of silica is different from the thickness direction of the film, and the silica maintains the concentration gradient in the thickness direction of the film. Existing. |