Patent Number: 6,252,038

Title: Method for selectively separating hydrocarbons

Abstract: A method for separating specific hydrocarbons from a hydrocarbon mixture of hydrocarbons using a membrane made of a fluorine-containing polyimide resin having high separation ability with regard to certain hydrocarbons, and a high resistance to hydrocarbon is disclosed. The method is of high practicability with regard to performance and cost. Certain hydrocarbons permeate selectively and are separated by bringing a hydrocarbon mixture into contact with a membrane having a fluorine-containing polyimide resin as its main component, whose main component is the minimum repeating unit expressed by ##STR1## The mixture is passed through the membrane, thereby selectively permeating, for example, unsaturated hydrocarbons. The main component of the membrane is a fluorine-containing polyimide resin with a fractional free volume in the range of 0.130-0.175.

Inventors: Shimazu; Akira (Ibaraki, JP), Matsushita; Tomoko (Ibaraki, JP), Miyazaki; Tsukasa (Ibaraki, JP), Ikeda; Kenichi (Ibaraki, JP)

Assignee: Petroleum Energy Center

International Classification: B01D 53/22 (20060101); B01D 71/00 (20060101); B01D 71/64 (20060101); C08F 006/12 ()

Expiration Date: 06/26/2018