High selectivity polyimide membrane for natural gas upgrading and hydrogen purification

摘要

A polyimide polymer having hydroxyl and acetoxy function groups is provided together with a membrane made from the polymer. Also provided is a process for separating at least one gas from a mixture of gases using a polyimide membrane comprising a polyimide polymer with hydroxyl and acetoxy functional the process comprising: (a) providing the polyimide membrane comprising the polyimide polymer with hydroxyl and acetoxy functional groups which is permeable to the at least one gas; (b) contacting the mixture on one side of the polyimide membrane to cause said at least one gas to permeate the membrane; and (c) removing from the opposite side of the membrane a permeate gas composition comprising a portion of said at least one gas which permeated the polyimide membrane.

主权项

1. A polyimide membrane comprising a polyimide polymer with hydroxyl and acetoxy functional groups wherein the molar ratio of said hydroxyl functional groups to said acetoxy functional groups is in a range of 1:1 to 8:1 wherein said polyimide polymer comprises a plurality of repeating units of formula (I), wherein formula (I) is wherein n and m are independent integers from 20 to 500; wherein n:m is in a range of 1:1 to 8:1.