Patent ID: 7578871
Filing Date: 2009-08-25
Classification: B01D

Abstract:
1. A gas separation membrane module, comprising: a) a plurality of hollow fibers formed of a membrane which exhibits selectivity between gaseous components of a feed stream, the module having a feed end and a product end, the fibers extending from the feed end to the product end, b) the fibers define bores comprising generally straight paths for a feed gas from the feed end to the product end, wherein gas which does not permeate through the fibers and remains within the bores is called a non-permeate gas, c) the module includes first and second regions, the first region being located in a vicinity of the feed end, the second region comprising a remainder of the module excluding the first region and including a vicinity of the product end, d) wherein the fibers are coated, in the second region only, with a material which improves selectivity of the membrane, and wherein the fibers in the first region are uncoated, e) wherein feed gas entering the module first passes through the uncoated fibers and then passes through only the coated fibers for a remainder of its passage through the module, and wherein the non-permeate gas flows only from the feed end to the product end.