Patent ID: 6830691
Filing Date: 2004-12-14
Classification: B01D,C01B,Y02P

Abstract:
A process using perm-selective membranes in multiple groups for simultaneous recovery of a permeate product and a desired non-permeate product from a fluid mixture of compounds, which process comprises:(1-a) providing a feedstream comprising a mixture of an alkane compound having from 2 to about 4 carbon atoms and an alkene compound having the same number of carbon atom as the predominate component of the feedstream, (1-b) providing apparatus comprising a plurality of membrane modules each including first and second zones separated by a solid perm-selective membrane which under a suitable differential of a driving force exhibits a permeability of at least 0.1 Barrer for one of the compounds of the feedstock, each first zone having at least one inlet and outlet for flow of fluid in contact with the membrane, and contiguous with the opposite side thereof a second zone having at least one outlet for flow of permeate, and the membrane modules of the apparatus are disposed in a first product group, a second product group, and at least one intermediate group, which intermediate group has membranes of higher selectivity than the membranes in at least one of the other groups, (1-c) introducing the feedstream into the first zone of one or more of the intermediate modules under conditions suitable for permeation, and thereby obtaining permeate effluents and non-permeate streams from the intermediate modules, (1-d) distributing the non-permeate streams from the intermediate modules into the first zone of one or more of the second product modules under conditions suitable for permeation, (1-e) collecting the permeate effluents from the second zones of the intermediate group of modules and distributing the permeates into the first zones of the first product group modules under conditions suitable for permeation, thereby obtaining non-permeate streams and final permeate product streams from the first product modules, and (1-f) distributing the non-permeate streams from the first product modules into the first zone of one or more of the intermediate modules under conditions suitable for permeation.