Process for Separating Components of a Multi-Component Feed Stream

Abstract

Provided is a process and apparatus for separating a multi-component feed stream wherein a porous separator is used to effectively create, via permeation and phase change, at least three fractions of differing compositions.

1 . A process for separating a multi-component feed stream into fractions comprising the steps of:
 (a) providing a feed stream having at least two fluid components in the same phase;   (b) providing a porous separator having an inflow side and an outflow side;   (c) maintaining across the porous separator a pressure differential comprising a relatively high pressure on the inflow side of the separator and a relatively low pressure on the outflow side of the separator;   (d) bringing the feed stream at the relatively high pressure into contact with the inflow side of the separator and under conditions which effect separation of the components of the feed stream into a retentate which forms on the inflow side of the separator and a permeant fraction, wherein the permeant fraction (i) includes more than one component of the feed stream in a proportion different from that of the feed stream being treated; and (ii) is the source of a liquid permeate fraction and vapor permeate fraction as the permeant fraction passes through the porous separator; and   (e) recovering each of said retentate, liquid permeate fraction, and vapor permeate fraction.   
     
     
         2 . The process of  claim 1  wherein said two components of said feed stream are liquid. 
     
     
         3 . The process of  claim 1  wherein said two components of said feed stream are vapor. 
     
     
         4 . The process of  claim 1  wherein said feed stream comprises three or more components. 
     
     
         5 . The process of  claim 1  wherein said feed stream is azeotropic and said liquid and vapor permeate fractions are nonazeotropic. 
     
     
         6 . The process of  claim 1  wherein steps (a) through (e) occur in the absence of an input of energy. 
     
     
         7 . The process of  claim 1  wherein steps (a) through (e) occur in the presence of an input of energy. 
     
     
         8 . The process of  claim 1  wherein said steps (a) through (e) are repeated a predefined number of times. 
     
     
         9 . An apparatus which is capable of being used for separating into fractions a multi-component feed which contains at least two fluid components in the same phase and in predetermined amounts and having a module which comprises:
 (a) a first pressure chamber having an inlet for receiving the feed stream and an outlet for emitting a portion of the feed stream;   (b) a second pressure chamber;   (c) a porous separator which: (i) is positioned between the first and second pressure chambers, (ii) has a inflow side for receiving said feed stream and an outflow side in communication with said second pressure chamber; and (iii) is adapted to permit passage from the inflow side to the outflow side of but a portion of the fluid components of the stream and in amounts different from said predetermined amounts;   (d) means for maintaining the pressure in the first pressure chamber at a higher value than the pressure in the second pressure chamber to thereby establish   
       a pressure differential across the porous separator;
 (e) a vapor outlet in the second pressure chamber through which vapor in the chamber can be removed; and 
 (f) a liquid outlet in the second pressure chamber through which liquid in the chamber can be removed. 
 
     
     
         10 . The apparatus of  claim 9  having a plurality of said modules in series, wherein the outlet of the first chamber of a module in said series is fluidly connected to the inlet of the first chamber of the immediately subsequent module in said series. 
     
     
         11 . The apparatus of  claim 9  further comprising at least one heat transfer device selected from the group consisting of reboilers and condensers. 
     
     
         12 . The apparatus of  claim 9  wherein said porous separator comprises at least one porous material selected from the group consisting of porous membranes, molecular sieves, zeolite lattices, packed bed substrates, and nanotubes. 
     
     
         13 . The apparatus of  claim 12 , wherein said porous separator further comprises a permeable, nonporous material.