Membrane separation processes and systems for enhanced permeant recovery

Abstract

Membrane separation processes and systems are disclosed that pass a portion of the feed ( 102 ) to the permeate side of the membrane ( 104 ) to reduce membrane surface area and thus provide economically attractive processes and systems for treating large volume refinery and chemical process streams.

1 . A membrane separation system comprising:
 a. a membrane separator ( 104 ) having selective permeation membrane therein adapted to define a retentate side and a permeate side,   b. at least one feed conduit ( 102 ) adapted to provide a fluid feed containing at least two components to be separated to the retentate side,   c. at least one by-pass conduit ( 110 ) adapted remove a portion of the fluid feed such that it does not pass through said membrane,   d. at least one conduit ( 108 ) adapted to withdraw from the retentate side a retentate fraction, and   e. at least one conduit ( 106 ) adapted to withdraw from the permeate side a permeate fraction,   
       in which conduit ( 110 ) is in fluid communication with at least a portion of the permeate fraction. 
     
     
         2 . The system of  claim 1  in which conduit (e) is in fluid communication with a reactor ( 112 ). 
     
     
         3 . The system of  claim 1  in which conduit ( 110 ) is within the membrane separator. 
     
     
         4 . A membrane separation system comprising:
 a. a membrane separator ( 206 ) having selective permeation membrane therein adapted to define a retentate side and a permeate side,   b. at least one feed conduit ( 202 ) adapted to provide a fluid feed containing at least two components to be separated to the retentate side,   c. at least one by-pass conduit ( 212 ) adapted remove a portion of the fluid feed such that it does not pass through said membrane,   d. at least one conduit ( 206 ) adapted to withdraw from the retentate side a retentate fraction,   e. at least one conduit ( 210 ) adapted to withdraw from the permeate side a permeate fraction, in which conduit ( 212 ) is in fluid communication with at least a portion of the permeate fraction,   f. at least one sensor on conduit ( 202 ) adapted to determine at least one of feed flow rate and composition and adapted to provide a signal corresponding to such determination, and   g. a valve ( 214 ) positioned to control the rate of flow through conduit ( 212 ) responsive to the signal from the sensor.   
     
     
         5 . The system of  claim 4  having a central processing unit adapted to receive the signal from the sensor and to instruct the valve (g) to control the rate of flow through conduit (c).