A SIMPLIFIED METHOD FOR THE SYNTHESIS OF GAS SEPARATION MEMBRANE CASCADES WITH LIMITED NUMBERS OF COMPRESSORS

An alternate easy-to-use procedure is presented to draw n-compressor m embrane cascades for gas separation applications with n greater than o r equal to 1. First, a master cascade is created by inserting 'introdu ced' membrane stages in a known membrane cascade containing a large nu mber of compressors. Then an n-compressor cascade containing the maxim um number of membrane stages is generated from the master cascade by e liminating the unwanted recycle-compressors and the membrane stages as sociated with these eliminated recycle-compressors. From the resulting n-compressor cascade, only the introduced membrane stages are then re moved to yield an n-compressor cascade with the desired lower number o f membrane stages. When substructures containing n-compressors are gen erated from a master cascade, equations are derived to provide informa tion such as the maximum and the minimum number of membrane stages whi ch can be present in these substructures, the number of substructure c ascade schemes with a given number of membrane stages and the total nu mber of feasible substructure cascade schemes. (C) 1997 Elsevier Scien ce Ltd.