Ethane/ethylene and propane/propylene separation in hybrid membrane distillation systems: Optimization and economic analysis

The combination of membrane and distillation processes to form a hybrid separation system is proposed as an alternative design to replace the current distillation technology. The main objective of this work is to scrutinize the feasibility of numerous hybrid membrane distillation (HMD) schemes through simulation. Silver nitrate is used for modeling/simulation as membrane carriers at a concentration of 6 mol L-1. Different configurations are suggested to obtain highest product (ethylene or propylene) purity. These technologies are compared in terms of capital, operating and utility costs with the conventional C2- and C3-splitters. For the ethane/ethylene separation, the membrane cascade system resulted in the highest ethylene purity. However the series configuration is more economical than the membrane cascade system. For propane/propylene separation, the top configuration outperformed the conventional C3-splitter and other HMD configurations in terms of propylene purity. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.