(160e) Improved Carbon Molecular Sieve Membranes for Mixed Olefins/Paraffins Separations

Chu, Y. H., Georgia Institute of Technology
Yancey, D. F., The Dow Chemical Company
Koros, W. J., Georgia Institute of Technology
Light olefins, such as ethylene (C2H4) and propylene (C3H6), are among the most important building blocks in the modern petrochemical industry. Olefins are primarily produced by thermal cracking of hydrocarbon feedstocks, and a series of separation processes is required to separate valuable olefins from paraffins. Because of the similar properties of the olefin and paraffin pairs, the separation is difficult and costly. For nearly seven decades, distillation has been commonly performed for recovery of olefins from mixtures with their respective paraffins. The distillation process requires energy-intensive operating conditions, including high pressure and low temperature, to perform the challenging separation. It is, therefore, appealing to develop olefins-selective membranes for use in a hybrid membrane-distillation process to retrofit the current distillation separation processes to lower the overall energy usage.

Carbon molecular sieve (CMS) membranes are able to exceed the limitation of the trade-off between productivity and efficiency of traditional polymeric membranes. In this work, starting materials and processing conditions were investigated in order to explore the impact on CMS membranes separation properties for mixed olefins/paraffins. CMS membranes were made having improved olefins/paraffins separation performance, which will be reported.