Separation of the propane propylene mixture with high recovery by a dual PSA process

Abstract

Propylene is a very important raw material in the petrochemical industry. A key step in its production is propane/propylene separation, where energy consumption and the degree of propylene recovery achieved have a strong impact on the economy of the process. A Dual PSA process has been designed for the separation of a 50:50 molar propane/propylene mixture using zeolite 13X as adsorbent. Kinetic and equilibrium adsorption parameters reported in the literature (Da Silva, F.A., Rodrigues A.E., 2001. AIChE J. 47, 341–57) have been used. The process can produce polymer-grade propylene (purity > 99.5%) with recovery higher than 99.5%, which is above the recovery achieved in other PSA processes studied in the literature for an equimolar propane/propylene mixture. Energy consumption is 38% lower than required by conventional distillation.