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

摘要

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. AlChE 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.