Propane and Propylene Separation with Carbon Dioxide at Mild Temperatures by Gas-Phase Simulated Moving Bed in Binderfree Zeolite 13X

This work studiedthe separation of propane and propylene usingcarbon dioxide as a desorbent and binderfree zeolite 13X as adsorbent.The process occurred at a mild temperature (323 K) using the gas-simulatedmoving bed (SMB) technology. Adsorption equilibrium isotherms of propylene,propane, and carbon dioxide were measured gravimetrically in a temperaturerange from 323 to 423 K and a pressure up to 5 bar. Breakthrough experimentswere performed at 323 K and 3 bar. Binary adsorption equilibrium datawere obtained from the dynamic experiments. Non-ideal adsorption behaviorwas observed for the adsorbate-adsorbent pairs; therefore,the multicomponent adsorption equilibrium was predicted with the RAST-aNRTLmodel. An SMB experiment was performed in the gas-SMB unit. For the0.5/0.5 propane/propylene (molar-based) feed composition, a propylenepurity of 98.8% was obtained, with a recovery above 98% and a productivityof 40.8 kg(C3H6) h(-1) m(ads) (-3). This work experimentally demonstrated that it ispossible to produce high-purity propylene with a high recovery usingbinderfree zeolite 13X as adsorbent and carbon dioxide as a desorbentat mild temperature (323 K).

Automated summary

This study focused on the separation of propane and propylene using carbon dioxide as a desorbent and binder-free zeolite 13X as an adsorbent. The gas-simulated moving bed (SMB) technology was utilized at a mild temperature (323 K). The adsorption equilibrium isotherms were measured, and breakthrough experiments were conducted to obtain binary adsorption equilibrium data. The experiment demonstrated the production of high-purity propylene with a high recovery using binder-free zeolite 13X and carbon dioxide as the desorbent at a mild temperature (323 K).