Continuous process for olefin separation from olefin/paraffin mixtures.

摘要

A new continuous isothermal separation process was developed for olefin separation olefin/paraffin mixtures. The key feature of this process is the combination of two steps: the absorption of olefin by silver ion in an aqueous solution at high pressure and the isothermal regeneration of the absorbing solution by a membrane. This process takes advantages of (1) The specific and reversible interaction between silver ions and olefin molecules and (2) a gradual pressure drop across the membrane. The membrane acts as a stripper by depressurizing the olefin containing silver nitrate solution and silver ion acts as a carrier for olefin between the absorber and desorber. The process was experimentally tested at bench scale using propylene/propane mixtures. Experimental results indicate that propylene selectivity is as high as 50; propylene production rate at the membrane side is as high as 3.36 cm3 (STP)/cm2/min, and process is stable.;A two-stage absorber process, based on this new technology, is proposed for the manufacture of polymer grade propylene from an equimolar propane-propylene mixture. An absorption-distillation hybrid is also proposed for simultaneous production of polymer grade ethylene and propylene from an equimolar mixture of ethane, ethylene, propylene and propane. By substituting absorbers for distillation columns, process energy requirements are significantly less than for conventional C