Olefin Paraffin separation
Permylene uses membranes made from chitosan for its separation process. Chitosan is a natural source polymer derived from chitin, the major structural constituent of the exoskeleton of crustaceans and insects. The membranes are designed for industrial conditions, and installed in an industry standard spiral wound membrane element format.
In a petrochemical plant, an olefin-paraffin feed mixture is fed into the membrane element which separates the gases. The process is modular and highly scalable, allowing for the installation of any number of membrane elements depending on the plant production capacity.
The robust Permylene membrane technology results in high separation performance that delivers polymer-grade olefins. The composition of the Permylene membrane allows ethylene, propylene and other olefins to chemically interact with it, facilitating olefin transport across it while rejecting paraffins and other constituents.
Steady and stable olefin transport is achieved in continuous, non-stop operation via circulation of an aqueous silver nitrate solution over a spiral wound membrane containing a hydrogel coating.
- The silver ions in the silver nitrate solution within the hydrogel structure form a reversible complex with the double bonds of the olefin molecules
- Any molecules not possessing a double bond are rejected, resulting in excellent selectivity
- The process is primarily driven by the olefin partial pressure differential across the Permylene membrane resulting in commercially attractive permeation rates