Theoretical modeling of the hybrid membrane-gas hydrate crystallisation process for xenon recovery

Abstract

A mathematical model of the hybrid membrane-gas hydrate crystallisation for xenon (Xe) recovery from binary gas mixtures approximated to natural gas composition and normalised by 100% is considered. The first gas mixture is CO2 (97.09 vol.%) and Xe (2.91 vol.%). The second gas mixture is H2S (97.09 vol.%) and Xe (2.91 vol.%). The third gas mixture is CH4 (99.84 vol.%) and Xe (0.16 vol.%). Poly(dimethylsiloxane) and Cellulose triacetate membranes are used. The process at the gas hydrate mixture dissociation pressures and the gas hydrate formation temperature is 275.15 K. The dependences of the gas hydrate, the membrane, the hybrid membrane-gas hydrate Xe recoveries through the membranes versus gas mixture withdrawn are obtained. Xe has the good gas hydrate-forming properties and will the most effective concentration in the gas hydrate phase. For the most efficient Xe recovery in the membrane-gas hydrate module must not be impurities with the gas hydrate dissociation pressure and permeability through the membrane close to Xe. It is shown that the largest Xe recovery is 20.08 in CH4 (99.84 vol.%) and Xe (0.16 vol.%) gas mixture. Thus, the efficiently Xe recovery from the main natural gas component – CH4 by the hybrid membrane-gas hydrate crystallisation is possible.