A MODIFIED HOLLOW-FIBER CONTAINED LIQUID MEMBRANE TECHNIQUE FOR GAS SEPARATION AT HIGH-PRESSURES

The hollow fiber contained liquid membrane (HFCLM) permeation techniqu e has been modified by using microporous fibers having a thin nonporou s silicone coating to handle higher gas pressures. Separation of vario us CO2-N2 mixtures have been studied over a feed pressure range of 50- 200 psig. Pure water and aqueous 20% diethanolamine (DEA) were used as liquid membranes. Two modes of operation, conventional polymeric memb rane and sweep gas mode, were investigated. Permeator conditions studi ed include liquid membrane pressure higher and lower than the feed pre ssure. The aqueous 20% DEA resulted in significantly higher overall CO 2 permeabilities and selectivity. A mathematical model was developed w hich included the pressure drop inside the fiber bores. Numerical simu lations of the model describe the experimental results well.