Study on the effect of process parameters on CO_2/CH_4 binary gas separation performance over NH_2-MIL-53(Al)/cellulose acetate hollow fiber mixed matrix membrane

摘要

The aim of current work is to study the interaction of process parameters including, temperature, CO_2 feed composition and feed pressure were towards CO_2 separation from CO_2/CH_4 binary gas mixture over hollow fiber mixed matrix membrane using design of experiment (DoE) approach. The hollow fiber mixed matrix membrane (HFMMM) containing NH_2-MIL-53(Al) filler and cellulose acetate polymer was successfully spun and fibers with outer diameter of approximately 250-290 nm were obtained. The separation results revealed that the increment of temperature from 30 °C to 50 °C reduced the CO_2/CH4 separation factor while, increasing feed pressure from 3 bar to 15 and increment of CO_2 feed composition from 15 to 42.5 vol% increased the separation factor of HFMMM. The DoE results showed that the feed pressure was the most significant process parameter that intensely affected the CH4 permeance, CO_2 permeance and CO_2/CH4 separation factor. Based on the experimental results obtained, maximum CO_2 permeance of 3.82 GPU was achieved at feed pressure of 3 bar, temperature of 50 °C and CO_2 feed composition of 70 vol%. Meanwhile, minimum CH4 permeance of 0.01 GPU was obtained at feed pressure of 15 bar and temperature of 30 °C and CO_2 feed composition of 70 vol%. Besides, maximum CO_2/CH4 separation factor of 14.4 was achieved at feed pressure of 15 bar and temperature of 30 °C and CO_2 feed composition of 15 vol%. Overall, the study on the interaction between separation processes parameters using central composite design (CCD) coupled with response surface methodology (RSM) possesses significant importance prior to the application of NH_2-MIL-53(Al)/Cellulose Acetate HFMMM at industrial scale of natural gas purification.