Production of mixed-matrix membrane (psf/zeolite) for co2 / n2 separation: screening study of polymer concentration

• Main Author: Chen, Chee Lek
• Format: Undergraduates Project Papers
• Language: English
• Published: 2014
• Subjects: TP Chemical technology
• Online Access: http://umpir.ump.edu.my/id/eprint/9246/1/cd8526.pdf; http://umpir.ump.edu.my/id/eprint/9246/

This research investigated the permeability of CO2 and N2 as well as selectivity of CO2 over N2 of polysulfone (PSF) mixed matrix membranes filled with zeolite 4Å particles. The mixed matrix membrane was prepared by immersion precipitation method with zeolite and PSf were ranged from 10 to 30 W/V% dissolved in the NMP varied from 75 to 100 cm3. The mixture was then mixed homogenously and utilized to determine the permeation rates of N2 and CO2. It is characterized by FTIR and the gas separation performance is analysed by Design of Expert (DOE) method. In accordance to our expectation, FTIR results revealed that the intensity at 3596.17 cm−1 described the existence of an interaction between polymer and zeolite. The permeability of CO2 through the membrane was in higher range from 9.873 to 11.641 GPU. At lower operating pressure, the greater solubility of gas encourages a higher permeation rate. The single concentration variable has low effect, however the interaction between PSf and NMP (BC) has considerable effect on the permeability of CO2 with the highest F value of 0.46. NMP exhibited a high degree of polarity and hydrogen bonding which led to effect of selective skin and permeation rate. The more solvent evaporated, the thicker the concentrated polymer region which then leads to a thicker selective skin and a reduction in permeation rate. The interaction of zeolite and PSf had the least significant effect on the selectivity of CO2 over N2 due to the lower F value with 0.023, however the interaction had higher permeability of CO2 with the F value of 0.45. The cause of low permeability of CO2 was poor association between the zeolite and the polymer leading to an increased in free volume within the membrane. Although it enhanced the permeability of CO2, but it limited the sieving mechanism which resulted low selectivity of CO2 over N2. The model regression equations were evaluated by F-test ANOVA which revealed that these regressions are statistically significant at 95% confidence level to screening the permeability of CO2 and N2 as well as selectivity of CO2/N2. In future research, optimisation is proposed based on the screening study of PSf and zeolite concentration ranged from 22.30 to 27.45 W/V% to stress on the high permeability and selectivity CO2/N2 separation membranes