The Study On Gas Separation Using PDMS/PPESK Compound Membrane And Its Pilot Scale Module

Using Poly(phthalazinone ether sulfone ketone)(PPESK) as the membrane material, N-methyl-2-pyrrolidinone(NMP) as solvent,1-propanol(PrOH) and LiCl as nonsolvent, Polydimethylsiloxane(PDMS) as coating material, the PDMS/PPESK compound membrane for gas peparation was prepared and the performance of the membrane was studied.The structure and performance of the PMDS/PPESK compound membranes prepared had been researched. The effect of PPESK contain, nonsolvent contain, evaporation time, temperature of coagulant media, PDMS contain, curing temperature and curing time had been systemically researched. The structure research and character analysis were made with SEM, gas permeability and separation coefficient were also researched. It was found that an increase in nonsolvent contain could raise membrane permeation rate but decrease the membrane separation performance, the high temperature coagulant media could improve the membrane permeation rate and decrease separation performance, the high PDMS contain could improve the membrane separation performance and decrease the permeation rate rapidly.The effect of evaporation time on membrane performance was not very obvious. An appropriate curing temperature and enough curing time were needed in the coating quality. Summary from research, the preparation technology of membranes for gas separation were got.The membrane modules for pilot scale experiment are made and the effect of feed flow temperature, VOCs concentration, feed flow pressure and exhaust pressure on membrane module performance.It was found that an increase in feed flow temperature can raise the permeability and decrease the selectivity, both feed flow pressure and exhaoust pressure could increase the VOCs removal rate. The removal rate increased while VOCs concentration increase when the VOCs concentration was low and decreased while VOCs concentration increased when it was high. In the experiment, the membrane module showed the VOCs removal rate reach 70% at the feed flow pressure 0.5MPa, exhaoust pressure 0.02MPa.The effect of temperature, concentration and flow rate of feed solution on the performance of pervaporation composite was studied. The results showed that permeation flux increased and separation factor decreased when temperature of feed solution increased; permeation flux increased and separation factor decreased when the concentration of feed solution increased, permeation flux and separation factor increased when the flow rate of feed solution increased.