Hollow Fiber Membrane Preparation And Separation Of Purified Acetylene Process Research

Separation of acetylene from plasma pyrolysis of coal mixture gas was investigated by membrane absorption method and 1-Methyl-2-Pyrrlione(NMP) as absorbent. The influence factors such as membrane materials and operational conditions on the performance of acetylene mass transfer were researched. A mathematical model was established to study the acetylene mass transfer in the membrane contactor.The CS/PEO hollow fiber membrane was prepared by dry-wet phase inversion. And the effect of amount of PEO was studied. The results showed that when the mass ratio of PEO/CS was 1/10, the membrane showed a excellent performance. The large finger-like macrovoids were seen in the cross-section of the membrane. The tensile strength and tensile’s modulus value of the membranes were 5.55 MPa and 128.45 MPa respectively; The bubble point pressure was tested and the value was 0.098 MPa;The porosity determined of the membrane was 65.34%; and the gas permeation test revealed that the gas permeation flux was 1.97×10-4 mL/(cm2·s·Pa). In order to improve the membrane performance, the flow rate of coagulation bath was investigated. The results revealed that the coagulation bath f low rate was 7.5 mL/min, the bubble point pressure of the membrane was 0.082 MPa and the gas permeation flux was 3.39×10-4 mL/(cm2·s·Pa),. The CS/PEO hollow fiber membrane contactor was used to separate acetylene from the gas mixture and the module length was 20 cm. The results displayed that when the acetylene concentration in the feed gas was 8%, the liquid velocity was 0.0799 m/s and gas velocity was 0.21 m/s, the acetylene mass transfer flux was 1.734 mol·m-2·h-1 and absorption efficiency was 79.6%.A PTFE hollow fiber membrane contactor was used to separate the acetylene from gas mixture using NMP as the absorbent. The effects of operation conditions such as liquid velocity, gas velocity, feed gas concentration and module length on acetylene mass transfer flux and absorbent efficiency were investigated. The results showed that acetylene performed a better mass transfer in the PTFE hollow fiber membrane contactor when the liquid velocity was 0.0167 m/s, gas velocity was 0.4739 m/s, the acetylene concentration in the feed gas was 8% and the module length was 30 cm. The acetylene mass transfer flux was 1.222 mol·m-2·h-1 and absorbent efficiency was 92.79%. During 114 hours of C2H2 membrane absorption-thermal desorption cycle process, the acetylene absorption efficiency maintained at 90%.A mathematical model was established to study the acetylene mass transfer in the membrane contactor. And the fitting error was less than 10%. The simulated results showed that the results revealed that the wetting extent of membrane increased with the increase of liquid velocity and was effectively restrained with the increase of gas velocities. It also displayed that liquid phase resistance and wetted membrane phase resistance controlled the acetylene mass transfer in the acetylene absorption process. Compared with PTFE hollow fiber membrane, the CS/PEO hollow fiber membrane was wetted easier. And the absorption performance of the membrane was easily deterioration. With the increase of module length, the membrane was easier wetted and the absorption performance was declined.