Membrane-based - Solvent Absorption Method To Deal With Benzene

With the better recognition of the harmful effects of waste gas contain benzene on thehuman and environment, concerns over many choiceness characteristics of the remove ofbenzene from waste gas by membrane-based dissolvent absorption have been increasedinto a hotspot throughout the world.In this paper, membrane contactor made of hollow fiber polypropylene membrane(HFPPM) was used as separator. The absorbent was the aqueous solution ofN-Formylmorpholine (NFM). Mass-transfer performance of separating benzene fromC₆H₆/N₂ was studied in HFPPM contactor. The effects of various factors, includingconcentration of absorbent and feeding gas, temperature of absorbent, flow velocity ofabsorbent and feeding gas, and preliminary discuss the H_ben of benzene in the differentconcentration the aqueous solution of N-Formylmorpholine (NFM), operation stability ofHFPPM contactor was experimented initially. The value of the overall mass transfercoefficient of K_G absorption of benzene was predicted by mathematical model of kineticsof mass transfer. The result shows that under the conditions of 20％of NFMconcentration(volume ratio), the range of 64.2mL/min～243.3mL/min of gas flow-rate, therange of 31mL/min～90mL/min of liquid flow-rate and the rang of 462.3ppmv～980.4ppmv of concentration of gas mixtures, the removal efficiency of C₆H₆ absorption areabout 57％～74％and the overall mass transfer coefficient K_G about 0.0028S^-1～0.0046S^-1, The K_G value of calculation was better accordant with experimental value. Inthe system of NFM-C₆H₆, the response process is mostly controlled by liquid-membrane.Meanwhile, the characteristics of separation of C₆H₆ by membrane contactor are of quickermass transfer velocity and higher efficiency of separation.