膜吸收法净化低浓度甲醛和氨气

Purification of simulated low-concentration formaldehyde and ammonia by membrane absorption method

基于膜吸收技术自制双层平板式膜吸收器,搭建净化低浓度甲醛和氨气污染模拟系统,考察不同膜结构参数、进气流量、吸收剂流量等因素对其净化效果的影响。结果表明,聚偏氟乙烯PVDF对低浓度甲醛和氨气的净化效率高于聚四氟乙烯PTFE。对同一材质膜,随着膜孔隙率的增大,甲醛和氨气的净化率呈上升趋势。随着进气流量的增加,甲醛和氨气的净化效率降低;而吸收剂流量对其净化效率影响不大。对于所有实验条件,平均膜孔径为0.22μm的PVDF 4#在进气流量u g=120 L/h时,甲醛和氨气的净化效率最高,分别达94.7%和96.3%。

Based on membrane absorption method, a double plate type membrane absorber was developed, then a simulation test system of purification for low-concentration formaldehyde and ammonia was set up. Using the test system, the influences of parameters of membrane, gases flow and absorbent flow on the removal efficien- cy of formaldehyde and ammonia were studied. The results show that the removal efficiency of PVDF membranes on HCHO and NH3 is higher than that of PTFE membranes. As for the same type of membrane, the purification efficiency for HCHO and NH3 increases with the increase of size of the hole of the membrane. The purification ef- ficiency for HCHO and NH3 decreases with the increase of gases flow of inlet. The flow of absorbent has no im- portant impacts on the removal effects. As for all tested conditions, the removal efficiencies of HCHO and NH3 for PVDF 4#（hole size of 0.22μm） are the highest when the gases flow of inlet is 120 L/H, and reach 94.7% and 96.3% , respectively.