壳聚糖/聚丙烯腈复合膜渗透汽化分离乙醇—水混合物

SEPARATION OF ETHANOL—WATER MIXTURES THROUGH CHITOSAN/POLYACRYLONITRILE COMPOSITE MEMBRANE BY PERVAPORATION

本文用脱乙酰度93％的壳聚糖为活性层膜材,在聚丙烯腈多孔膜上复合研制了渗透汽化膜。乙醇—水混合物的分离结果表明:复合膜具有优异的渗透选择性能。渗透条件对复合膜性能影响显著。料液水含量30—85％时60℃、75℃的渗透通量分别为1000、2200g/(m^2.h);10％水含量60℃、75℃的分离因子为250和1060;水渗透通量与温度间呈Arrhenius关系;二次侧压增大,渗透通量和分离因子减小。

The composite membrane was prepared by pouring chitosan whose deacetylation degree was 93％ onto a porous support of polyarcylonitrile. The result of separating ethanol(2)water(1)mixtures by pervaporation showed that water permeated preferentially through the membrane. At 60℃ and 75℃, the permeation rates ranging 30—85wt％ water content in the feed were 1000 and 2200 g/m^2. h, the separation factors at water content of 10wt％ were 250 and 1060, respectively. The permeation rate of water varies with the temperature in accord ance with an Arrhenius equation. The permeation rate and separation factor decrease while increasing downstream pressure.