PDMS复合膜回收酯化反应废水中的异丁醇

乙酸与异丁醇酯化反应生产乙酸异丁酯，产生大量含异丁醇的废水，常规生化处理负荷重，浪费资源。采用PDMS复合膜分离回收酯化废水中的异丁醇，考察了异丁醇浓度对PDMS复合膜溶胀度及分离性能的影响，优化渗透汽化过程操作参数，研究了乙酸异丁酯对PDMS复合膜回收异丁醇效果的影响。结果表明，随着异丁醇浓度从1%增大到3%(质量)，PDMS复合膜溶胀度先增大后趋于平稳，异丁醇的渗透通量呈增大趋势，分离因子保持在15左右；操作温度从30℃升至60℃时，渗透通量增大，异丁醇的分离因子下降，总表观活化能为33.87 kJ/mol；流速增加，Reynolds数增大，异丁醇渗透通量变化不大，但分离因子略有增大；微量乙酸异丁酯的存在可促进渗透汽化膜回收异丁醇。采用PDMS复合膜分离酯化废水中的异丁醇，回收率大于94.0%，渗余液中异丁醇浓度可降至0.1%(质量)左右。研究结果可为PDMS复合膜处理低浓度有机溶剂废水提供依据。

Recovery of isobutanol from esterified wastewater by PDMS composite membrane

The esterification reaction of acetic acid and isobutanol produces isobutyl acetate, which generates a large amount of wastewater containing isobutanol. The conventional biochemical treatment is heavy and wastes resources. The effects of isobutanol concentration on the swelling degree and separation performance of polydimethylsiloxane (PDMS) membrane, the operating parameters of the pervaporation process and the effect of isobutyl acetate on the recovery of isobutanol by PDMS membrane were studied. The results show that with the isobutanol concentration increases from 1%(mass) to 3%(mass), the swelling degree of the PDMS membrane increases first and then stabilizes, the flux of isobutanol increases, and the separation factor is about 15. When the operating temperature increases from 30℃ to 60℃, the flux increases, the separation factor of isobutanol decreases, and the total apparent activation energy is 33.87 kJ/mol. With increase of the flow rate, the isobutanol flux is stability while the separation factor increases slightly. The trace amounts of isobutyl acetate can promote the recovery of isobutanol by the membrane. The recovery rate of isobutanol by PDMS membrane is greater than 94.0%, and the concentration of isobutanol in the retentate can be reduced to 0.1%(mass). The research results can provide a basis for PDMS composite membrane to treat low-concentration organic solvent wastewater.