Abstract: The microfiltration process of solvent naphtha containing impurities was studied with a ceramic membrane of average pore diameter 0.2 mm. Both feeds of solvent naphtha without water and solvent naphtha containing 0.5%(w) water were selected. The effects of operating time, trans-membrane pressure, cross-flow velocity, temperature and aluminum powder content on permeate flux and aluminum powder rejection were investigated, respectively. Furthermore, backflushing experiment, concentration experiment and cleaning of fouled membrane were also studied. The results show that permeate flux of solvent naphtha without water is much higher than that of the solvent naphtha containing 0.5%(w) water. With increasing operating time, permeate flux decreases gradually to a steady value, and the rejection of aluminum powder increases rapidly to 100%. Steady-state flux is enhanced with increasing trans-membrane pressure or temperature, and increased to a maximum value with the increase of cross-flow velocity. The higher the content of aluminum powder, the higher the permeate flux. Optimum operating parameters are trans-membrane pressure 0.16 MPa, cross-flow velocity 3.9 m/s and temperature 40℃. The backflushing can increase efficiently permeate flux. In the process of concentration, permeate flux decreases to a steady value, and then decreases rapidly. Purified solvent naphtha is transparent. In addition, permeate flux could be recovered effectively to 94.9% of new membrane flux by using 0.15%(w) commercial detergent and 0.25%(w) nitric acid, respectively.

Key words: solvent naphtha, ceramic membrane, microfiltration, membrane cleaning

摘要： 研究了平均孔径0.2 mm的陶瓷膜对含杂质溶剂油的微滤过程，选用不加水和加0.5%(w)水2种料液，考察了操作时间、跨膜压差、错流速度、温度和铝粉含量对膜通量及铝粉截留率的影响，研究了反冲操作、浓缩和污染膜清洗过程. 结果表明，不加水较加水料液的膜通量明显增大；随操作时间延长，膜通量下降至稳定，铝粉截留率迅速增大至100%；跨膜压差增大或温度升高使稳定通量增大；错流速度增大，稳定通量先升高之后不变；铝粉含量越高，膜通量越低. 适宜的操作参数为跨膜压差0.16 MPa、错流流速3.9 m/s和温度40℃. 反冲操作能有效提高膜通量；浓缩过程中膜通量快速下降至平缓阶段再较快降低，净化溶剂油澄清透明；采用0.15%(w)洗洁精和0.25%(w)硝酸清洗可使通量恢复到新膜通量的94.9%.

关键词: 溶剂油, 陶瓷膜, 微滤, 膜清洗