陶瓷超滤膜在乳酸纯化工艺中的应用

The application of ultrafiltration ceramic membrane in the process of lactic acid purification

把陶瓷超滤膜技术应用于乳酸纯化工艺当中，通过实验，确定了影响膜分离性能的关键参数，并对膜的污染机理及清洗方法进行了研究。结果表明：采用孔径为30nm的陶瓷超滤膜，对乳酸钙含量为16％左右，pH为9的乳酸发酵液，采用过膜压差为0．35MPa，膜面流速为5ms^-1，在操作温度为80℃下，控制浓缩倍数为8倍的条件下，陶瓷超滤膜的渗透液品质优良，膜过滤通量维持在80～90L·m^-2·h^-2。从技术的角度，采用陶瓷超滤膜完全能代替原有的板框及沉淀工序。

After experiments by adopting the ultratlhration ceramic membrane technology into the process of lactic acid purification, we identified the key parameters that impact the function of membrane separation and had a study on membrane fouling mechanism and cleaning methods. The result shows that, for lactic acid fermentation solution with a calcium lactate content of around 16% and a pH value of 9, under the following conditions, the quality of filtered solution is excellent, and that the flow volume could be kept at 80-90L· m^-2· h^-1 a） use uhrafiltration ceramic membranes with a channel diameter of 30mm; b） keep a differential pressure of passing membrane at 0. 35Mpa; c） control flowing speed through membrane surface at 5m·s^-1 ; d） make operation temperature at 80℃ ; e） keep a concentration multiplier of 8x. From technical angle, it is completely workable to use ultrafihration ceramic membrane instead of the previous filter plate and precipitation process.