超临界流体与膜过程的耦合技术

Coupling Supercritical Fluid Technology with Membrane Processes

介绍了超临界流体与膜过程的耦合技术的研究进展和最新研究成果。将超临界CO_2萃取与纳滤过程相耦合,可以不经历压力、温度和相变循环而使CO_2循环利用,从而降低过程能耗、减小操作费用。将纳滤过程与超临界CO_2萃取相耦合,可以对萃取收率和选择性独立调控,使它们分别达到最佳值,从而实现对萃取物在高收率条件下达到精细分离的目的。将超临界CO_2引入高粘性液体的超滤过程,会在不提高温度和无需引入化学剂的情况下,大大降低流体粘度、增大透过流率、提高过滤效率、减小过程能耗,同时也有利于环境保护、提高产品质量。

The development of coupling supercritical fluid technology with membrane processes has been presented.Integrating both the supercritical CO2 (SCCO2)and the nanofiltration into a single process will gain great advantage in reducing the energy -consumption and the operating cost.The integration makes it possible that a completely pure SCCO2 could be regenerated and recirculated without undergoing the pressure, temperature and thermodynamic phase changes.Both the maximum extraction of compounds and the optimal selectivity of extracted species could be obtained by coupling the nanofiltration with the SCCO2 extraction process.A good control of the whole extraction/separation process can be easily realized with this new process. Introducing the SCCO2 into the ultrafiltration process of high viscosity liquids can form another advanced new process which is enhanced with SCCO2. Due to its low viscosity, low surface tension, high diffusivity and tunable solvent power, SCCO2 makes the ultrafiltration process of high viscosity liquids be carried out with the high permeate flux,low energy consumption and high filtration efficiency without increasing the process temperature or adding specific chemicals. Moreover, the quality of products could be improved and the pressure on environment could be reduced with the process.