【作者】 陈治辉；

【导师】 裘俊红；

【作者基本信息】 浙江工业大学 ， 化学工程， 2005， 硕士

【摘要】 超临界水合萃取技术是由水合物分离技术和超临界流体萃取技术藕合而成的一门新型的水溶液分离技术,其理论基础是水合物生成动力学理论和萃取特别是近临界或超临界萃取理论。虽然近几十年来国内外学者在这两方面进行了较多的研究,但成果仍然很不成熟,另外对于和该技术密切相关的其他深层次理论如近临界或超临界条件下水合物生成的特殊动力学行为及其对萃取过程的影响机制等也未见有公开报道。该技术缺乏理论指导,发展相当缓慢。论文在本实验室前期研究工作的基础上,大胆探索,着重对超临界水合萃取的理论基础进行了深入的研究。 本文对水合物生成动力学、水合物分离技术、超临界流体萃取技术的研究现状进行了简要的概括,对几种较具代表性的超临界萃取装置进行了简单的分类讨论;设计了超临界水合萃取的工艺流程并建立了一套小试实验装置,该装置有效体积大、搅拌效率高、密封性好、取样操作方便并且对相平衡的扰动较小;对正丁醇水溶液中乙烯水合物的生成动力学行为进行了大量的实验研究,测定了2wt%和5wt%正丁醇水溶液中的53组乙烯水合物生成动力学数据,着重讨论了压力、过冷度和正丁醇浓度对乙烯水合物生成行为的影响,从实验的宏观现象和微观机理两个层次对影响水合物生成的各因素进行了深入的分析阐释,研究范围包括常规气体条件、近临界条件和超临界条件;在自主设计的超临界水合萃取装置上进行了小试实验,获得了8组实验数据并进行了评价;探讨了水合物生成对萃取过程的影响机制;最后提出了该研究目前存在的不足之处并展望了今后研究和发展的几个重要方向,为今后进一步开展该技术的研究提供了理论和实验依据。更多还原

【Abstract】 Supercritical hydrated extraction that integrated hydrate separation with supercritical fluid extraction is an innovative separation technology for aqueous solution, its theoretical foundation is that the theory of hydrate formation kinetics and that of supercritical fluid extraction. Though the domestic and overseas scholars have carried out many researches in these decades, the achievements on the two aspects are still less for developing this new technology. Furthermore, the mechanism of hydrate formation under the supercritical state and the influence of hydrate formation on supercritical fluid extraction were not investigated as yet. So these theories above for the technology were investigated experimentally in this paper.Firstly, the status of researches on the kinetics of hydrate formation, hydrate separation technology and supercritical fluid extraction technology were briefly reviewed. Several representative apparatuses and flows for supercritical fluid extraction were classified and discussed. Secondly, a setup for supercritical hydrated extraction was designed and built. Which is 2 litres in virtual cubage, well airproof and convenient for sampling with feebly disturb in phase equilibrium. The 53 kinetic data of ethylene hydrate formation in aqueous n-butanol systems were obtained. The n-butanol concentrations, 2wt% and 5wt%, were used in all experiments. And 8 experiments on supercritical hydrated extraction were conducted. Ethylene in our experiments was gaseous, nearcritical and supercritical state. The factors that affected ethylene hydrate formation such as pressure, temperature and n-butanol concentrations were analyzed in macroscopical and microcosmic scopes in detail. The influence of hydrate formation on supercritical fluid extraction was investigated. Finally, several improved projects for the imperfections in our experiments were suggested, and the opinions on future studies were put forward.更多还原