Experimental Researches On Supercritical Hydrated Extraction

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.