염화탄화수소를 포함하는 혼합가스 하이드레이트의 상평형 및 분광학적인 해석

Abstract

In this study, The formation of solid hydrates by certain chlorinated hydrocarbons methylene chloride(CH_2Cl_2), carbon tetrachloride(CCl_4), 1,2-dichloroethane(CH_2ClCH_2Cl) and 1,1,1-trichloroethane(CH_3CCl_3) and water were attempted experimentally with nontoxic and common help gases such as CO_2, CH_4 and N_2 for recovering chlorinated hydrocarbons from the aqueous solutions. To check the themodynamic feasibility of this process the pressure and temperature ranges of hydrate stability region were carefully determined through measurement of four-phase equilibria(H-I_W-L_CHC-V) for help gas+water+chlorinated hydrocarbon systems. The help gas+water+chlorinated hydrocarbon systems greatly reduced the hydrate-forming pressure, which confirmed the mixed gas hydrates with chlorinated hydrocarbons more stabilized than the simple hydrates consisting of help gas and water. The degree of stabilization was found to follow the order of CH_2ClCH_2Cl<CH_2Cl_2<CH_3CCl_3<CCl_4. The structure of the mixed gas hydrates was identified as sII and cage occupancies of each cage were obtained through NMR spectroscopy. From close examination of phase equilibrium measurements, a thermodynamic feasibility of this process was confimed. In particular, from the spectroscopic results, both the structure and cage occupancies were determined to estimate the amount of the enclathrated help gas and chlorinated hydrocarbon molecules. From the above results we can suggest a proof-of-concept for recovering chlorinated hydrocarbons from the aqueous solution using hydrate formation in the presence of help gases.