Studies On The Mutual Solubilities Of Organics--Water Under High Temperature And High Pressure

Near critical water (NCW) is usually referred to hot compressed water in the range of 250 -350 which has changing properties as temperature goes up. NCW has strong tendency to ionize and can act as an effective acid and base catalysts. In addition, NCW has a dielectric constant which is still high enough for it to dissolve and ionize salts, but low enough for it to dissolve organics. As a result, studies on the organic chemical reactions, separations, resource in the NCW have been one of the hot topics in the recent years. As lack of basic data greatly hinders the development of green chemical processes in NCW, studies on the mutual solubilitues of organics-water at high temperature and high pressure in this become very interesting.An apparatus was constructed for determination of mutual solubilities of water-organics in the near-critical region. It can be used to temperature up to 350 and pressure up to 30MPa. The apparatus features small pressure variation, precise temperature control, on-line sampling and resistance to corrosion. The reliability of the apparatus was proved by comparison of the experimental data with literature ones and reproduciblity of the experimental data. From the experiment results we can see that the system error the apparatus is negligible.The mutual solubilities of water-benzene and water-m-dimethylbenzene were systematically determined in the temperature range 100~300 and pressure up to 30MPa.