关键词: 醋酸甲酯, 超临界, 近临界, 水解

Abstract: Near-and supercritical water is an excellent medium for conducting chemical reactions, and is especially propitious to the development of environmentally benign techniques for acid/base catalyzed organic reactions. The work presented in this paper focuses on experimental investigation on noncatalytic hydrolysis for methyl acetate, trying to overcome high energy consumption and other defects of conventional ones. Hydrolysis of methyl acetate(5%) in this work was carried out in a tubular reactor under near-or supercritical conditions(523-673 K, 23-32 MPa), and characteristic of hydrolysis was investigated via combining various reaction conditions. The experimental results show that under the optimized operating condition conversion of methyl acetate achieves thermodynamic equilibrium within 150 to 300 s, the selectivity of which process closes to 1, with no acid catalyst added. Due to phase transition resulted from broad experimental range and singularity of supercritical zone, the influence of temperature and pressure on the reactivity takes on a complicated trend, transition-state theory and cluster theory were adopted to interpret experimental phenomena, also reaction kinetics was established based on S_N2 mechanism. Conclusion drawn from this work indicates the promising prospect of applying near-and supercritical reaction technology to the industrial practice of hydrolysis of methyl acetate.

Key words: Methyl acetate, Supercritical, Near-critical, Hydrolysis