醋酸甲酯与合成气一步合成醋酸乙烯

One-Step Synthesis of Vinyl Acetate from Methyl Acetate and Syngas

以醋酸甲酯、合成气为原料,碘化铑为主催化剂,碘甲烷为助催化剂,碘化锂、醋酸锂为促进剂,醋酸锌为裂解催化剂,一步合成醋酸乙烯,考察了反应温度、压力和时间对醋酸甲酯转化率和产物选择性的影响。结果表明,随着反应温度的升高、H2分压的增大以及反应时间的延长,醋酸甲酯转化率和醋酸乙烯选择性均先增大后减小;随着CO分压的增大,醋酸甲酯转化率逐步增大,醋酸乙烯选择性先增大后减小。最佳反应条件为:反应温度180℃,CO分压2.0 MPa,H2分压2.5MPa,反应时间6h;在此反应条件下,醋酸甲酯转化率达到87.26%;醋酐、二醋酸亚乙酯和醋酸乙烯的选择性分别为30.14%,26.57%和5.44%。在间歇反应釜中进行了醋酸甲酯与合成气一步合成醋酸乙烯过程的本征动力学研究,建立了幂函数型动力学模型,回归了动力学模型参数,并经检验证明模型是合适的。

Vinyl acetate was synthesized from methyl acetate and syngas in the presence of main catalyst rhodium iodide, co-catalyst methyl iodide, promoter lithium iodide, lithium acetate and cracking catalyst zinc acetate. The effects of reaction temperature, pressure, and reaction time on the conversion of methyl acetate and product selectivity were investigated. Results showed that with the increase of reaction temperature, H2 pressure, and reaction time, the conversion of methyl acetate and selectivity of vinyl acetate reached a maximum value and decreased afterwards. With the increase of CO pressure, the conversion of methyl acetate increased and selectivity of vinyl acetate exhibited a maximum. The best reaction result was obtained under these conditions： reaction temperature of 180℃, CO partial pressure of 2.0 MPa, H2 partial pressure of 2.5 MPa, and reaction time of 6 h. Under this condition, the conversion of methyl acetate reached 87.26% and the selectivity of acetic anhydride, ethylene diacetate and vinyl acetate were 30. 14%, 26. 57%, 5. 44%, respectively. By the study of intrinsic kinetic in the batch autoclave of one-step synthesis of vinyl acetate from methyl acetate and syngas, a kinetic model of power function type was presented, and model parameters were regressed. The model was proved to be suitable.