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

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.