乙烯气相氧化法制备醋酸乙烯酯清洁生产技术

In order to develop a clean production technology for the preparation of vinyl acetate by gas-phase oxidation of ethylene, a simulation process with an annual output 100 kt/a of vinyl acetate (VAC) and by-product 1.9 kt/a of acetaldehyde was established. Multi-effect vacuum evaporation was adopted to recover acetic acid efficiently. The carbon dioxide could be effectively recovered by temperature swing adsorption to remove both ethylene and water. The energy consumption was effectively decreased by the application of heat pump assisted distillation, pressure swing absorption with low heat source and heat exchange networks. The simulation results showed that the carbon emission was reduced by 46.8% using the purification of CO₂ with the molecular sieve adsorption. The energy consumption of 18.8% was saved by the optimization of heat exchange networks of the system device. At the same time, the energy consumption was also saved by about 57.5% and 54.9%, respectively, by the application of heat pump assisted distillation and pressure swing absorption with low heat source techniques. The comprehensive energy consumption was 0.142 tce/t, which was 40% lower than the advanced value.