The Study On Reactive Distillation Of Methyl Acetate Synthesis

It is difficult to obtain high-purity methyl acetate because of the reverse reaction by methanol and acetic acid and the formation of azeotropes. The process has been simulated and optimized, and 99.5 wt% methyl acetate has been obtained in one column with sulfuric acid as catalyst. The conversion of acetic acid is above 99.9%.The simulation based on equilibrium rate model is applied in the process. The rigorous fractionation RadFrac and NRTL equation are chosen in the simulation. The effects of column stage, reflux ratio, feed location and ratio of methanol to acetic acid in feed have been investigated. A better condition is proposed by analyzing the simulation data: 45 stages in theory, methanol fed from the 40th stage, sulfuric acid 20th and acetic acid 10th (the condenser is the 1st stage and the reboiler 45th), reflux ratio 1.2, ratio of methanol to acetic acid in mole 1.2, and ratio of sulfuric acid to acetic acid in weight 0.01.A reactive distillation column which is 16 meters high, Φ 125/ Φ 140 in diameter has been designed and experiment has been done in shanghai to prove the veracity of simulation. In our experiment, a conversion of acetic acid above 99.9% and production stream containing at least 99.5% methyl acetate are achieved. By contrasting, the experiment data are in good agreement with the calculated results.A reactive/distillation column which is 20000t/year in production has been designed and the column is 42.7 meters high with 78 CTST trays, Φ 1200/ Φ 1600 in diameter.