The Study Of Methyl Acetate Synthesis By Reactive Distillation

It is a classical chemical process for production of methyl acetate. But by the limits of. the formation of azeotropes in the process, we can't obtain hign purity methyl acetate by normal unit operation. In this paper, we done proof-tests based on simulation calculation. Then, we designed a reactive distillation equipment, that it produces methyl acetate which can be used for carbonylation synthesizing acetic anhydride. After the commercial unit being built up, it will upgrade the makeup of industry of Shanghai Coking & Chemical Plants.Relied on the results of the modeling and simulation for process, we produce methyl acetate by reactive distillation on a pilot plant. The process has been simulated and optimized, and 99.5 wt% methyl acetate has been obtained in one column with 98% 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 indiameter has been designed in this paper and experiment has been done in Shanghai Coking & Chemical Plants 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.Based on the above jobs, a reactive/distillation column which is 20000t/year in production also has been designed and the column is 42.7 meters high with 78 CTST trays, φ 1200/ φ 1600 in diameter. The study is a successful case of the combination of computer simulation and experimentation. It means that it's a new developmental way for the exploitation of the projects of corporation.