SIMULATION OF BATCH REACTIVE DISTILLATION FOR PRODUCING OF METHYL ACETATE

Batch distillation process is one of the major operations in the chemical, petroleum and pharmaceutical industries for the separation of liquid mixtures into their pure components The present work is concerned with constructing a simulation computer programs to analyze multi-components,multistage batch distillation without and with chemical reaction.The rigorous method was used to build the simulation computer programs for non ideal mixtures, by using MATLAB package to solve MESH and MESHR equations. The validity and accuracy of the results obtained from the developed computer programs for both without and with chemical reaction were checked with Elgue [55] using the esterfication of acetic acid with methanol methyl acetate and water. The results obtained gave good agreement with accuracy 4.7% for maximum producing of methyl acetate at batch time 0.4hr, which are shown the programs in appendix B (B-1, B-2, and B-3). The influence of various parameters, such as number of stages, batch time, and liquid holdup upon the performance of the batch distillation column operating with chemical reaction were studied. Through vapor and liquid profiles, temperature profile,reaction rate profile, and liquid composition profiles.The results obtained for the non ideal reactive multistage batch distillation column show that the overall conversion to methyl- acetate is 49.41%, and the distillate composition is 24.7% for methyl acetate, with 90.7% recovery, when reflux ratio is 2.5,the number of stages is 6 theoretical stages with constant liquid holdup and batch time are 1.7hr. When decreasing the number of theoretical stages to 4 the mole fraction of methyl- acetate in the distillate decreased to 5% and the overall conversion becomes 10%. Increasing the number of theoretical stages to 8 the overall conversion to methyl- acetate is 5.1% with 10.2% conversion at batch time of 1.7hr. Decreasing the batch time to 1hr the distillation composition decreased to 22.5% with overall conversion of methyl- acetate of 45%, for 6 theoretical stages and 2.5 reflux ratio and constant holdup. Increasing the batch time to 3hrs the overall conversion becomes 43.4% and the mole fraction of methyl acetate decreased to 21.7%. The best design condition obtained from the present work was 1.7hr batch time, 6 theoretical of stages, 2.5 reflux ratio to give 90.7% recovery of methyl acetate and 49.41% overall conversion with constant liquid holdup through out the tower.Changing the liquid holdup throughout the tower will affect the performance of tower and increases the overall conversion to methyl acetate to 50.4% and the distillate composition to 25.2%.