Simulation And Optimization Of Preparation Of N - Butyl Acetate By Reactive Distillation Column

N-butyl acetate is an important raw material in pharmaceutical, chemical, spices and other industries, with more and more inereasing industrial demand. At present, the main method of the synthesis processes is via esterification of acetic acid and n-butanol in the current domestic industrial production. Its catalyst was sulfuric acid. And its problems have a greater consumption of raw materials, low product purity, high energy consumption, equipment perishable, the subsequent step of separating the difficulties, the spent acid emissions pollute the environment. For the shortcomings of the above process, domestic and foreign researchers developed a synthesis process of a series of reactive distillation technology, in which the two main production process:the acetate discharge from the bottom type and the acetate discharge from the tower type. However, reactive distillation technology still have some shortcomings:the middle component easily backmixing phenomenon in the tower, which makes the product purity and equipment energy consumption are affected.In this paper, in order to solve these problems, these two technologies were transformed with reactive dividing-wall column technology, and were modeled and analyzed. First introduced the reactive dividing-wall column species and configuration, analysising the principle and corresponding the design method for each type. In this method, models regarding two kinds of reactive distillation are established using Aspen Plus software. The two kinds of process for reactive dividing-wall column, in which the acetate discharge from the bottom and top separately, were established on the basis of two corresponding reactive distillation process. Using two-column model to calculate for two types process. Their results with the conventional reactive distillation process are compared:They saved27.78%and27.97%of the energy consumption respectively, and analyzed its energy-saving reasons. Then the two kinds of reactive dividing-wall column were compared, they had the same molar purity of n-butyl acetate product. But the former less than the latter about four times of energy consumption. So the most advantageous process is the reactive dividing-wall column of the acetate discharge from the bottom.The reactive dividing-wall column was optimized in the the acetate discharge from the bottom type. Based on the two-column model, three-column model was established. Using the steady-state model, the optimized value of every parameter had been determined for the higher product profit. And the optimum process parameters were determined as follows:The number of rectifying section, reaction section stripping section and public stripping section were7,12,1and7, separately; the molar ratio of acetic acid to n-butanol was1:1;Their feed location were in the eighth and eleventh tray, separately; vapor split ratio and reflux ratio were0.2and0.9, separately. Finally, the before and after process optimization were compared. By comparison, the reactive dividing-wall column had higher product purity, higher energy efficiency and lower investment in equipment at the optimal value.