New Dehydration Process To Prepare Anhydrous Alcohol With Azeotropic Distillation

Anhydrous alcohol is one kind of excellent organic solvents which was widely used in pharmaceutical and painting manufacture. Traditionally, there are several way to prepare anhydrous alcohol, such as molecular sieve dehydration, azeotropic distillation, membrane separation etc. To produce anhydrous alcohol by using azeotropic distillation have lots of merits such as continuous operation, less investment, lower energy consumption, high purity of product and so on. now It is the most popular process in anhydrous alcohol preparation. But in practical azeotropic distillation operations, a small fluctuation of operation process parameter may have great effect to the distillation's stability which would make the azeotropic point deflected and break the working conditions of azeotropy required. During prepare anhydrous alcohol by azeotropic distillation by changing the upper part of azeotropic distillation column into a rectifying section with partially condensation section. And filled with usual packings. It has a great benefits such as reflux ratio automatic regulation, quickly response of controlling, lower energy consumption etc. the operation elasticity of azeotropic distillation column can obviously be improved.In this article, by using Visual C++ programming, simulations of ethanol-water-benzene azeotropic distillation column was carried out. By setting the feed stream flow rate as 100Kg/hr of 95.57%(wt) ethanol. After running the simulations, distillate rate at 69Kg/hr, benzene phase reflux at 58Kg/hr and reflux ratio at 3 can be achieved as the optimal operation parameters, and the higher concentration of feed ethanol, the higher concentration product we got. Besides, the four parameters' sensibility were analyzed, result showed that the concentration of feed stream and benzene phase reflux have larger sensibility while heating load and reflux ratio have smaller sensibility. A pilot column with DN100 and with 2.8m height was designed and manufactured based on these simulation data, and then experiments were carry out in lined with the simulation conditions. Under optimal operate condition, product drawn from bottom can reach at 99%(wt) and above. In the experiments, partially condensation section of the column can automatically adjust reflux ratio, So it can remarkably improve the operation stability, the three phase azeotropic point can be stably sustained at 64.85℃ on the top. that is consistent with the theory analyze.