Study On The New Process Of Catalytic Distillation Of Methyl Acetate Hydrolysis And Related Fundamental Research

Based on the success of the industrialization of the process of catalytic distillation of methyl acetate hydrolysis, the new process of catalytic distillation of methyl acetate and methanol azeotrope hydrolysis and related fundamental research were studied. These can make further improvement on the process in order to simplify the process and reduce the energy-consumed of the recovery system. In addition, theoretical system of the simulation and design the catalytic distillation process were established, which can provide the basis of the pilot plant and industrialization in the future. The main works were as follows:1. The experiments were carried out in a column of 25mm in diameter, and the large quantity of experimental data and satisfactory results were obtained. The results demonstrate that optimal technological conditions are as follows: methyl acetate and methanol azeotrope fed from the top of reactive section, space velocity was 0.356, molar ratio of water-methyl acetate was 5.0 and ratio of reflux to feed was 2.15. Under the optimal operational conditions, the conversion of ester could reach 80.38% and the energy consumption of recovery system was lower by 39.99% than conventional fixed bed reactor technology, by 23.5% than catalytic distillation technology. Based on the scale of 33 thousands ton of PVA per year, the economic benefit could reach 9.425 million yuan per year. Therefore, the industrialization of new technology will obtain greater economic and social benefit. 2. The kinetics of the hydrolysis of methyl acetate was measured in a batch stirred reactor with SK-1A cation exchange resin as catalyst, and the kinetic equation based on the per catalyst quality for describing the hydrolysis of methyl acetate could be expressed aswhere These can provide necessary data for the simulation and calculation of the process of catalytic distillation hydrolysis of methyl acetate.3. LLE(liquid-liquid equilibrium) data have been determined in the LLE still for the quaternary system of methyl acetate-methanol-water-acetic acid, the related ternary system of methyl acetate-methanol-water and methyl acetate-water-acetic acid, and the related methyl acetate-water binary system at 20℃,30℃,40℃ and 50℃ under atmospheric pressure. These works can provide sufficient data support for industry design and add new LLE data into the data bank. The experimental data have been correlated by the activity coefficient models including NRTL and UNIQUAC. And the model parameters were gained by simplex optimization and the comparison between calculated and experimental data shows good agreement. In addition, the software of LLE correlation and prediction was developed by Visual Basic 6.0, which can correlate and calculate LLE data conveniently.4. A stable convergence calculation method using Newton homotopy continuation method based on the non-equilibrium rate model was established. It was used to simulate the catalytic distillation column of methyl acetate and methanol azeotrope hydrolysis combined with the macro-dynamic equation of methyl acetate hydrolysis. The facts of rapid convergence from any one starting point show that the algorithm is more robust. It was concluded from the calculation that the results were satisfactory and the ratio of reflux to methyl acetate feed had less influence on the conversion of methyl acetate. It is good guide to the pilot experiment, and can provide the basis for the industrial design.