Reactive Distillation For Methy Acetate Synthesis With Ion Exchange Resin Catalysis

Reaction distillation is a kind of efficient intensifying process coupled together with reaction and separation, and it has characteristic with both physical phase change of transport phenomena of rectification tower, and chemical reaction mutual transformation phenomenon among reaction materials, two processes interacting with each other. Suiting for using the reaction distillation tower needs to meet the following two conditions:(1) the reversible reaction is the most appropriate, reactant leaving reaction system in a timely manner, deviating reaction equilibrium to positive constant, making the reaction more complete. In addition, it is best system if the reactants are the heaviest or the most light component, only in this way the products can be easily get from the top and bottom of the column;(2) separation of materials in reaction system is difficult, such as azeotropic or nearly boiling phenomenon, which can significantly improve the overall conversion rate of raw materials and reduce production energy consumption in the reaction distillation. The esterification of acetic acid and methanol for methyl acetate synthesis completely meet the above conditions.Strongly acidic cation exchange resin as the most concentrated alternative products of sulfuric acid has many advantages such as strong acid, security and environment friendly, so this paper selected strongly acidic cation exchange resin as catalyst for the esterification. Strongly acidic cationic exchange resin has the main exchange groups of sulfonic group(-SO3H), which the basement is the polymer of styrene as monomer and divinyl benzene as cross linking agent, after sulfonated with sulfuric acid to get resin material similar to benzene sulfonic acid, and the resin can be reused. This paper chooses two kinds of new type of strongly acidic cationic exchange resin-ILC-1 and ILC-2, investigating the catalytic esterification process of methanol with acetic acid to produce methyl acetate, and comparing catalytic properties of two kinds of ion exchange resin, and the best performer is led to more in-depth research.Kinetics of methyl acetate synthesis are determined by the experiments in a batch reactor at temperatures from 45 to 60 °C under atmospheric pressure, with molar ratio of reactants(θBo=nmethanol:nacetic acid) from 0.8 to 1.3. In a fixed bed reactor, the effect of the relationship between space time and conversion rate was also experimentalized. In this paper, NRTL, Wilson and UNIFAC model were studied for the non-ideal behavior of reactants. The kinetic data are correlated with the Q-H, E-R, and LHHW and pseudohomogeneous(P-H) models.The kinetic equation fitted by experimental data and the optimized thermodynamic methods input into the Aspen Plus software for catalytic esterification and reaction distillation column is simulated and calculated on the total number of plates of reactive distillation column, reflux ratio, feed location of the optimization.Based on results of optimization, a reactive distillation column was built in the laboratory. Due to the small particle size of the resin, which obviously can not be directly filled in the distillation column, resin filling way in the reaction distillation column was studied.In addition, the structure and properties of the resin were characterized by IR, XRD and optical microscopy in order to examine the structure, physical and chemical properties, acidity, deactivation and regeneration of the catalyst. Finally reactive distillation column has been designed for amplification.