Study on Hydrolysis of Methyl Acetate in a Catalytic Distillation Column

A nonequilibrium stage model was used to simulate countercurrent multicomponent catalytic distillation processes for methyl acetate hydrolysis. Computations of stage efficiencies or height equivalent to a theoretical plate (HETP) were entirely avoided by this model. The consistency of simulated results and experimental data in conversions and concentration of each component along a column indicates that the model predicts the actual process well. The influences of operating parameters on hydrolytic conversions, such as feed molar ratios, feed locations, feed and reflux rates, heights of reactive and stripping sections, were analyzed adequately by simulating calculations. A good operating mode was then obtained, which is helpful to the development of a new process.

Simulation of Continuous Esterification Process of Polyester Polyols

Based on the kinetic and thermodynamic equations, a comprehensive mathematical model for the con- tinuous esterification process of polyester polyols was developed, which was carried out in an innovational bub- bling reactive distillation tower （BRDT） at atmospheric pressure. In this new type of reactor, direct esterification between ethylene glycol and adipic acid was accomplished efficiently and rapidly. A bench BRDT with the height of 2 m was applied for the esteriflcation process of l^oly （ethylene adlpate） （P＇EA）. In the continuous operation, Hn- ear oligomers were discharged from the bottom of the column, while water passed a few column trays and a pack- ing section as a condensation byproduct. The influence of major operating conditions on reactor performance was also simulated. Simulation results were in good agreement with experimental data, providing a strategy for devel- oping and optimizing this process.

The Modeling and Simulation of Reactive Distillation for the Esterification Process

In this paper,a generalized model of the reactive distillation processes was developed via rate-based approach. The homotopy-continuation method was employed to solve the complicated nonlinear model equations efficiently. The simulation on the reactive distillation processes was carried out with the profiles of stage temperature,composition and flow rate for both vapor and liquid phases obtained. Based on careful analysis of the simulation results, the pitfalls in experimental design were detected. Finally, a software package for the simulation of reactive distillation processes was developed.

Kinetic Modeling of Esterification Reaction of Free Fatty Acids Present in Macauba Oil Using a Cationic Resin as Catalyst

The cost of raw materials has the largest contribution to the final price of biodiesel produced by traditional routes, currently adopted in most industrial scale processes. That contribution comes from the need to use edible and noble oils, with low acidity, such as soybean oil. This work proposes＇the use of Macauba oil, a vegetable oil in focus in the State of Minas Gerais, Brazil, in which the current extractive yield generates a raw material with high acidity, therefore, not suitable to be used in biodiesel production. To make it technically feasible, a cationic exchange resin, the Purolite CT275DR, was used as a catalyst for esterification reaction with samples of Macauba oil, aiming to reduce its acidity. The resin can be reused, regenerated and easily removed from the reaction product, reducing costs with catalyst and purification stages. As a result of this work, in a sample of oil with an initial acidity of about 10% m/m were achieved acidity reductions up to 97% by using cationic resins as catalyst, demonstrating its potential use in the oil pretreatrnent step. Additionally, the data collected during all the analysis made it possible to define the chemical kinetic of the esterification reaction.

水性环氧树脂研究进展

本文介绍了环氧树脂水性化的研究进展 。