A separation process in which reaction and distillation occur simultaneously is called reactive-distillation. This process is potentially attractive whenever a liquid phase reaction must be carried out with a large excess of one reactant. In this study, two different types of examples were used. The first one is a typical example of the reactive-distillation which involves a reversible reaction for making ethyl acetate by esterification of acetic acid and ethanol. The second one involves an irreversible reaction for making 1-fluoro-1,1-chloroethane (HCFC-141b) and 1,1-difluoro-1-chloro ethane (HCFC-142b) by fluorination of methyl chloroform (MCF) of vinylidene chloride (VDC). The reactive-distillation equipment employs a reaction column for the esterification reaction but a reactor with reflux column for the MCF fluorination reaction. Reaction kinetics, vapor-liquid, and liquid-liquid equilibria which are required in designing and optimizing thereactive-distillation processes were measured experimentally and correlated using model equations. The effects of various operating conditions on conversion and yield were investigated by the simulation and the reactive-distillation experiments. I. The rate equation for esterification of acetic acid and ethanol in the presence of para-toluenesulfonic acid (PTSA) was obtained. The rate constant was correlated by a linear function of the catalyst concentration. The experimental data of the vapor-liquid equilibria with chemical reaction equilibrium of the quaternary system, acetic acid/ethanol/water/ethyl acetate, were correlated by using the modified UNIQUAC equation to satisfy the chemical equilibrium condition as well as the vapor-liquid equilibrium condition. In the reactive-distillation, the conversion of acetic acid was larger than 99% but that of ethanol, about 92%. The conversion of ethanol was above 95% in the simulation of the reactive-distillation column of 20 stages. The optimum reflux ratios for the light and heavy phases to maximize the conversion of acetic acid was found. II. The binary systems consisted of HCFC-142b, and MCF were close to ideal systems obeying Rault's law. The liquid-liquid equilibrium data of the ternary systems, HF/HCFC-141b/HCFC-142b, were measured at $20\circ\,C\!$ and $-20\circ\,C\!$, and correlated by NRTL equation. Heterogeneous azeotropic compositions in the systems containing HF were predicted by using NRTL parameters estimated from the solubility data at $-20\circ\,C\!$. The reaction of MCF and HF in the heterogeneous liquid phase was well described by second order reaction kinetics. The rate equation was obtained by assuming that liquid-liquid equilibrium was reached. The optium condition for HCFC-141b synthesis from MCF?(or VDC) and HF were as follows : HF/MCF mole ratio above 100, reaction temperature higher than 80$\circ\,C\!$, pressure 7-14 bar, and residence time 1-4 hr. In this condition, the conversion of MCF and VDC were above 90% and 98%, respectively. The effects of residence time and temperature on product compositions were predicted by the simplified model in which the reactive-distillation equipment is assumed to be a CSTR at the same reflux ratio of the inorganic phase. When the reactor was operated in excess of MCF, the conversion of MCF was greater than 99.5% and the selectivity of HCFC-141b, about 95%. The computer simulation predicted fairly well the product compositions for the preparation of HCFC-141b from MCF and HF. With decreasing the reflux ratio of the inorganic phase, the conversion of MCF and the HCFC-141b composition increased, but the HF/HCFC mole ratio in the reactor decreased. With larger liquid hold-up in the reflux column, the conversion of MCF could be obtained above 99.5%. When HF/MCF feed mole ratio was kept less than the minimum value that was calculated with a partial condenser, the conversion of MCF was reached 99.8% and the selectivity of HCFC-141b was larger than that for the excess of HF in this reactor, which agrees well with the experimental results.
