Reactive Distillation for Esterification of an Alcohol Mixture Containing n-Butanol and n-Amyl Alcohol

Abstract

Manufacturing processes in the semiconductor and pharmaceutical industries often produce alcohol mixture byproducts. Therefore, the esterification of alcohol mixtures may be an important step in reusing wastes from these industries. There are two alternative methods for using the alcohol mixtures as feed for reactive distillation (RD). The first method separates this mixture into pure alcohols first and then follows with esterification using the RD column. The second method uses direct esterification of the alcohol mixture in a RD column, and then separates the mixed-ester products. This paper discusses the esterification of a n-butanol (BuOH) and n-amyl alcohol (AmOH) mixture with acetic acid (HAc). This study presents two important results based on optimizing the total annual cost (TAC). First, the mixed BuOH/AmOH system, with direct esterification with RD followed by product separation, is more economical than the system that first separates the mixture. Second, this study proposes a novel economical indirect-sequence design flowsheet with aqueous reflux. Another important issue in this study is the choice of the relative feed location, because the boiling point of acid lies between that of the two alcohols (i.e., BuOH < HAc < AmOH). Reaction kinetics is an important factor to be considered in determining the feed location of the alcohol mixture.

Kinetic study of catalytic esterification of butyric acid and n-butanol over Dowex 50Wx8-400

“…The reactive distillation method is known as a pertinent reacting system to solve the limitations resulting from the existence of unfavorable byproducts. This system is a combination of a reversible reaction and distillation, and provides the conversion of reactants higher than equilibrium conversion via the removal of water during esterification [3][4][5][6][7][8][9]. In addition, the reactive distillation has a merit in the sense that, since the distillation separates the undesirable products (water in the case of esterification reaction) from the products in the course of reaction, the need for additional separation unit is obviated.…”

“…Meanwhile, the research on the esterification of acetic acid with propyl alcohol over heterogeneous catalyst, Dowex MONOSPHERE 650 C, has been reported [16], where the reaction mechanism was presented, and kinetic and thermodynamic parameters were calculated. The investigation of the kinetics for the esterification reaction on the basis of experimental data obtained in the reactive distillation system has been widely reported in the literature [4][5][6][7][8][9], and many illustrative research works can be referred to Schmitt and coworkers' work [6]. In spite of many reports on the esterification with heterogeneous catalysts, however, a few kinetic studies consider the steps between ion exchange resins and liquid reactants/products.…”

Coproduction of Ethyl Acetate and n‐Butyl Acetate by Using a Reactive Dividing‐Wall Column

“…Because of the nonideal VLE, vapor‐liquid‐liquid equilibrium (VLLE), and dimerization of carboxylic species for this mixed‐alcohol esterification system, the nonrandom two‐liquid Hayden‐O'Connell (NRTL‐HOC) activity coefficient model is adopted to calculate the activity coefficient in the liquid phase . The NRTL‐HOC parameters are obtained from , , and the partial model equation is from the Aspen Plus user manual 11.1. The Aspen Plus built‐in association parameters are used to compute the fugacity coefficients.…”

Rigorous design and control of thermally integrated pressure‐swing reactive distillation process for isobutyl acetate production considering the effect of column pressures

“…As a typical process intensification technology, RD has gained significant attention recently. [1][2][3][4][5][6][7][8][9][10][11][12] It is typically operated in two modes: excess reactant feed (twocolumn process) and neat operation (single-column process). Luyben [13] quantitatively compared the steadystate economics and the dynamic controllability of two alternative RD systems, and the results show that the single-column process has better steady-state economics, while the two-column process exhibits adequate dynamic controllability.…”