Proposal Of A Process Intensification And Green Technology On Ethyl Acetate Production

Abstract

Although reactive distillation column is not a new concept, it has gained renewed interest in recent years as an effective way to pursue intensification of conventional chemical processes. Reactive distillation operations were first used by the chemical and petrochemical industry in esterification processes to separate reaction products from the reactants to increase product yields. Reactive distillation technology combines chemical synthesis steps with separations by distillation. This combination can lead to intensified, high-efficiency process systems with significant green engineering attributes. Among several approaches to process intensification are hybrid combinations of separation and reaction for chemical synthesis. These combinations offer new process alternatives that may have greatly improved efficiencies (e.g., in reduced energy requirements, lower solvent use, reduced equipment investment, and greater selectivity). Many of these potential advantages are intimately linked to the principles and challenges for green engineering. This work presents a study of establishment of a complete reactive distillation system for production of ethyl acetate via esterification of acetic acid with ethanol using ASPEN PLUS. Ethyl acetate is an important organic solvent widely used in the production of varnishes, ink, synthetic resins, and adhesive agents. Ethyl acetate is normally produced via reversible reaction of acetic acid with ethanol. There are only a few papers in the literature on the subject of the production of ethyl acetate via reactive distillation. A suitable NRTL (nonrandom two-liquid) model parameter set for calculating of liquid activity coefficients has been established with excellent prediction of the compositions and temperatures for the four azeotropes in the system. The predicted four azeotropes in this system include three homogeneous azeotropes of ethanol/ethyl acetate, ethanol/water and ethanol/ethyl acetate/water and also one heterogeneous azeotrope of ethyl acetate/water. A reactive distillation column with an overhead decanter can be designed to achieve over 93 wt% of ethyl acetate composition at organic phase top product stream while the bottom product stream is designed to be rich in acetic acid so that it can be recycled and mixed with fresh acid makeup stream to serve as acid feed to reactive distillation column. Since the purity of the optimum top organic product specification in industry, an additional column is designed to purify the ethyl acetate product of the reactive distillation column to over 99.5 wt%. The top draw of the second column will be recycled back to the decanter. Concluding, the process intensification of ethyl acetate production by reactive distillation was composed by two columns, including the reactive distillation column and the second column, one decanter, and two recycle streams. The optimum operating condition of the overall system will also be studied to minimize the total operating cost and the size of the plant wide of the overall system while meeting product specifications

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