A Systematic Method for the Development of Operating Policies for Two-Step Processes with Semibatch Reactive Distillation
Journal
Industrial and Engineering Chemistry Research
Journal Volume
55
Journal Issue
31
Pages
8602-8615
Date Issued
2016
Author(s)
Abstract
Semibatch reactive distillation (SBRD) is a variation on batch reactive distillation (BRD) in which one reactant or an entrainer is fed to the process continuously during the batch. Qi and Malone (Qi, W; Malone, M. F. Semibatch Reactive Distillation for Isopropyl Acetate Synthesis. Ind. Eng. Chem. Res. 2011, 50, 1272-1277) suggested SBRD for the synthesis of isopropyl acetate with acetic acid fed continuously at the top of the column to reduce the composition of the alcohol in the distillate product. The distillate product from the SBRD is a mixture of water and ester which can subsequently be separated by inverted batch distillation (IBD). The optimization of such a two-step batch process involves trade-offs between the two steps (SBRD and IBD). In this work, an algorithm for systematic design of such processes is developed and applied to processes for the synthesis of isopropyl acetate and ethyl acetate. The key variable connecting the two batch steps is the composition of alcohol in the SBRD distillate product. Allowing a higher alcohol composition makes SBRD operation easier but IBD operation more difficult. The algorithm identifies the alcohol concentration which minimizes total process time, which is closely related to energy consumption, as well as side feed flow rate and reflux ratio profiles during the batches. ? 2016 American Chemical Society.
Other Subjects
Batch data processing; Economic and social effects; Energy utilization; Optimization; Alcohol concentrations; Batch distillation; Isopropyl acetate; Operating policies; Reactive distillations; Systematic designs; Systematic method; Two-step process; Distillation
Type
journal article