Design and Control of Thermally Coupled Reactive Distillation for the Production of Isopropyl Acetate

Isopropyl acetates are important organic solvents that are widely used in the production of varnishes, ink, synthetic resins, and adhesive agents. Previous studies developed a process for the production of isopropyl acetate incorporating a reactive distillation (RD) column, a decanter, and a stripper. According to the previous study, the rectifying section of the RD column has a prominent remixing phenomenon. Furthermore, the overhead compositions of RD column and the stripper are all within the liquid–liquid equilibrium envelope. Based on the above observations, a thermally coupled design of this process is established. The key points in the thermally coupled design are: to move the location of the decanter to the stripper side, to totally reflux the organic phase outlet stream, and to sidedraw a liquid stream from the stripper to the RD column. Simulation result shows that 23.14% energy savings can be realized using the proposed thermally coupled design. The control strategy of the proposed design flowsheet is also investigated using tray temperature control loops to indirectly control the product composition. The proposed control strategy is capable of maintaining high-purity product, despite changes in feed composition and throughput.