Optimal Design, Proportional–Integral Control, and Model Predictive Control of Intensified Process for Formic Acid Production. 1. Reactive Distillation and Reactive Dividing Wall Column

• Published in: Industrial & engineering chemistry research Vol. 59; no. 51; pp. 22215 - 22230
• Main Authors: Ge, Xiaolong, Yang, Xinchuang, Han, Yicheng, Pan, Yu, Liu, Botan, Liu, Botong
• Format: Journal Article
• Language: English
• Published: American Chemical Society 23.12.2020
• Subjects: Process Systems Engineering
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/acs.iecr.0c04705

Formic acid production through methyl formate hydrolysis has been shown to be energy and capital cost intensive, and its performance could be significantly promoted by process intensification. However, integration of reaction and separation exhibits a complex nonlinear behavior, which requires corresponding optimization and control to be effectively addressed before further industrial implementation. In the present work, optimization was first performed for a conventional reactive distillation (RD) process and reactive dividing wall column (RDWC) by coupling genetic algorithm and rigorous simulations, in which a user-defined model was incorporated to take kinetics into account. Although the results demonstrate that RDWC is inferior to RD in terms of economic criteria, it provides the basis for proposing new easy-to-operate configurations in the subsequent part 2 of this series. Then multiloop proportional–integral (PI) control structures and linear model predictive control (MPC) schemes were designed for the conventional RD process and RDWC, respectively. The performances of two control structures were compared subject to feed disturbance, by using quantitative indexes such as oscillation, settling time, overshoot, and integral of the squared error (ISE). The dynamic response validates that MPC outperforms classical multiloop control schemes and could tackle the excessive overshoot deficiency in PI control for both the conventional RD process and RDWC.