Plantwide Control of the Formic Acid Production Process Using an Integrated Framework of Simulation and Heuristics

Abstract

Formic acid (FA) is an essential chemical, but its process design and control have not received much attention in the literature. This contribution describes the design of a plantwide control (PWC) structure for the intricate FA process having reactive distillation (RD), multiple liquid and gas recycles, as well as a snowballing effect. In this process, methyl formate (MF) is produced from methanol (MA) and carbon monoxide (CO), and then it undergoes a hydrolysis reaction in RD to produce FA and also MA for the first reaction. The presence of an RD in addition to a continuous stirred tank reactor (CSTR) coupled with three recycles makes control of the FA process interesting and challenging. This work employs a systematic method for PWC design, namely, an integrated framework of simulation and heuristics (IFSH), which is easy to implement and uses process simulators as well as heuristics in PWC design. The performance of the developed PWC structure was evaluated for various disturbances, using several criteria recommended for the evaluation of PWC design. Results of dynamic simulations and these performance evaluations show that the proposed PWC system is able to reject the tested disturbances efficiently, while meeting FA purity and production requirements. PWC for the two-step complex FA process is studied for the first time in this contribution.

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

“…The RDWC is the only attractive retrofit choice with a molar ratio between water and MF of 5.98 by taking heat integration into account. Besides, they used an empirical and hierarchical strategy to develop a plantwide control structure by incorporating RD retrofit for MF hydrolysis, 36 which was shown to be effective to handle feed disturbance and components accumulation in the entire process. Novita et al 37 proposed eight intensified retrofits and concluded that DWC with heat integration is the most energy efficient with F water :F MF as 2.1:1.…”