Design, Optimization, and Retrofit of the Formic Acid Process I: Base Case Design and Dividing-Wall Column Retrofit

Formic acid (FA) is an important chemical with many applications in the industry. Despite this, the FA process has not received much attention in the open literature. In this work, FA process design and optimization are performed for the production of 98 wt % FA. Total annual cost (TAC) of the optimal base case process is 0.686 USD/kg. In addition, a recently developed methodology for process retrofit is applied, and retrofitting two distillation columns to a dividing-wall column (DWC) is investigated in detail. Results show that DWC retrofit is not attractive as it increases TAC of the process. The reasons for the increase in TAC are discussed. However, the FA process with DWC is attractive for a new plant, with lower capital and operating costs compared to the optimized base case process with conventional distillation columns.