Technology Profile: Acetic Acid Production from Methanol
By Intratec Solutions |
This column is based on “Acetic Acid Production from Methanol – Cost Analysis,” a report published by Intratec. It can be found at: www.intratec.us/analysis/acetic-acid-production-cost.
Acetic acid (also known as ethanoic acid) is a carboxylic acid found as dilute solutions in plant and animal systems. Industrially, the chemical is widely used in organic processes, primarily in the production of vinyl acetate monomer and acetic anhydride.
The following paragraphs describe a process for producing acetic acid from methanol and carbon monoxide, based on rhodium-catalyzed carbonylation. Figure 1 presents a simplified flow diagram of the process.
Figure 1. The diagram shows a typical rhodium-catalyzed carbonylation process for acetic acid production[/caption]
Catalyst preparation. Initially, recycled rhodium catalyst is treated to recover the rhodium. The treated catalyst is mixed with fresh catalyst, a promoter (methyl iodide) and a stabilizer (iodide salt). The mixture is then dissolved in hot acetic acid under pressurized carbon monoxide.
Carbonylation. The reactor is fed with the catalyst solution, methanol and carbon monoxide, along with recycle streams. The reaction occurs in the liquid phase, where dissolved…