Biomass-based production of trimellitic and trimesic acids

The production of industrial chemicals with renewable biomass feedstock holds potential to aid the world in pursuing a carbon-neutral society. Trimellitic and trimesic acids are important commodity chemicals in industry that are prepared by the oxidation of petroleum-derived trimethylbenzene. To reduce the dependence on the limited oil source, we develop a potential sustainable alternative towards trimellitic and trimesic acids using biomass-based 2-methyl-2,4-pentandiol (MPD), acrylate and crotonaldehyde as starting materials. The process for trimellitic acid includes dehydration/D-A reaction of MPD and acrylate, flow aromatization over Pd/C catalyst, hydrolysis and catalytic aerobic oxidation (60% overall yield). The challenging regioselectivity issue of D-A reaction is tackled by a matched combination of temperature and deep eutectic solvent ChCl/HCO 2 H. Crotonaldehyde can also participate in the reaction, followed by Pd/C-catalyzed decarbonylation/dehydrogenation and oxidation to provide trimesic acid in 54% overall yield. Life cycle assessment implies that compared to conventional fossil process, our biomass-based routes present a potential in reducing carbon emissions . (c) 2023 Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).