(682g) High Yield of Succinic Acid Production through Deoxydehydration/Hydrodeoxygenation Reactions of Tartaric Acid

Currently, fossil fuels represent the main source of energy, fuels and commodity chemicals production. However, escalating concerns about greenhouse gases emitted to the atmosphere due to the utilization of fossil fuels, as well as the depletion of these resources, urged for the discovery and development of environmentally benign processes to produce fuels and chemical building blocks from renewable resources.¹ Succinic acid is a four-carbon dicarboxylic acid, that has been recognized as one of the top biomass-derived chemical building blocks by the Department of Energy.² It is mainly produced through petrochemical routes, and more recently biochemical routes through the fermentation of glucose. Although, the fermentation route has been industrialized in many countries now, it suffers from major drawbacks, ranging from low productivity, expensive nutrient requirements, high pH values and many organic acid side products.

A novel thermochemical catalytic on-step process to produce succinic acid from tartaric acid (main constituent in winery waste stream), has been recently proposed.³ Despite the remarkable yield of succinic acid (87%) the total carbon balance of the reaction was low. Moreover, the proposed catalyst requires pretreatment, and the reaction mixture needs initiators (HBr and acetic acid) to activate the C-O bond cleavage. Further development of this process is necessary for it to penetrate the market.

Herein, we present our recent findings in producing succinic acid starting from tartaric acid with 97% yield in a batch reactor setup. The process was achieved by utilizing a bifunctional heterogenous catalyst supported on reducible metal oxide, and molecular hydrogen as the reductant. The bimetallic catalyst is retarded against the terminal carboxylic acid groups and can selectively produce succinic acid through two reaction pathways. The first, is the deoxydehydration (DODH) of tartaric acid to produce fumaric acid, followed by the hydrogenation of the C=C bond to succinic acid. While the second pathway, is a sequential hydrodeoxygenation (HDO) to malic acid intermediate then to the final desired product.

References:

(1) Corma, A.; Iborra, S.; Velty, A. Chemical reviews 2007, 107, 2411.

(2) Werpy, T.; Petersen, G. Top value added chemicals from biomass: volume I--results of screening for potential candidates from sugars and synthesis gas, National Renewable Energy Lab., Golden, CO (US), 2004.

(3) Fu, J.; Vasiliadou, E. S.; Goulas, K. A.; Saha, B.; Vlachos, D. G. Catalysis Science & Technology 2017, 7, 4944.