(39g) Development and Economic Assessment of a Biphasic Process for 5-Hydroxymethylfurfural Production

5-hydroxymethylfurfural (HMF) is a value-added product with potential for upgrading to polymers, pharmaceuticals, and biofuels. Notably, HMF can serve as a direct, bio-based alternative to petroleum-derived terephthalic acid in the synthesis plastic bottles. Classically, HMF has been produced through fructose dehydration catalyzed by Brønsted acids, such as maleic acid. Our lab has previously demonstrated that the addition of Lewis acids, such as aluminum chloride (AlCl₃), to reaction mixtures allows the one-pot conversion of glucose to HMF, eliminating separate production of fructose from glucose. In this system, glucose is first isomerized to fructose, which is then dehydrated to HMF. However, due to low glucose conversion and product yields, this system is not industrially feasible. It is well known that dimethylsulfoxide (DMSO) and acetonitrile increase HMF yields from fructose by inhibiting side reactions. Here, we present a full kinetic analysis of HMF production from glucose using maleic acid and AlCl₃ as catalysts in water:co-solvent mixtures. Notably, acetonitrile (40% v/v) significantly increases glucose isomerization, while DMSO (20% v/v) doubles the rate of fructose dehydration and inhibits HMF degradation. The combined action of DMSO and acetonitrile drastically shifts the reaction kinetics towards HMF production. Combining DMSO and acetonitrile in this reaction media increases molar yields from 18% to 30%. However, issues with HMF stability drastically limit yields greater than 30%. Stability issues are overcome through addition of activated carbon to create a biphasic system, increasing molar HMF yields to 67% at the 2 ml scale. At 30 ml scale, HMF yields of 56% are achievable. Preliminary design of an industrial facility capable of producing 170,000 tonnes of HMF annually has a minimum HMF selling price of ~$0.60 lb^-1. This is comparable to current terephthalic acid prices of ~$0.50 lb^-1. Our demonstrated process yields combined with a robust techno-economic analysis provides a roadmap for achieving economically competitive HMF from biomass-derived glucose.