5-Hydroximethylfurfural production from fructose/Isopropanol mixtures with sulfonic resins as catalyst in a continuous flow reactor

G.L. PESTANA; L. PIERANTONI; J.M. GRAU

Santa Fe

Workshop; French-Argentinian Workshop on Heterogeneous Catalysis; 2023

INCAPE - SACAT

The 5-hydroximethylfurfural (HMF) it’s a platform compound for the synthesis of liquid biofuels like 2,5-Dimethylfuran (DMF) or 5-Etoximethylfurfural (EMF). Biomass is the only renewable and abundantly available sustainable carbon resource. Glucose from ligno- cellulosic biomass can be easily isomerized to fructose whose dehydration produces HMF using acid catalysts. A wide variety of acid catalysts have been studied for these reactions in biphasic water/organic solvent systems and in batch reactors. Although some propose continuous reactors, they do not consider the feasibility of a future industrial scale-up due to the costs and toxicity of catalysts and solvents. Besides in aqueous acid environment the carbohydrates and its derivatives produce a wide range of by products that diminish the yield and selectivity. In this work we compare the behavior of two simple cationic ion exchange resins in a continuous flow reactor with a WHSV of 3.1 h-1 at 120°C using 45 g/L fructose in isopropanol for 240 min. The best of them maintains a yield and selectivity to HMF of 57.6% and 62.2% respectively at steady state, with a fructose conversion of 99.7%. A high acidity in the resin can produce deactivation by degradation of fructose, HMF or by-products by deposition of humins, decreasing the yield of HMF. The (RII/M)-H+ resin has shown the highest production of HMF and a stable behavior over time due to its adequate acidity. Isopropanol is a suitable solvent to stabilize the reaction product. This resin/solvent system will be used to optimize operating conditions seeking an expansion of the process.