Reactor development for a one‐step hybrid catalytic conversion of D‐glucose to HMF

Abstract The design of an “H”‐shaped reactor has been studied to satisfy the possibility of using a triphasic medium to transform d ‐glucose into 5 ‐hydroxymethylfurfural (HMF) by a hybrid catalytic process using an immobilized glucose isomerase, allowing the isomerization of D‐glucose to d ‐fructose, and a heterogeneous chemical catalyst to catalyze the dehydration of d ‐fructose to HMF. The various parameters influencing the transport of d ‐fructose within the reactor were studied, namely the difference in pH between the two aqueous phases, the agitation and the quantity of 3 , 4 ‐DCPBA/Aliquat336® used to extract and transport continuously the d ‐fructose. The pH discrepancy, which must be between 5.0 and 5.5, turns out to be the real driving force behind the extraction of D‐fructose. The D‐Fru/3,4‐DCPBA molar ratio of 1/0.25 allowed the transport of more than 80 % of the D‐fructose initially present and shows that the same molecule of 3,4‐DCPBA is involved at least twice in the transport of D‐fructose and that the 3 , 4 ‐DCPBA/Aliquat336® couple performs a turnover within the organic phase. Finally, a HMF production yield of 30.9 % and an isomerization yield of 79.1 % were obtained, illustrating the shift in the isomerization equilibrium made possible by a D‐fructose extraction yield of 96.8 %.