Cellulose dissolution and conversion into 5-hydroxymethylfurfural in mixed molten salt hydrate

Molten salt hydrate (MSH) is a good solvent for cellulose dissolution and an effective catalyst for cellulose conversion. In this work, a series of MSH was evaluated in terms of cellulose dissolvability, regeneration performance, and catalytic activity in cellulose conversion into 5-hydroxymethylfurfural (HMF). ZnBr2 center dot 3H(2)O-LiCl center dot 3H(2)O showed good performance on cellulose dissolution and conversion. The effects of ZnBr2 center dot 3H(2)O concentration, reaction temperature, and time on cellulose conversion into HMF in ZnBr2 center dot 3H(2)O-LiCl center dot 3H(2)O were optimized, and 48.7% HMF yield was reached at 60 wt.% ZnBr2 center dot 3H(2)O. The species of ZnBr2 center dot 3H(2)O-LiCl center dot 3H(2)O were analyzed, and the function of species concentration was correlated with the product yield from the conversion of fructose. It was found that Br- and H+ were the active species for fructose dehydration into HMF. ZnBr3- and H+ catalyzed the conversion of fructose into furfural, which competed with the production of HMF. The reaction mechanism was proposed to understand the cooperate of species in MSH for cellulose conversion.

Automated summary

In this study, a series of molten salt hydrates (MSH) were evaluated for their ability to dissolve cellulose and catalyze its conversion into 5-hydroxymethylfurfural (HMF). ZnBr2 center dot 3H(2)O-LiCl center dot 3H(2)O showed good performance in cellulose dissolution and conversion. By optimizing the concentration of ZnBr2 center dot 3H(2)O, reaction temperature, and time, a maximum HMF yield of 48.7% was achieved. The species present in ZnBr2 center dot 3H(2)O-LiCl center dot 3H(2)O were analyzed, and it was found that Br- and H+ were the active species for fructose dehydration into HMF. ZnBr3- and H+ catalyzed the conversion of fructose into furfural, competing with HMF production. The proposed reaction mechanism provides insight into the cooperative role of species in MSH for cellulose conversion.