Conversion Of Cellulose To 5-Hydroxylmethylfurfural In Biphasic System

Cellulose, the largest output biomass in nature, is drawing a lot of attention in recent years.5-Hydroxymethylfurfural (5-HMF), which can be produced from cellulose, is regarded one of the key petrochemicals and biofuels intermediatesas. In order to realize industrial production for 5-HMF form cellulose, efficient catalytic system must be designed. It was found that both generation of 5-HMF and preliminary separation of 5-HMF were integrated by biphasic system simultaneously, and thus favors the improvement of the reaction selectivity of cellulose and increasing the efficiency of 5-HMF. Sulfonic acid functionalized ionic liquids have the dual advantages of solid acid and liquid acid, which are becoming a new hotspot. This paper presents the works on degradation of cellulose to 5-HMF catalyzed sulfonic acid functionalized ionic liquids and sulphates in the water-tetrahydrofuran (H2O-THF) biphasic systemIn this paper, 1-(3-sulfonic acid) propylpyridinium dihydrogen phosphate ([PSPy][H2PO4]), 1-(3-sulfonic acid) propylimidazolium toluenesulfonate ([PSmim][p-TSA]), 1-(3-sulfonic acid) propylimidazolium hydrogen sulfate ([PSmim][HSO4]), 1-(3-sulfonic acid) propyltriethylaminium hydrogen sulfate ([PSTEA][HSO4]), 1-(3-sulfonic acid) propylpyridinium hydrogen sulfate ([PSPy][HSO4]), were synthesized and characterized by1H-NMR. Production of 5-hydroxymethylfurfural (5-HMF) from microcrystalline cellulose (MCC) was studied in SO3H-functionalized ionic liquids-H2O/THF biphasic system. The effects of various reaction parameters such as catalyst type, acidity, catalyst dosage, reaction temperature and reaction time were investigated. It is found that the strong acidity and the structure of SO3H-functionalized ionic liquids play key roles in promoting the conversion of cellulose into 5-HMF, and [PSPY]HSO4 gives the best results.Production of 5-hydroxymethylfurfural (HMF) from microcrystalline cellulose (MCC) was studied in 1-(3-sulfonicacid)-propyl-3-methylimidazolium hydrogen sulfate ([PSMIM]HSO4)-H2O/THF biphasic system with catalytic amount of ZnSO4 · 7H2O. The effects of various reaction parameters such as catalyst dosage, reaction temperature and water content were investigated. The highest HMF yield of 58.8% and TRS yield of 64.8% were obtained at 160 ℃ for only 60 min by [PSMIM]HSO4 and ZnSO4 ·7H2O co-catalyst. After being separated from the organic phase, the aqueous phase could be reused and demonstrated stable activity after four successive runs. A mechanism was proposed to explain the high activity of ZnSO4·7H2O and [PSMIM]HSO4.