Novel dehydration of carbohydrates to 5-hydroxymethylfurfural catalyzed by Ir and Au chlorides in ionic liquids

Production of 5-hydroxymethylfurfural in a eutectic mixture of citric acid and choline chloride and its extractive recovery

“…There are many reports focusing on the optimization of the conditions such as the type of ILs and catalysts for HMF preparation in order to obtain high yields and high concentrations of HMF [12][13][14][15][16][17][18][19][20][21][22]. However, the number of studies primarily focusing on the kinetics of the formation of HMF in ILs is limited [13,14,18,19], and knowledge of the kinetics is presently insufficient to adequately predict the formation of HMF.…”

“…However, the number of studies primarily focusing on the kinetics of the formation of HMF in ILs is limited [13,14,18,19], and knowledge of the kinetics is presently insufficient to adequately predict the formation of HMF.…”

“…Moreover, the extractive recovery of HMF from an IL has been performed using organic solvents such as ethyl acetate [13][14][15][16]23], tetrahydrofuran (THF) [24,25], methyl isobutyl ketone (MIBK) [26], and diethyl ether [27,28]. In the extraction process, water is often added to the reaction mixture prior to extraction to improve the extraction efficiency [14][15][16].…”

“…In the extraction process, water is often added to the reaction mixture prior to extraction to improve the extraction efficiency [14][15][16]. Subsequently, an organic solvent is added to recover HMF．It is necessary to remove the added water from the ILs in order to reuse them, but the process of water removal involves high energy consumption.…”

Efficient Dehydration of Fructose to 5-Hydroxy-methylfurfural Catalyzed by Heteropolyacid Salts

“…Mineral acids (H 2 SO 4 , HCl and HNO 3 ) and transition metal salts have been widely used in the production of 5-HMF [15][16][17][18][19]. However, the homogeneous methods suffers from complicated separation processes especially considering the regeneration of the system.…”