Microreactor Process for the Optimized Synthesis of 5‐Hydroxymethylfurfural: A Promising Building Block Obtained by Catalytic Dehydration of Fructose

Abstract

A continuous microreaction process was set up to analyze and improve the "green" synthesis of 5-hydroxymethylfurfural (5-HMF) based oil the HCl-catalyzed dehydration of fructose in pure aqueous solutions. The process conditions were deliberately shifted to high temperatures and pressures (185 degrees C, 17 bar) and combined with a reduced reaction time of only 1 min to avoid extensive rehydration of the product. 5-HMF was obtained with 75 % selectivity and 54 % yield at 71 % fructose conversion. In comparison to published data, a 24 % increase in selectivity and a 21 % increase in conversion could be achieved. Moreover, by adding organic co-solvents and extraction agents to the reaction system, both 5-HMF selectivity and yield could be further enhanced to 85 and 82 %, respectively. However, the use of additional organic solvents cannot be considered as a green process anymore

Simplified Model for Extraction of 5-Hydroxymethylfurfural from Fructose: Use of Water/Oil Biphasic System under High Temperature and Pressure Conditions

“…Recently, the efficacy of a microreactor for HMF production has been investigated [5]. Of the microreactors, a capillary microreactor is considered to be a promising system because the surface-to-volume ratio of the liquid-liquid biphasic system can be increased by the generation of slug flow in the capillary through a Y-or T-junction [12,13].…”

“…5-Hydroxymethylfurfural (HMF) is one of the many potential platform chemicals for biorenewable chemicals production [1] because it is formed by dehydration of xylose, fructose and glucose [2][3][4][5].…”

Water / Methyl isobutyl ketone (MIBK) Biphasic System in Slug Flow under High Temperature and Pressure Conditions

“…Recently, treatments of biomass have been studied for the development of green processes to recover value-added materials such as 5-hdroxymethylfurfural (HMF) [1][2][3][4][5], 2,5-furandicarbocylic acid (FDCA) [6], lactic acid [7,8], and others. For examples, a variety of recovery methods using the acid-induced production of HMF [1,3], the microwave-assisted hydrothermal degradation [9], or the heterogeneous catalyst such as ytterbium triflate [10], zeolite [11], and zirconium [12], have been reported.…”

Zeolite Catalysis for Biomass Conversion

“…Apart from mineral acids such as HCl or H 2 SO 4 [ 60 ], also solid acids such as sulfonated resins ( e.g. , Amberlyst) [ 61 ], sulfonated organosilica [ 61 , 62 ] and Brønsted acidic zeolites [ 63 , 64 ] can readily convert fructose to HMF.…”