Continuous 5-Hydroxymethylfurfural Production from Monosaccharides in a Microreactor

Abstract

5-Hydroxymethylfurfural (HMF) was effectively produced from monosaccharides in a microreactor. A biphasic reaction system was employed to achieve the immediate extraction of produced HMF and suppress the overreaction. A microreactor was utilized to ensure that the reaction occurred under segmented flow to enhance the extraction efficiency. Through many attempts using phosphate buffer saline (PBS) as the reaction phase and 2-sec-butyl phenol (2BP) as the extraction phase, the favorable conditions were determined. By using PBS with pH of 2.0 and 2BP at a volume ratio of 3 to PBS, 80.9 mol % of fructose and 75.7 mol % of glucose were converted into HMF, respectively, at 180 °C. By comparing the results obtained through monophasic reactions, it was confirmed that the biphasic system successfully suppressed both the overreaction and the byproducts. The system employed only a simple experimental apparatus and the acid solution and organic solvent reagents without any complex expensive catalyst.

Catalytic Transformation of Biomass Derivatives to Value‐Added Chemicals and Fuels in Continuous Flow Microreactors

“…Due to the strong shear force generated by centrifugal forces in the CCCS, liquid-liquid mixing is enhanced considerably, accelerating reactions with fast kinetics that are limited by mass transfer. [134] Typically, microreactors have been used for single liquid phase and biphasic (gas-liquid or liquid-liquid) catalytic transformation of biomass derivatives to valuable products using homogeneous or heterogeneous catalysts (e. g., the (biphasic) synthesis of furans from sugars, [135][136][137][138][139][140][141][142][143][144] (aerobic) oxidation, [144][145][146][147][148][149] and hydrogenation of biomass derivatives [144,[150][151][152][153] ). [126] Another intensified reactor configuration for multiphase (gasliquid or liquid-liquid) catalytic biomass transformation is the spinning disc reactor, consisting of a rotating disc around which fluids are fed.…”

“…With this, 60 % HMF yield at 91 % fructose conversion could be obtained from the homogeneous acid (0.25 M HCl) catalyzed dehydration of 30 wt% fructose after 2.5-3 min at 180°C in a biphasic aqueous-organic (2 : 3 volume ratio) batch system. [135][136][137][138][139][140][141][142]216] A glass chip-based microreactor was used for the biphasic synthesis of HMF by dehydration of fructose using a mixture of MIBK and 2-butanol as the organic solvent (70/30 wt%) and HCl as the catalyst in the aqueous phase (Table 4, entry 2). [215] By operating such a biphasic system in a microreactor under slug flow operation (Figures 2D, 3B and 5), the superior mixing for an efficient reaction in the aqueous phase is ensured and the extraction rate of HMF towards the non-reactive organic phase is accelerated by the enhanced mass transfer inside droplets/slugs and across the interface (due to internal circulation and high interfacial area available), thus reducing the occurrence of side reactions and increasing the yield and selectivity towards HMF.…”

High‐Yield 5‐Hydroxymethylfurfural Synthesis from Crude Sugar Beet Juice in a Biphasic Microreactor

“…This approach showed that unexpectedly high HMF yields and good yields of coproduced GLC can be achieved from thick juice. Subsequently, the use of a biphasic continuous microreactor operated in the slug‐flow regime was shown to be extremely beneficial for further improving HMF selectivity (Figure ) . The results were compared with those obtained for pure SUC, clearly showing the beneficial effect of the use of crude thick juice for HMF and GLC production.…”

Continuous Production of 5‐Hydroxymethylfurfural from Monosaccharide over Zirconium Phosphates

“…synthesized HMF from fructose in both batch and continuous flow conditions by employing i ‐PrOH/DMSO as solvent system in the presence of Amberlyst‐15 . And HMF was effectively produced from fructose and glucose using phosphate buffer saline (reaction phase)/2‐ sec ‐butyl phenol (extraction phase) biphasic reaction system in a microreactor by Muranaka and co‐workers . Moreover, acidic metal phosphates were shown to be effective for conversion of monosaccharides into HMF, due to its acidity, structure superiorities with large surface areas and large pores, high thermal stability, allowing its possible recovery and reuse in recent years .…”

“…[9] And HMF was effectively produced from fructose and glucose using phosphate buffer saline (reaction phase)/2-sec-butyl phenol (extraction phase) biphasic reaction system in a microreactor by Muranaka and co-workers. [10] Moreover, acidic metal phosphates were shown to be effective for conversion of monosaccharides into HMF, due to its acidity, structure superiorities with large surface areas and large pores, high thermal stability, allowing its possible recovery and reuse in recent years. [11] For example, Parshetti et al have reported the excellent performances of metal phosphate with weak Brönsted/Lewis acidic sites for production of HMF from food waste.…”