Microwave-assisted HMF production from water-soluble sugars using betaine-based natural deep eutectic solvents (NADES)

Abstract

The combination of a new NADES system and MW irradiation allowed for the preparation of HMF in high yields and in short reaction times.

Furfural and 5‐Hydroxymethylfurfural Production from Sugar Mixture Using Deep Eutectic Solvent/MIBK System

“…As a result, the HMF yield in the organic phase was better than using just MIBK by 5 %, leading to a 50 % yield (Table 1, entry 8). This is consistent with the HMF extraction test by Gomes et al., which revealed that EtOAc was 6 % better at extracting solvent than MIBK [26] . When using ethyl acetate, 29 % of HMF was not detected either from the organic phase or from DES, which is an approximately similar order of magnitude to the missing 21 % in the MIBK reaction.…”

“…Additionally, in a study presented by Morais et al., 1 : 3 ChCl/GA DES (with 5 wt.% H 2 O) was more effective than 1 : 2 ChCl/GA DES (with 5 wt.% H 2 O) for producing furfural from xylan [18] . Reaction temperatures were 150, 160, and 170 °C, and reaction times reported in the literature ranged from 2.5 to 25 mins [18,26] . A small quantity of water (0.5 equiv., 2.5 wt.%) was used as part of the DESs because it has been suggested that a small quantity of water weakens the hydrogen bonds between HBD and HBA, making them more available and reactive [27] .…”

“…This is consistent with the HMF extraction test by Gomes et al, which revealed that EtOAc was 6 % better at extracting solvent than MIBK. [26] When using ethyl acetate, 29 % of HMF was not detected either from the organic phase or from DES, which is an approximately similar order of magnitude to the missing 21 % in the MIBK reaction. Since the ethyl acetate increased the HMF yield only slightly and the furfural extraction to EtOAc was worse than to MIBK, lowering the yield from 98 to 91 % (Table 1, entry 9), MIBK was kept as an extracting solvent.…”

“…[18] Reaction temperatures were 150, 160, and 170 °C, and reaction times reported in the literature ranged from 2.5 to 25 mins. [18,26] A small quantity of water (0.5 equiv., 2.5 wt.%) was used as part of the DESs because it has been suggested that a small quantity of water weakens the hydrogen bonds between HBD and HBA, making them more available and reactive. [27] Kinetic profiles of HMF and furfural formation are displayed in Figure 2 and based on them, it appears that temperature has quite a limiting effect on HMF and furfural yields.…”

Microwave-assisted hydrothermal treatments for biomass valorisation: a critical review

“…158 Thus, greener and more energy-efficient methodologies should be developed. [170][171][172][173][174] Besides, levulinic acid (LA) is another important green platform chemical produced using biomass as a feedstock. LA derivatives are more environmentally friendly alternatives to the fossil fuel resources currently used in organic and polymer synthesis and the fuel industry.…”