Glucose conversion into hydroxymethylfurfural via ionic liquid-based processes

The majority of lignocellulosic biomass is composed of plant cell walls, which serves as a sustainable source of biomaterials and biofuel. Carbohydrates like glucose and fructose make up the vast bulk of biomass. Every major intermediate molecule formed during glucose conversion has a great degree of flexibility, 5-hydroxymethylfurfural (HMF). However, due to the ease with which LA and HMF degrade into by-products, their yield remains modest. As a result, ionic liquid (IL) is utilized as a solvent to avoid HMF degradation. Furthermore, IL is recyclable, has a high capacity for biomass decomposition, and has the potential to act as a catalyst. Many important aspects of glucose conversion into HMF utilizing IL as a solvent should be explored, including conversion yield, which is affected by the IL utilized, conversion temperature, conversion time, and co-solvent employed. The conversion of glucose to HMF has problems such as low yield and difficult product separation. Without a catalyst, the yield is only around 0–40% wt, and this result was obtained after 3–24 h of reaction time and at around 180 °C reaction temperature. Based on a thorough analysis of the literature, it appears that the ideal temperature range for glucose conversion is 110–120 °C, with a reaction time of 1–2 min utilizing microwave irradiation, and the best type of ionic liquid used is BMIM-based cation. The detailed summary of the optimization of glucose conversion to HMF using IL is deeply discussed in this review paper.