Production of Levulinic Acid via Cellulose Conversion Over Metal Oxide-Loaded MOF Catalysts in Aqueous Medium

Mini-Review on the Synthesis of Furfural and Levulinic Acid from Lignocellulosic Biomass

Efficient conversion of renewable biomass into value-added chemicals and biofuels is regarded as an alternative route to reduce our high dependence on fossil resources and the associated environmental issues. In this context, biomass-based furfural and levulinic acid (LA) platform chemicals are frequently utilized to synthesize various valuable chemicals and biofuels. In this review, the reaction mechanism and catalytic system developed for the generation of furfural and levulinic acid are summarized and compared. Special efforts are focused on the different catalytic systems for the synthesis of furfural and levulinic acid. The corresponding challenges and outlooks are also observed.

Conversion of Glucose to 5-Hydroxymethylfurfural, Levulinic Acid, and Formic Acid in 1,3-Dibutyl-2-(2-butoxyphenyl)-4,5-diphenylimidazolium Iodide-Based Ionic Liquid

The separation process between 5-hydroxymethylfurfural (HMF) and trace glucose in glucose conversion is important in the biphasic system (aqueous–organic phase), due to the partial solubility property of HMF in water. In addition, the yield of HMF via the dehydration reaction of glucose in water is low (under 50%) with the use of Brønsted acid as a catalyst. Therefore, this study was conducted to optimize the production and separation of products by using a new hydrophobic ionic liquid (IL), which is more selective than water. The new IL (1,3-dibutyl-2-(2-butoxyphenyl)-4,5-diphenyl imidazolium iodide) [DBDIm]I was used as a solvent and was optimized for the dehydration reaction of glucose to make a more selective separation of HMF, levulinic acid (LA), and formic acid (FA). [DBDIm]I showed high performance as a solvent for glucose conversion at 100 °C for 120 min, with a yield of 82.2% HMF, 14.9% LA, and 2.9% FA in the presence of sulfuric acid as the Brønsted acid catalyst.

The performance of 1,3-dipropyl-2-(2-propoxyphenyl)-4,5-diphenylimidazolium iodide based ionic liquid for biomass conversion into levulinic acid and formic acid

Ionic liquid (IL) demonstrates better performance as a solvent in the biomass conversion process than conventional organic solvents. This study focuses on the application of new hydrophobic imidazolium-based IL as a solvent in biomass conversion process. A novel IL, namely, 1,3-dipropyl-2-(2-propoxyphenyl)-4,5-diphenylimidazolium iodide ([DPDIm]I), was synthesized and subsequently used as a solvent for biomass conversion to produce levulinic acid (LA) and Formic Acid (FA). The performance of [DPDIm]I supported by H₂SO₄ as a solvent was shown by cellulose conversion into 94.23% of LA and 18.85% of FA at the optimum conditions of 140 °C temperature and the reaction time of two hours. A reusability test revealed the performance of [DPDIm]I as a solvent that can be recycled up to five timesfor biomass conversion.