Optimization Study of Glucose Synthesis to 5-Hydroxymethylfurfural (5-HMF) by Using Low Transition-Temperature Mixtures (LTTM)

Abstract

5-Hydroxymethylfurfural (5-HMF) is a potential value-added product gaining popularity due to its wide range of applications. Glucose is widely used for 5-HMF production because it is abundant and more cost-effective than other resources. In the current research, a combination of microwave irradiation and low transition-temperature mixture (LTTM) for 5-HMF production was sustainably created. A preliminary study was conducted to derive 5-HMF using LTTM as a green solvent in various ratios of glucose: LTTM (MA/ChCl): water (10:100:15) and (10:48:100) via microwave heating at 90 °C for 10–60 min reaction time. The product analysis revealed that the 10:100:15 combination ratio of glucose: LTTM: water produced more 5-HMF (20.5%) than the 10:48:100 (0.28%) ratio. Following the preliminary results, an optimization study was conducted, focusing on the reaction temperature, LTTM mass, and water to assess the impact on 5-HMF yield and glucose conversion, using CCD in Design-Expert software. The quadratic model fit for 5-HMF yield and the 2FI model for glucose conversion yielded R2 values of 0.9861 and 0.8610, respectively. Both responses had a significant p value of 0.0061 for glucose conversion and <0.0001 for 5-HMF yield. An optimum point was achieved at 100 °C, 100 g of LTTM, and 20 g of water, with an expected 5-HMF yield and glucose conversion of 45.77% and 69.03%, respectively.