Experimental and modelling studies on the uncatalysed thermal conversion of inulin to 5-hydroxymethylfurfural and levulinic acid

Abstract

Background: 5-Hydroxymethylfurfural (HMF), an important biobased platform chemical, is accessible by the acid catalysed conversion of biopolymers containing hexoses (cellulose, starch, inulin) and monomeric sugars derived thereof. We here report an experimental study on the uncatalysed, thermal conversion of inulin to HMF in aqueous solutions in a batch set-up. Results:The reactions were conducted in a temperature range of 153-187°C, an inulin loading between 0.03 and 0.12 g/mL and batch times between 18 and 74 min using a central composite experimental design. The highest experimental HMF yield in the process window was 35 wt% (45 mol%), which is 45% of the theoretical maximum (78 wt%). The HMF yields were modeled using a statistical approach and good agreement between experiment data and model was obtained. The possible autocatalytic role of formic acid (FA) and levulinic acid, two main byproducts, was probed by performing reactions in the presence of these acids and it was shown that particularly FA acts as a catalyst. Conclusions:Inulin is an interesting feed for the synthesis of HMF in water. A catalyst is not required, though autocatalytic effects of FA play a major role and also affect reaction rates and product yields. Graphical abstract:Chicory 5-hydroxymethylfurfural No catalystInulin

Experimental and Modeling Studies on the Conversion of Inulin to 5-Hydroxymethylfurfural Using Metal Salts in Water

“…This study complements earlier research in our group on the conversion of inulin to HMF [37]. Inulin is a biopolymer consisting mainly of D-fructose and minor amounts of D-glucose ( Figure 1).…”

Experimental and modeling studies on the acid-catalyzed conversion of inulin to 5-hydroxymethylfurfural in water

“…In a previous study, we have investigated the non-catalyzed, thermal reaction of inulin to HMF (Fachri et al, 2015b). As such it is of interest to compare the performance of a reaction with a catalyst in the form of sulphuric acid with a non-catalyzed reaction.…”

Reaction Mechanism of the Microwave-Assisted Synthesis of 5-Hydroxymethylfurfural from Sucrose in Sugar Beet Molasses

“…The sucrose (Suc) conversion (X Suc ) and products (Glc, Frc, HMF, FA, and Fur) yield (Y P ) were determined by Equations ( 18) and (19), respectively:…”

“…In addition to using MASW technology and an available low-cost carbohydrate-rich source, the study of the kinetic parameters and reaction pathways is required to take any low-scale technology to industrial development. Studies of the kinetics of converting fructose, glucose, and polysaccharides into HMF, using strong homogeneous Brønsted acids and heterogeneous catalysts in water, have already been published [17][18][19][20][21]. However, there is no preceding kinetic study of HMF synthesis from molasses sucrose assisted by MASW technology.…”