High purity fructose from inulin with heterogeneous catalysis – from batch to continuous operation

Abstract

BACKGROUND Inulin is a valuable source of high purity fructose. The conversion of inulin to fructose utilizing an advanced sulfonic ion‐exchange resin was previously investigated in detail in a batch reactor study, where a detailed mechanistic model for the reaction kinetics was demonstrated (J Chem Technol Biotechnol 2018;93:224–232). The same catalyst was employed in tailor‐made continuous fixed‐bed reactors in the current work in order to study the feasibility of continuous operation. RESULTS Two types of reactors were utilized: a single‐bed reactor and a multibed reactor with sample withdrawal between catalyst beds. The results from the single‐bed reactor allowed optimal reaction conditions to be determined which were extrapolated and used for experiments in the multiple‐bed reactor. High yields of fructose (75%) were obtained with the multiple‐bed reactor without any degradation products. Detailed flow characterization was performed on the reactor system and residence time distribution results were merged with the detailed model for the chemical kinetics obtained from batch reactor studies taking into account mass transfer limitations, in order to obtain a rigorous model for the performance of the continuous reactor. The fit of the mathematical model to the experimental data was very good and this provides a useful tool for further development and scale‐up purposes. CONCLUSIONS The results of the two related studies highlight the potential of new reactor design strategies towards the realization of more efficient, sustainable and green processes, which can easily be scaled‐up and implemented in bio‐based industry. © 2018 Society of Chemical Industry

Hydrolysis of semi‐industrial aqueous extracted xylan from birch (Betula pendula) employing commercial catalysts: kinetics and modelling

“…24,28 Based on literature and preliminary results obtained at ambient pressure, relatively high temperature and low pH are required in the hydrolysis of xylan compared to inulin, for example. [28][29][30] We selected 115 °C as the operating temperature in the screening as some of the catalysts have a maximum operating temperature of 120 °C. A pH of 0.75 was used to maintain a reasonable solid-liquid ratio.…”

Development of a sustainable route for the production of high‐fructose syrup from the polyfructan inulin

“…High‐fructose syrup (HFS) has increasingly solicited industrial importance over the years as an ingredient in food and pharmaceuticals. As it is 1.2 to 1.6 times sweeter than conventional sucrose, fructose is widely used in the food industry as a sweetener with flavour‐enhancing properties [ 1 ]. It also serves various non‐food applications and has been widely utilized for the production of bulk chemicals.…”

“…Recently, the dehydration of fructose has been extensively explored for the production of the important platform chemical, 5‐hydroxymethylfurfural, which can be utilized for the production of an array of chemical building blocks [ 2 ]. The conventional method for the commercial production of fructose is the isomerization of glucose, mediated by the enzyme isomerase [ 1 ]. However, the enzymatic isomerization of glucose produces an equimolar mixture of the two carbohydrates, which situates an economic constraint in the separation process.…”

Effective hydrolysis of polysaccharides by activated attapulgite

“…studied the hydrolysis of cellobiose catalyzed by activated carbon and found that the weak acid sites were favorable for high selectivity of glucose, while strong acid groups were more accessible for the degradation reactions 12 . Besides carbon catalysts, ion‐exchange resins were also employed for hydrolysis reactions; 75% fructose yield was obtained with the multiple‐bed reactor catalyzed by sulfonic ion‐exchange 13 . Moreover, some metal oxides, such as TiO 2 ‐based catalysts 7 and ZSM‐5 zeolite, 14 were also investigated for polysaccharide hydrolysis.…”