Preparation of 5-Hydroxymethylfurfural from High Fructose Corn Syrup Using Organic Weak Acid in Situ as Catalyst

Abstract

The acidic catalysts play pivotal roles in the dehydration of hexose into 5-hydroxymethylfurfural (HMF). However, these acidic catalysts were usually exogenously added or self-made, which increase the cost of preparation of HMF. Herein, a novel route to prepare HMF from high fructose corn syrup (HFCS-55) using gluconic acid in situ produced by bio-oxidation as a catalyst has been investigated. In the process of bio-oxidation of HFCS-55, the introducing of ε-polylysine (EPL) can effectively improve the acid tolerance of the coimmobilized glucose oxidase and catalase. The immobilized enzymes can keep activity in the existence of a large amount of gluconic acid. Through the chelation of gluconic acid and calcium ions, the degree of gluconic acid ionization was raised and enough protons were released to convert fructose to HMF without the addition of acid. Using 2-methyltetrahydrofuran (2-MeTHF) as an extractor and adding 2 wt % CaCl2, the HMF’s yield reached 85% from fructose–gluconic acid mixture solution at 150 °C for 10 min with 200 W microwave irritations. Furthermore, we also used nuclear magnetic titration to investigate the complexation mechanism of the calcium ion and gluconic acid.

Research advancement in molten salt-mediated thermochemical upcycling of biomass waste

“…, fructose and glucose) in a biphasic system. Lin et al 58 employed a cheap CaCl 2 MSH solvent for performing biomass hydrolysis, achieving 72% fructose conversion and 32% HMF yield in 10% CaCl 2 solution via microwave irradiation. They further studied the isomerization of glucose to fructose, which is followed by the dehydration of fructose in a high-concentration CaCl 2 solution.…”

El maíz y la nixtamalización: modificación de sus componentes, técnicas de proceso y enriquecimiento de tortilla.

“…49 Otra de sus aplicaciones, es para la formación de 5hidroximetilfurfural (HMF) (compuesto principal de plataformas de biomasa), utilizando ácido glucónico como catalizador, capaz de producir suficientes protones para la conversión de fructosa a HMF sin utilizar ácido, este proceso resulta más económico y ecológico que la utilización de fósiles. 50 También se utiliza como fuente de carbono, para producir disolventes a través de la fermentación de acetona-butanol-etanol, funcionando como sustrato de modelo de mezclas concentradas de azúcar mediante la fermentación de monosacáridos y disacáridos, en el cual el producto principal es el butanol, considerado un biocombustible. 51 La nixtamalización consiste en una cocción termo-alcalina del grano de maíz con agua y cal (Ca (OH)2), los granos se muelen para producir masa o se deshidratan para obtener harinas de maíz instantáneas.…”

Structure–activity relationships of LDH catalysts for the glucose-to-fructose isomerisation in ethanol

“…Glucose-to-fructose isomerization is the key process to produce High Fructose Corn Syrup (HFCS), 1 used in industry and also in academia, 2 especially for producing biofuels and platform molecules. 3,4 Moreover, this reaction is also well-known as a crucial step for the catalytic valorisation of the lignocellulose, which is attracting increasing global interest because of the depletion of fossil resources. [5][6][7][8][9][10][11] While industrial catalytic isomerizations have thus far largely utilized the high-performance isomerases as actual catalysts, 1,12 the newly developed catalytic systems are based on inorganic (nano)materials because of the strong limitations of the widely used enzymatic transformations.…”