Adsorption Of Fructose Research Articles

Structural features of cotton gin trash derived carbon material as a catalyst for the dehydration of fructose to 5-hydroxymethylfurfural

Biomass-derived carbon catalysts have been extensively studied for the dehydration of sugars to platform chemical 5-hydroxymethyl furfural (HMF), which can be used to produce valuable chemicals and fuels. However, only limited studies have been conducted to determine their carbon molecular structures and how these influence the conversion process. Here, we prepare a chlorosulfonated carbon catalyst derived from cotton gin trash (CGT) at 400 °C for the dehydration of fructose to produce 5-hydroxymethyl furfural (HMF) in the ionic liquid, 1-butyl-3-methyl-imidazolium chloride ([BMIM]Cl). The highly efficient chlorosulfonated carbon catalyst consisting of 3 aromatic layers of furanic, phenolic rings and aliphatic–aromatic carbon structures with –COOH, phenolic OH, -SO3-, and -SO3H functional groups were found to have a similar performance as the commercial catalyst, Amberlyst-15. The carbon material was reused 5 times without loss of catalytic activity. The formation of the sugar intermediate, 3,4-dihydroxy-5-hydroxymethyl-tetrahydrofuran-2-carbaldehyde may be related to –COOH and phenolic OH groups forming hydrogen bonds with fructose, and the adsorption of fructose onto the graphitized sp2 internal carbon regions where interactions with the defects in the carbon material occur.

Synthesis of 5-hydroxymethylfurfural from highly concentrated aqueous fructose solutions using activated carbon

An efficient and environmentally friendly system for producing 5-hydroxymethylfurfural (5-HMF) from fructose has been proposed. Substrate concentration is an important factor for practical application of the process; however, use of a high concentration of fructose has rarely been tested in the reaction because the conditions accelerate intermolecular side reactions to form adhesive humins. Humin byproducts stuck on reactor surfaces can make the production of 5-HMF on an industrial scale difficult. Therefore, developing a catalytic reaction system that can promote the synthesis of 5-HMF from highly concentrated fructose without causing adhesion of humins to reactors is needed. The present study demonstrated that activated carbons are promising materials for this system. Activated carbon catalyzed the conversion of fructose to 5-HMF without adhesion of humins to reactor vessels under practical conditions of high substrate concentration up to 73.2%. The catalytic activity was determined not only by the amount of surface weakly acidic oxygenated groups but also by the adsorption of fructose. In addition, strong adsorption of 5-HMF led to low selectivity of 5-HMF and the formation of adhesive humins. This is the first report to describe the synthesis of 5-HMF from solutions containing a fructose concentration greater than 70%.

Controllable and scalable synthesis of hollow-structured porous aromatic polymer for selective adsorption and separation of HMF from reaction mixture of fructose dehydration

The hollow-structured porous aromatic polymers (H-PAP) with cavity diameter from 228 ± 11 to 464 ± 15 nm were controllably prepared through surface coating and template-etching method under scalable synthesis conditions from standard scale to 20-fold scale-up. It is found that the fill factor (f) of reactor is an important parameter for determining the scalability of synthesis. Benefiting from the favorable textural properties, chemical and thermal stability, surface hydrophobicity and π electrons, the well-developed H-PAP as adsorbent was investigated in selective adsorption of 5-hydroxymethylfurfural (HMF) under static batch mode from the single-component and multi-component aqueous solutions. The H-PAP shows an exclusive adsorption for HMF, without adsorption of fructose, levulinic acid (LA) and formic acid (FA), and can be recycled three times without significant decrease in adsorption capacity. Structure-performance relationship points out that the apparent amount of HMF adsorbed on H-PAP is related to micropore surface area, micropore volume and cavity diameter, while HMF selectivity depends on surface hydrophobicity. In the case of HMF adsorption from the real reaction mixture of acid-catalyzed fructose dehydration, the HMF constituent with high purity (ca.94.4%) can be recovered. Combining the adsorption isotherms with DFT calculation reveals adsorption mechanism that HMF adsorption on H-PAP proceeds initially via π–π stacking interaction, and then assembles into regular array around spherical surface to form monolayer coverage following modified Langmuir model, and finally diffuses into interior cavity until adsorption saturation.

Adsorption of fructose in Sn-BEA zeolite from periodic density functional calculations

Sn-BEA zeolite selects fructose conformers from biochemically relevant polysaccharides rather than gas phase, and dispersion effects contribute significantly during interactions.

Dynamic simulation of the integrated bioreactor

The article reports numerical simulation for the system combining selective adsorption of fructose and an enzyme reaction to produce higher fructose syrup. A procedure for the dynamic simulation of the process in the frame of equations for mass transfer in fixed bed, is obtained by making a solute material balance. A fixed bed model incorporating axial dispersion and a linear driving force for mass transfer was successfully used to estimate optimum operating conditions (switch times and fluid flow rates)

Carbohydrate separation by X‐zeolites. Cation and solvent effects

AbstractThe adsorption of fructose and glucose on X‐zeolites has been studied. The adsorption capacity and the selectivity of adsorption depend on the type of cation in the zeolite, the extent of cation exchange and the solvent used. Fructose and glucose can be conveniently separated by column chromatography using NaCaX as the stationary phase and eluting with aqueous methanol. This system also allows separation of other monosaccharides, of monosaccharides and disaccharides, and of monosaccharides and related alditols.