Depolymerization of Pine Wood Organosolv Lignin in Ethanol Medium over NiCu/SiO and NiCuMo/SiO Catalysts: Impact of Temperature and Catalyst Composition.

The process of thermocatalytic conversion of pine ethanol lignin in supercritical ethanol was studied over NiCu/SiO and NiCuMo/SiO catalysts bearing 8.8 and 11.7 wt.

Reductive Fractionation of Flax Shives in Ethanol Medium over RuNi Bimetallic Catalysts.

The reductive catalytic fractionation of flax shives in the presence of bimetallic NiRu catalysts supported on oxidized carbon materials (CM) such as mesoporous Sibunit and carbon mesostructured by KAIST (CMK-3) was studied. The catalysts based on CMK-3 were characterized by a higher surface area (1216 m/g) compared to the ones based on Sibunit (315 m/g). The catalyst supported on CMK-3 (10Ni3RuC400) was characterized by a more uniform distribution of Ni particles, in contrast to the Sibunit-based catalyst (10Ni3RuS450), on the surface of which large agglomerated particles (300-400 nm) were presented.

Fractionation of Aspen Wood to Produce Microcrystalline, Microfibrillated and Nanofibrillated Celluloses, Xylan and Ethanollignin.

A new method for extractive-catalytic fractionation of aspen wood to produce microcrystalline (MCC), microfibrillated (MFC), nanofibrilllated (NFC) celluloses, xylan, and ethanollignin is suggested in order to utilize all of the main components of wood biomass. Xylan is obtained with a yield of 10.2 wt.

Preparation and Characterization of di- and Tricarboxylic Acids-Modified Arabinogalactan Plasticized Composite Films.

To ensure the high quality of water, it is necessary to remove toxic pollutants. At present, purification of water is implemented using various sorbents. The efficient sorption materials are modified polysaccharides.

New Azo Derivatives of Ethanol Lignin: Synthesis, Structure, and Photosensitive Properties.

Water-soluble azo derivatives of lignin were synthesized by the azo coupling reaction using organosolv ethanol lignin and diazonium salts based on sulfanilic acid and p-nitroaniline. The structure of azo derivatives of lignin were studied by nuclear magnetic resonance, Fourier-transform infrared spectroscopy, and gel permeation chromatography. It was found that the azobenzene bonds formed in the azo coupling reaction of macromolecules impart the photosensitive properties to the synthesized polymers via cis-trans photoisomerization of the diazobenzene group.

Larix Sibirica Arabinogalactan Hydrolysis over Zr-SBA-15; Depolymerization Insight.

Arabinogalactan depolymerization over solid Zr-containing SBA-15-based catalyst was studied via HPLC, GPC, and theoretical modeling. Arabinogalactans (AG) are hemicelluloses mainly present in larch wood species, which can be extracted on an industrial scale. The application of solid acid catalysts in the processes of hemicellulose conversion can exclude serious drawbacks such as equipment corrosion, etc.

Acceleration by Double Activation Catalysis and its Negation with Rising Temperature in Hydrolysis of Cellobiose with Phthalic and Hydrochloric Acids.

Double activation catalysis was experimentally observed in hydrolysis of cellobiose catalyzed simultaneously with phthalic and hydrochloric acids, confirming earlier theoretical prediction known from literature. Both acids can catalyze the reaction individually, and contribution of the double-activation pathway to the total reaction rate declines as temperature increases. In fact, above a certain temperature, the hydrolysis rate in presence of both acids becomes lower than the sum of the rates for the two acids acting individually.

One-pot synthesis of sorbitol via hydrolysis-hydrogenation of cellulose in the presence of Ru-containing composites.

The aim of this work was to study the one-pot synthesis of sorbitol via hydrolysis-hydrogenation of cellulose in the presence of Ru-containing composites based on HPWO supported on ZrO and NbO (Ru-PW/ZrO and Ru-PW/NbO). The main parameters impacted the reaction rate and yield of sorbitol, i.e.

One-pot synthesis of formic acid hydrolysis-oxidation of potato starch in the presence of cesium salts of heteropoly acid catalysts.

Solid bifunctional catalysts based on cesium salts of V-containing heteropoly acids (CsHPA: CsHPWVO, CsHSiWVO, CsHPMoVO) and CsHPMoO were used for studying one-pot hydrolysis-oxidation of potato starch to formic acid at 413-443 K and 2 MPa air mixture. It was shown that the optimum process temperature that prevents formic acid from destruction is 423 K. The studies were focused on the influence of the composition of heteropoly anions on the yield and selectivity of formic acid.

Unidimensional Approximation of the Diffuse Electrical Layer in the Inner Volume of Solid Electrolyte Grains in the Absence of Background Ions.

In this paper we continue working on our theory of electrical double layers resulting exclusively from dissociation of a solid electrolyte, which we previously proposed as a medium for catalytic interaction between solid cellulose and solid acid catalysts of hydrolysis. Two theoretical unidimensional models of the inner grain volume are considered: an infinitely long cylindrical pore, and a gel electrolyte near a grain outer surface. Despite the model simplicity, the predictions for the cylindrical pore case are in semi-quantitative agreement with literature data on electroosmotic experiments, adequately explaining high proton selectivity of sulfonic membranes, and decline of such selectivity at high background acid concentration.

Spontaneous Resolution and Super-coiling in Xerogels of the Products of Photo-Induced Formose Reaction.

This work addresses the supramolecular self-organization in the xerogels of formose reaction products. The UV-induced formose reaction was held in over-saturated formaldehyde solutions at 70C without a catalyst. The solutions of the obtained carbohydrates were dried on a glass slide, and the obtained xerogels demonstrated a prominent optical activity, while the initial solutions were optically inactive.

Electrical Double Layer as a Model of Interaction between Cellulose and Solid Acid Catalysts of Hydrolysis.

Solid acid catalysts of cellulose hydrolysis in aqueous media attract considerable research interest because of the ease of their separation from the reaction products. The nature of interaction between the two solids is a relevant topic of ongoing research. One aspect of behavior of solid acids in water was not previously discussed in literature with regard to hydrolysis of cellulose: electrolytic dissociation and formation of electric double layers.

Colloidal Fe , Mn , Co , and Cu Hydroxides Stabilized by Starch as Catalysts of Water Oxidation Reaction with One Electron Oxidant Ru(bpy).

Colloidal catalysts for oxidation of water to dioxygen, which are stable on storage and under the reaction conditions, are synthesized based on Co , Mn , Fe and Cu hydroxides. Stabilization of the colloids with dextrated starch allows the process of hydroxide ageing to be stopped at the stage of the formation of primary nuclei (ca. 2-3 nm from transmission electron microscopy data).

Bioprospecting thermophilic glycosyl hydrolases, from hot springs of Himachal Pradesh, for biomass valorization.

The harnessing of biocatalysts from extreme environment hot spring niche for biomass conversion is significant and promising owing to the special characteristics of extremozymes attributed by intriguing biogeochemistry and extreme conditions of these environments. Hence, in the present study 38 bacterial isolates obtained from hot springs of Manikaran (~ 95 °C), Kalath (~ 50 °C) and Vasist (~ 65 °C) of Himachal Pradesh were screened for glycosyl hydrolases by in situ enrichment technique using lignocellulosic biomass (LCB). Based on their hydrolytic potential 5 isolates were selected and they were Bacillus tequilensis (VCB1, VCB2 and VSDB4), and B.

Delignification of corncob via combined hydrodynamic cavitation and enzymatic pretreatment: process optimization by response surface methodology.

Background: Renewable liquid biofuel production will reduce crude oil import of India. To displace the huge quantity of fossil fuels used for energy production, this research was focused on utilization of unexploited low-cost agricultural residues for biofuel production. Corncobs are a byproduct of corn processing industry, and till now it is not utilized for biofuel production, eventhough it has high lignocellulosic concent.

Cellulose Biorefinery Based on a Combined Catalytic and Biotechnological Approach for Production of 5-HMF and Ethanol.

In this study, a combination of catalytic and biotechnological processes was proposed for the first time for application in a cellulose biorefinery for the production of 5-hydroxymethylfurfural (5-HMF) and bioethanol. Hydrolytic dehydration of the mechanically activated microcrystalline cellulose over a carbon-based mesoporous Sibunt-4 catalyst resulted in moderate yields of glucose and 5-HMF (21.1-25.

Catalytic formation of monosaccharides: from the formose reaction towards selective synthesis.

The formose reaction (FR) has been long the focus of intensive investigations as a simple method for synthesis of complex biologically important monosaccharides and other sugar-like molecules from the simplest organic substrate-formaldehyde. The fundamental importance of the FR is predominantly connected with the ascertainment of plausible scenarios of chemical evolution which could have occurred on the prebiotic Earth to produce the very first molecules of carbohydrates, amino- and nucleic acids, as well as other vitally important substances. The practical importance of studies on the FR is the elaboration of catalytic methods for the synthesis of rare and non-natural monosaccharides and polyols.