New methods for the synthesis of organic and carbon composites based on chitosan and aerogel from birch pulp are proposed. The obtained chitosan-cellulose composites have a spongy structure (the size of the cavities is from 50 to 70 microns), a low density (0.041-0.046 g/cm(3)) and a poorly developed meso-macroporous structure. The effect of additives of modifying agents (tannins of larch bark and Cu(Ac) on the porous structure and thermochemical properties of biocomposites has been established. The introduction of tannins reduces the average pore size and increases the specific surface area of the biocomposite. Carbon composites were obtained by carbonation of chitosan-cellulose biocomposites at a temperature of 600 degrees C. The resulting carbon composites have a poorly developed porous structure, and the addition of tannins increases the specific surface area of carbon composites from 1 m(2)/g to 7 m(2)/g and helps reduce the size of mesopores to 10.7-12.4 nm. The porous structure of carbon composites was developed by their thermal alkaline activation with NaOH at 800 degrees C. The surface of carbon composites increases by 2-3 orders of magnitude after activation and reaches 1160 m(2)/g for a sample containing an additive of tannins. The sample doped with copper acetate has the lower specific surface area (588 m(2)/g). Activated carbon composites are micro-mesoporous materials. The ratio of micropores and mesopores in them varies depending on the chemical composition of the initial biocomposite. The properties of the obtained carbon composites based on chitosan and cellulose, such as high specific surface area, adjustable porous structure, low density, and the possibility of chemical modification, open up prospects for their use as catalysts, catalyst carriers, adsorbents.

The paper describes an improved single-stage method for obtaining betulonic acid from birch bark with recrystallization from ethanol. The structure and composition of the obtained betulonic acid were confirmed by FTIR, NMR spectroscopy and elemental analysis. Thermal studies of betulonic acid were carried out using differential scanning calorimeter (DSC). The antitumor activity of betulonic acid and betulin was studied on Ehrlich ascites carcinoma culture in vivo experiments. It was found that under the influence of betulin and betulonic acid the content of dead cells of Ehrlich ascites carcinoma increased. It was shown that betulonic acid has a protective effect on the hematopoiesis system and does not have a toxic effect on the body.

Guaiacol is a lignin model compound often used to study of the lignin and bio-oil hydrodeoxygenation (HDO) pathways, as well as to determine the efficiency of the catalysts used. In the present work, the guaiacol HDO process was studied in the presence of nickel, ruthenium and bimetallic Ni/Ru catalysts prepared on the basis of the pre-oxidized carbon support "Sibunit". The hydrodeoxygenation process was carried out at temperatures of 200-250 degrees C, an initial H-2 pressure of 1.5 MPa in a medium of water, ethanol and dodecane. The bimetallic catalyst containing 10 wt.% Ni and 3 wt.% Ru (3Ru10Ni/C) turned out to be the most active and selective in the conversion of guaiacol into aromatic compounds and cyclic derivatives of alkanes in an aqueous medium. A catalytic study of the guaiacol HDO process in the presence of this bimetallic catalyst was carried out. The influence of the catalyst nature and characteristics on the HDO process routes is discussed.

Sulfation of arabinogalactan (AG) from larch wood (Larix sibirica Ledeb.) in the melt of a sulfamic acid-urea mixture has been first examined. The impact of the AG sulfation temperature on the AG sulfate yield and the sulfur content has been established. The high sulfur content (11.3-11.6%) in sulfated AG has been obtained in the temperature range of 115-120 °C for a sulfation time of 0.5 h. The process effectively prevents molecular degradation under these conditions. The incorporation of sulfate groups into the arabinogalactan structure has been confirmed by the appearance of absorption bands in the FTIR spectrum that are typical of sulfate group vibrations. The 13C NMR spectroscopy study has proven that the AG sulfation in the melt of a sulfamic acid-urea mixture leads to the substitution of some free hydroxyl groups for C6, C4, and C2 carbon atoms of the AG β-D-galactopyranose units. The advantage of the proposed AG sulfation method is that the reaction occurs without solvent, and the reaction time is only 0.5 h. The kinetics of the thermal decomposition of the initial AG and sulfated AG samples have been studied. It has been found that the sulfated AG samples have a lower thermal resistance than the initial AG. The kinetic analysis has revealed a decrease in the activation energy of the thermal degradation of the sulfated samples as compared to the initial AG.

The structure of sodium salts of arabinogalactan (AG) sulfates, obtained by sulfation of AG with sulfamic acid-urea mixture in the homogeneous medium of dimethyl sulfoxide (DMSO) was studied for the first time. According to thermal analysis (TA) data, the onset temperature of thermal decomposition of sulfated AG is 218 degrees C, and that of the initial AG is 235 degrees C. The quantitative characteristics of the kinetics of the main stage of sample pyrolysis were determined using the Coates-Redfern method. It was found that the activation energy of AG is 150 kJ/mol, whereas with the introduction of sulfate groups the activation energy decreases to 35 kJ/mol. The XRD method shows that the amorphization of arabinogalactan structure occurs during it`s sulfation. With the use of SEM method, it was found that the morphology of the obtained arabinogalactan sulfates differs from the morphology of the initial arabinogalactan. The initial AG consists mainly of globular particles with size of 10-90 mu m, while sulfated AG-of spherical particles with a diameter of 1-10 mu m. According to AFM data, the surface of film of arabinogalactan sulfates is formed by the rather homogeneous spherical particles with an average diameter of 50 nm and does not contain any impurities in its phase composition.

A new method for fractionating pine bark to obtain anthocyanidins and powdered cellulose was proposed. Anthocyanidins were isolated from pine bark by treatment with a solution of hydrochloric acid in ethanol with a yield of 10.1 wt.%. The presence of cyanidin and delphinidin in the composition of anthocyanidins was confirmed by UV spectroscopy method. Experimental and mathematical optimization of the process of peroxide catalytic delignification of pine bark after anthocyanidin extraction was carried out. Delignification process was carried out in the presence of MnSO4 catalyst at a hydromodulus of 20, a temperature of 100 °C and a duration of 4 hours. Using the method of mathematical optimization of the delignification process, optimal conditions for obtaining powdered cellulose from pine bark were established: the concentration of H2O2 6.4 wt.% and CH3COOH 57.1 wt.%. The experimental yield of cellulose product under optimal conditions was 34.1 wt.%, and the content of lignin in it was 1.1 wt.%, cellulose 86.4 wt.%. The crystallinity index of cellulose product was 0.81, the average particle size was 2.74 μm. The characteristics of powdered cellulose were determined by elemental and chemical analysis, FTIR, XRD, SEM, EDS and laser diffraction methods.

In the production of powdered cellulose by peroxide delignification of pretreated pine bark in the medium << acetic acid-water-catalyst MnSO4 >> the soluble by-products are formed with an yield of 27 % from mass of bark. They are presented by soluble acetic acid lignin, hemicelluloses and low-molecular weight organic compounds. The content of acetic acid lignin was 16.3 % from the total weight of soluble products, hemicelluloses-5.9 %, water-soluble low-molecular products-21.8 %, ethyl acetate-soluble products-55.9 %. The structure and composition of lignin were established by FTIR,P- 31 NMR, SEM, EDS, and laser diffraction methods, and that of hemicelluloses-by FTIR and GC methods. The acetic acid lignin is characterized by a high content of hydroxyl groups. The average particle size of lignin was 2.17 mu m. The following monosaccharides were found in the hemicelluloses composition: glucose-47.4 rel. %, mannose-31.1 rel. %, galactose-11.8 rel. %, xylose-9.6 rel. %. The low molecular weight soluble products of pine bark delignification were divided into ethyl acetate and aqueous fractions and analyzed by FTIR, GC and GC-MS methods. Malonic (16.49 rel. %) and glycolic (14.93 rel. %) acids predominated in the ethyl acetate fraction of soluble products. The hydrolysate of aqueous fraction contains glucose-40.8 rel. %, mannose-27.3 rel. %, xylose-18.8 rel. %.

The purpose of this work was to develop a new one-step method for the synthesis of allobetulin 3-O-formate from birch bark, select optimal synthesis conditions and to studing its influence on blood/plasma coagulation. A new one-step method has been proposed for the synthesis of allobetulin 3-O-formate from birch bark Betula Pendula Roth., based on combining the extraction of betulin, its isomerization into allobetulin in the presence of a catalyst - orthophosphoric acid, and the esterification of allobetulin with formic acid. The influence of the duration of the process of treating birch bark with formic acid and the H3PO4 content on the yield of allobetulin 3-O-formate was established. The highest yield of crude allobetulin 3-O-formate (37% by weight of a.d.b.) is achieved at a process duration of 12 hours in the presence of 10% H3PO4, as well as with a duration of 16 hours in the presence of 8% H3PO4. The yield of recrystallized from ethanol allobetulin 3-O-formate is about 30% by weight of the a.d.b. The composition of the obtained samples of recrystallized allobetulin 3-O-formate was determined by elemental analysis, and its structure was confirmed by IR and NMR spectroscopy. In vitro experiments conducted using human donor blood showed that allobetulin 3-O-formate exhibits pronounced procoagulant properties and does not have a significant effect on the erythrocyte membrane. Allobetulin 3-O-formate can be used to create biomaterials with specified properties in relation to blood coagulation.

The effect of the catalyst V/zeolite KN-30 on the formic acid yield in the process of oxidative hydrolysis of dissolved hemicellulose oligosaccharides obtained by hydrothermal treatment of aspen wood at 180 degrees C was established. The catalyst obtained by impregnation of ZSM-type zeolite KN-30 with NaVO3 was characterized using the methods of SEM, XRD, BET and temperature- programmed desorption of ammonia. Under optimal conditions of the process of oxidative hydrolysis of hemicellulose catalytic process 1.5 mas.%). The catalyst activity in the process of oxidative hydrolysis of oligosaccharides hours of operation.

This paper examines the composition and structure of hydrochars obtained by hydrothermal carbonization (HTC) of aspen wood, as well as porous carbon materials formed during their thermochemical activation at 800 degrees C using KOH, Fe(NO3)(3), and K-3[Fe(CN)(6)]. It was established by chemical and elemental analysis, IR spectroscopy, X-ray diffraction, and scanning electron microscopy methods that increasing the hydrothermal carbonization temperature from 180 degrees C to 240 degrees C leads to the destruction of wood hemicelluloses and cellulose. Hydrochars obtained at temperatures 230 degrees C and 240 degrees C consist of so-called "pseudolignin." Carbon-containing microspheres are formed on the surface of the hydrochars, the number of which increases with HTC temperature. As the hydrochar production temperature increases, their thermal stability is becoming higher. Thermochemical activation of hydrochars at 800 degrees C using KOH, Fe(NO3)(3), and K-3[Fe(CN)(6)] significantly develops the porous structure of the carbon product. The specific surface area of the carbon samples increases in the following order of activators: Fe(NO3)(3) (up to 310 m(2)/g) < K-3[Fe(CN)(6)] (up to 586 m2/g) < KOH (up to 1381 m2/g). Metallic iron compounds and iron carbides Fe3C are uniformly distributed on the surface of the sample activated with Fe(NO3)(3), while iron oxides and iron carbides Fe3C and FeC are present on the surface of the sample activated with K-3[Fe(CN)(6)]. Pseudolignin microspheres forming on the surface of the hydrochars remain on the surface of the activated carbon materials as carbon microspheres. With sizes 1-8 mu m ron-containing samples have magnetic hysteresis and the saturation magnetization value allows them to be isolated from a liquid medium using a magnet.

Transition metal catalysts supported on carriers stable in hydrothermal conditions are increasingly used for processing woody biomass and its components into valuable chemical and liquid fuels. The review summarizes the publications recent years in the field of the use of Zr/Hf- containing materials as catalysts and co- catalysts, catalyst carriers in the processes of transformation of biomass and plant substrates. Promising areas of research activity are related to the synthesis of catalysts based on Zr/Hf organic hybrid materials and organometallic frameworks, containing Zr and Hf. In obtaining such materials, researches strive to use simple synthesis methods and available reagents.

The review considers recent advances in the field of heterogeneous metal-containing catalysts for the production of hydrogen as an environmentally benign energy carrier by dehydrogenation of formic acid, which is an accessible and low-toxic substance. Although the activity of homogeneous catalysts in the dehydrogenation of formic acid is higher compared to heterogeneous catalysts, the application of the latter ones makes it possible to simplify the technology and increase the environmental safety of hydrogen production from formic acid. The efficiency of heterogeneous catalysts for dehydrogenation of formic acid based on noble metals (Pd, Au, Ag) can be enhanced by the development of advanced methods for the synthesis of monometallic, bimetallic and trimetallic nanoparticles on different supports. The efficiency of different heterogeneous nanocatalysts in dehydrogenation of formic acid is compared and various factors (the nature of a metal, the size of nanoparticles, their composition, and features of the support) affecting their activity and selectivity to hydrogen are discussed. A considerable increase in the activity toward dehydrogenation of formic acid is achieved by enhancing the interaction of metal nanoparticles with the surface of chemically modified substrate, which decreases the size of nanoparticles, increases the uniformity of their distribution over the substrate and changes the electronic state of the metal. Advances in the development of industrial heterogeneous catalysts for the production of pure hydrogen from formic acid will ensure an essential contribution to the development of hydrogen energetics.

The effectiveness of the methods for extraction purification from the alpha 1-fraction (substances insoluble in quinoline) of coal tar pitch produced by atmospheric distillation of "PAO Koks" coal tar using aromatic solvents obtained by distillation of coal tar and mixed naphtene- aromatic solvents has been compared. For the production of an electrode binder, it is proposed to use the purification of coal tar pitch by gravitational precipitation of the alpha 1-fraction from a mixed solvent (crude benzene and 5 % mas of formic acid) after extraction treatment at 85 degrees C. This method allows to produce purified coal tar with an alpha 1-fraction content no more than 3 % mas. For the production of needle coke and carbon fibers it is suggested to use a two- stage method of coal tar purification, including, in the first stage, gravitational precipitation of an alpha 1-fraction from a mixed solvent (crude benzene and 5 % mas of formic acid) after extraction treatment at 85 degrees C, and at the second stage- additional- purification of pitch by extraction with a mixed solvent (crude benzene and 5 % mas of formic acid) under supercritical conditions at a temperature of 300 degrees C. This method allows to produce purified coal tar with an alpha 1-fraction content of no more than 0.2 % mas. The feasibility of using formic acid for pitch purification is due to the fact that it is a hydrogen- donating solvent and can be easily produced with a low carbon footprint from cheap renewable plant raw materials. The obtained samples of purified coal pitches were characterized by chemical and elemental analysis, gel penetrating chromatography, IR spectroscopy, H 1 NMR spectroscopy.

The influence of the method of thermal- alkaline activation of biochars from larch bark with NaOH on the formation of the porous structure of active carbons was established. A comparison was made of the textural characteristics and sorption properties of the active carbon samples obtained by thermal- alkaline activation of the original and carbonized larch bark. The possibility of regulation of the textural, morphological and sorption properties of active carbons by varying the method of thermal alkaline activation of the bark is shown. The most effective development of the porous structure of active carbons was observed after thermal- alkaline activation (800 degrees C, 20 % NaOH) of larch bark subjected to carbonization at temperatures 400 degrees C and 600 degrees C. The specific surface area of these samples reaches to 546 m2/g and 501 m2/g, respectively. Active carbons obtained by thermal- alkaline activation (800 degrees C, 10 % and 20 % NaOH) of the original bark have less developed specific surface area (260 and 380 m2/g, respectively). Pre- carbonization of the bark also helps to increase more than double the yield of active adsorption capacity in relation to benzene (350 mg/g) is demonstrated by a sample of active carbon obtained by thermal- alkaline activation of bark, pre- carbonized at 400 degrees C, and in terms of methylene blue sorption (94 mg/g) - by a sample obtained from bark pre- carbonized at 600 degrees C.

A novel bifunctional catalyst based on Ni supported on hafnium oxide was prepared to depolymerise birch wood lignin. A native lignin fraction of birch wood was promptly depolymerised into valuable phenolic monomers, enriched with propenylsyringol through one- pot catalytic reductive fractionation at 225 degrees C, and 4 MPa H-2 during 3 hours. The yield of liquid products increased from 23 to 37 wt.% under the hydrogenation in the presence of catalyst. Detailed Brunauer- Emmett- Teller, & rcy;& Ncy; of the point of zero charge, and X-ray photoelectron spectroscopy investigations revealed that the metal-acid synergistic effect in the presence of acid sites and of both Ni(2+)and Ni- 0 were responsible for the breaking of C-C bond, ester and ether linkages bonds in lignin. Moreover, modifying catalyst by phosphoric acid generated propenylsyringol in higher yield. Overall, this report highlighted the potential of the simple preparation strategy of the bifunctional catalyst based on Ni supported on acidic HfO2 to depolymerize wood lignin and proposed possible mechanism for reductive catalytic fractionation of birch wood biomass.

For the first time, polysaccharides: cellulose and xylan, isolated from birch wood by peroxide delignification in "acetic acid- water" medium in the presence of catalyst (NH4)6Mo7O24, were proposed to be used to obtain polymer composites (films). The initial components: cellulose, xylan, sodium alginate were characterized using the methods of FTIR, GC, GPC, laser diffraction and chemical analysis.It is shown that the introduction of ultrasound- activated birch bark cellulose into the composition of xylanalginate composites leads to an increase in the strength of the films, an increase in their barrier properties with respect to water vapor, and also reduces the solubility of the films in water.

In present paper, it is proposed to use tannins ethanol- isolated out of mechanically activated pine bark in synthesis of rigid foams without formaldehyde addition. The results obtained using IR and UV spectroscopy indicate that mechanical activation of the bark leads to a change in the content of hydrolyzed and condensed tannins in pine bark extracts. In particular, the composition of extracts obtained from bark activated by energy- tensed AGO-2 retains the highest content of hydrolyzable and condensed tannins, which amount to 62 and 9.4 mg/g of bark, respectively. Using the GPC method, it was established that obtained pine bark tannins being oligomeric: their molecular weight distribution has a bimodal shape with the peaks in 500 and 1000 g/mol regions. Synthesized by so- condensation via furfuryl alcohol tannin- containing rigid foams (TCRF) possess a cellular- type structure with a smooth surface and partially open cavities up to 10 mu m, as detected using SEM. The bulk density of the TCRF lies in range 0.64-0.82 g/cm3, 3 , and their specific compressive strength is about 11.8-19.9 kg/cm(2). It was revealed that calculated thermal conductivity coefficient of the TCRF, which varies in range of 0.129-0.185 W/(m center dot K), compared to known analogues, is close to aerated concrete with thermal conductivity 0.1-0.3 W/(m center dot K). Thermal stability of the TCRF in an argon atmosphere indicates that in the 30-800 degrees C temperature range samples thermal decomposition proceeds uniformly without a sharp mass loss with a low activation energy (10.6-12.6 kJ/mol). The carbon residues yield of the samples after TGA/DSC performed varies in range 42-49 wt.%.

The characteristics and properties of biodegradable films synthesized on the basis of nanofibrillated pine cellulose and wood hemicelluloses are studied for the first time. Nanofibrillated cellulose (NFC) was obtained by peroxide delignification of pine wood in an acetic acid- water medium, followed by grinding of cellulose in a ball mill and ultrasonic treatment. The average hydrodynamic diameter of the particles of the obtained NFC suspension is 105 nm, the average charge of the suspension particles was -11.4 mV. The films were obtained by mixing the NFC suspension with wood hemicelluloses and fillers (sorbitol, collagen, starch, glycerol). The obtained films were characterized by IR, XRD, SEM, AFM, spectrophotometry, thermal analysis and chemical methods. Such characteristics of the films as moisture absorption, opacity and light transmission were determined. The highest transparency, thermal stability and low water sorption are demonstrated by films obtained from a mixture of NFC, pine hemicelluloses and collagen and starch plasticizers together with glycerin. Composite films are characterized by good barrier properties in the UV range.

Siberian larch wood (Larix sibirica Lebed.) contains such valuable biologically active substances as dihydroquercetin (DHQ) and arabinogalactan (AG), promising for the use in the pharmaceutical and food industries. An urgent task is to improve the methods of extraction isolation of these compounds from wood. In this work, we studied the possibility of simultaneous isolation of dihydroquercetin and arabinogalactan by extraction of larch wood with 5–25% aqueous ethanol solutions. It has been shown that by extracting wood with aqueous solutions with a low concentration of ethanol, it is possible to exclude the stage of separation of resinous substances from the target products of DHQ and AG. By experimentally optimizing of water-ethanol extraction process, it was shown that the highest yields of DHQ (1.8% mas.) and AG (18.0% mas.) were achieved by extraction of larch wood, crushed to particles of 1–3 mm in size, with a 15% ethanol solution for 2 hours. That the preliminarily mechanical treatment of larch wood allows to reduce the time of water-alcohol extraction to 30 minutes and to obtain DHQ and AG with high yields. The structure of DHQ and AG was confirmed by FTIR and NMR spectroscopy. Identification and purity of DHQ isolated from larch wood were confirmed by a photometric method using the reaction of cyanidin chloride formation when DHQ in heated in ethanol in the presence of hydrochloric acid.

This paper presents the latest significant advances in the Ru-containing catalysts application in the reductive processing of lignin and lignocellulosic biomass. The features of the catalytic action of Ru-catalysts in aqueous and water-alcohol media are also considered in comparison with other platinum group metals. The performance of various Ru- based catalytic systems in the processes of lignin depolymerization and processing of lignocellulosic biomass is compared. By modifying and designing supports to provide them acidic properties, a mesoporous structure promoting good reagents transport, and improved distribution of Ru nanoparticles, the efficiency of ruthenium catalysts can be significantly improved. Ru- based catalysts are the most efficient in the processes of reductive processing of lignocellulosic biomass and lignin in aqueous media compared to other platinum group metals.