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Sulfation of birch wood xylan in 1,4-dioxane by sulfamic acid in the presence of urea at 90 and 100 °C was studied for the first time. The effect of the duration of xylan sulfation on the yield of xylan sulfates and the sulfur content in them was studied. It was found that the sulfur content in the obtained xylan sulfates increases from 12.5 to 17.5 wt% with an increase in the duration of sulfation from 2 to 4 hours. The structure of initial and sulfated xylan was studied by FTIR and NMR spectroscopy. The ease of purification of the obtained xylan sulfates from 1,4-dioxane in comparison with the purification of xylan sulfates obtained by sulfation in pyridine and N, N‑dimethylformamide is an advantage of the proposed method of xylan sulfation

The analysis of the latest publications on the use of hydrolytic lignin, which is a large-tonnage waste of wood chemical processing, was carried out. In its original form, the hydrolytic lignin is used as fuel, fuel briquettes and pellets, binders and adhesives, organic fertilizers, fillers and enterosorbents. The processing of hydrolytic lignin by chemical and thermochemical methods allows to significantly expand the range of valuable products obtained from it. They are used in chemical, oil and gas and construction industries, metallurgy and other areas. Hydrolytic lignin is most widely used for the production of carbon sorbents. Recently, methods of thermochemical processing of lignin into porous carbon materials with the required texture and strength characteristics as well as into valuable organic products have been developed

Pyrolysis of Kaa-Khemsky and Mezhegeisky coals was investigated with an increase in temperature to 900 °С with a change in pressure in the reactor by increasing the retention time of volatile substances in the pyrolysis zone at 600 °С and 640 °С. Liquid products of coal pyrolysis were extracted by hexane and benzene. The composition of liquid extracts was studied by chemical analysis, GC-MS and IR-spectroscopy, the solid product of extraction-by elemental analysis and scanning electron microscopy. It was established, that coal nature and pyrolysis conditions affect significantly on the yield of liquid, solid and gaseous products. Also, the retention time of volatile substances in pyrolysis zone influences on the yield of solid product (increases from 60 %wt to 73 % wt) and on composition of hexane and benzene soluble tar fractions. This is also facilitated by an increase in pressure in the reactor as a result of the release of volatile substances from coal in the pyrolysis zone

It was found that when betulin is sulfated with chlorosulfonic acid in pyridine medium, 3,28-disulfate of betulin is formed in a stable salt form. Under optimal synthesis conditions: temperature 70 °C, duration 2 hours, molar ratio betulin / chlorosulfonic acid 4.0, betulin is completely converted into betulin 3.28-disulfate. The structure and composition of betulin 3,28-disulfate were confirmed by elemental analysis, IR, Raman and 13C NMR spectroscopy. Betulin 3,28-disulfate was isolated both in the form of an unstable H + -form and in a stable forms of sodium and pyridinium salts. Sodium salt of 3,28-disulfate is a needle-like crystals collected in cobweb-like aggregates. The sodium salt of 3,28-disulfate has mycellar properties, the critical concentration of mycellar formation is 0.23 mmol / L.

The regularities of thermocatalytic transformation of pine ethanol lignin in supercritical ethanol in the presence of catalysts NiCu/SiO₂ and NiCuMo/SiO2 in the temperature range 250–400 °C were established. The composition and structure of ethanol lignin, liquid and solid products of its conversion were studied by methods of elemental analysis and gel-permeating chromatography (GPC). The composition of gaseous products – by method of gas chromatography. At the process temperature of 250 °C the catalysts do not have a significant effect on conversion of ethanol lignin. The maximal yield of liquid products (83.5 wt. %) was obtained at temperature 300 °C in the presence of catalyst NiCuMo/SiO₂ containing 8.8 wt. % of molybdenum. At temperature 350 °C NiCu/SiO₂ and NiCuMo/SiO2 catalysts contribute to the almost complete conversion of ethanol lignin into liquid and gaseous products, and the yield of solid products does not exceed 1 wt. %. In liquid products of catalytic conversion there is a decrease in the atomic ratio of O/C and the increase of H/C atomic ratio as compared to initial ethanol lignin due to catalytic intensification of reactions of deoxygenation and hydrogenation of lignin and products of its depolymerization. According to GPC data on the curves of molecular mass distribution (MMD) of liquid products of thermocatalytic conversion of ethanol lignin at 300 °C there are peaks with highs at 160 and 380 Da, probably related to guiacyle monomers and dimmers, respectively. From the comparison of MMD of liquid products obtained by ethanol lignin depolymerization at 300 °C over catalysts NiCu/SiO₂ and NiCuMo/SiO₂ it follows, that the introduction of molybdenum in the catalyst promotes the formation of monomeric guaiacyl products

The process of abies ethanol lignin sulfation with sulfamic acid in 1,4-dioxane medium in the presence of urea was optimized by calculation methods. The influence of such factors, as the ratio of lignin/sulfating complex (L/SC), temperature and time of the sulfation process on the sulfur content in the resulting sulfated ethanol lignin and its yield, has been established. The variance analysis of the obtained mathematical models testifies their good predictive properties. The optimal conditions of abies ethanol lignin sulfation process, which provide the formation of water-soluble sulfated lignin with a high yield (to 100 % wt.) and sulfur content (up to 7.9 % wt.), have been established. They are: temperature of 95-100 °C, the ratio L/SC 1:2,3-1:2:9 and the time of the process 119-137 minutes

Methods of organic and carbon xerogels synthesis based on the use of condensed tannins isolated from abies bark were developed. Organic gels were synthesized by sol-gel condensation of tannins with formaldehyde in a solution of ethanol in the presence of catalysts (NaOH or HCl). The final gelation products were dried by alternating low (-18 – -40 °C) and room temperature to obtain tanninformaldehyde (TF) xerogels. FTIR study indicates that the formation of xerogels was accompanied by crosslinking reactions mainly due to the formation of carbon-carbon and alkyl ether bonds. Using the method of thermogravimetry, it was found that organic TF xerogels are thermally stable up to a temperature of 295 °C and they are resistant to ignition in air at temperatures up to 600 °C and can be used as thermo- and fire-retardant materials. Carbon tannin-formaldehyde xerogels were obtained by carbonization of organic xerogels at 800 °C in an argon atmosphere. The porous structure and surface morphology of organic and carbon xerogels was studied by BET- and SEM–methods. A significant development of the specific surface area (to 483–524 m2/g)as a result of the organic xerogels carbonization was established. Using SEM, it was shown that in carbon gels a spatially cross-linked structure of polymer chains consisting of 5-10 nmsized globule particles forming nanometer-sized pores is retained

For the first time water soluble copper-containing polymers based on sulfated ethanol lignin of abies wood were obtained by the method of ion exchange. Their composition and structure were studied with the use of elemental and chemical analysis, infrared spectroscopy (IR), atomic absorption, electron paramagnetic resonance (EPR). The absence of nitrogen for copper cations in the resulting polymer indicates the complete substitution of ammonium cations in the ammonium salt of sulfated ethanol lignin. In EPR spectrum of copper-containing sulfated ethanol lignin there is a superposition of two signals. One of them belongs to isolated Cu2+ ions, the other to exchange-bound Cu2+ ions in salt-like compounds. The integral intensity of signal of isolated Cu2+ ions (anisotropic signal) and exchange-bound ions (isotropic signal) depends on the copper content in the polymer

Methods have been developed for the preparation of enterosorbents by treating crushed abies bark with the 1.5% aqueous of NaOH solution or by extraction with hexane. It was found that all obtained enterosorbents have good sorption properties with respect to gelatin and methylene blue. The highest sorption activity for methylene blue was shown by a sample, obtained by extraction of abies bark with hexane (97.0 mg/g), and for gelatin sorption activity – a sample, obtained by treatment of abies bark with alkali (225.0 mg/g). It was found that the enterosorbent, obtained by treatment of abies bark with alkali solution both at a dose of 0.15 g per kg of animal weight (g/kg) and at a dose of 0.20 g/kg and the enterosorbent, obtained by extraction of abies bark with hexane at a dose of 0.20 g/kg, have the highest efficiency for the treatment and prevention of acute experimental Escherichiosis. From the considered methods of obtaining enterosorbents from abies bark for the treatment and prevention of gastrointestinal infections of animals, it is recomended to use a method based on treatment of abies bark with alkalai solution and apply the drug in a dose of 0.15 g/kg

Carbon tannin-lignin-formaldehyde (TLF) gels were obtained for the first time by carbonization of organic xerogels synthesized by sol-gel condensation of formaldehyde with polyphenolic substances isolated from abies wood and bark – ethanol lignin and condensed tannins. The effect of the mass ratio of the tannins/lignin (T/L) components in the range 1:0 – 1:2 on the specific surface areas, porous volume, apparent density, and microstructure of carbon tannin-lignin-formaldehyde gels has been studied. It was found that the density of the carbon gels increases from 0.52 to 0.60 g/cm3 with a rises in the T/L ratio from 1:0 to 1:0.2 and 1:0.5 in the initial gel and then decreases to 0.20 and 0.13 g/cm3 with an increase in the lignin content to T/L ratios of 1:1 and 1:2, respectively. The study of the porous structure of carbon gels by the BET method showed that the carbon TLF gel obtained at a T/L ratio 1:2 is characterized by the highest specific surface area (538 m2/g). Using scanning electron microscopy, the structures of TF and TLF carbon gels have been studied. It has been established that the size of globular particles has a decisive influence on the structure of gels. The size of the globule particles increases with increasing of lignin content in the composition of the tannin-lignin-formaldehyde gel that leads to the formation of a less ordered structure of the carbon gel. The porous structure of TLF carbon gels obtained from abies polyphenolic substances can be regulated by varying the ratio of tannins:lignin. The obtained carbon gels can be used as sorbents and catalyst supports

The effect of bifunctional catalyst Pt/ZrO₂ on the yield and composition of products of abies wood and ethanol lignin hydrogenation in supercritical ethanol at temperature of 250 °C was established. In the process of abies wood hydrogenation, the catalyst Pt/ZrO₂ increases the degree of conversion of wood from 52.0 to 65.7 wt.%, the yield of liquid products from 31.0 to 38.1 wt.%,.%, and also increases the content of monomeric compounds in the liquid products. In the presence of catalyst, the cellulose content in the solid product of wood catalytic hydrogenation reaches to 77.1 wt.%, and the content of lignin and hemicelluloses decreases to 21.2 wt.% and 1.7 wt.%, respectively. In the process of ethanol lignin hydrogenation the catalyst Pt/ZrO₂ increases the degree of lignin conversion from 86.0 to 99.4 wt.%, the yield of liquid products from 75.0 to 90.0 wt.%, and also reduces the yield of solid residue from 14.0 to 0.6 wt.% and the yield of gases from 4.7 to 3.3 wt.%. Thus, the polysaccharides of wood biomass complicate the reductive depolymerization of native lignin in comparison with the depolymerization of isolated ethanol lignin. The use of the catalyst Pt/ZrO₂ makes it possible to fractionate the abies wood in supercritical ethanol at 250 °C on solid product with a high content of cellulose, as well as liquid and gaseous products from lignin and hemicelluloses

The work describes a one-stage method of cellulose obtaining from fir wood based on peroxide delignification of wood under mild conditions (100 °C, atmospheric pressure) in the presence of acetic acid, water and catalyst of 2% wt. H2SO4. The possibility of obtaining cellulose with a residual lignin content

The analysis of the literature on the spectral methods of lignins study was carried out. The most suitable spectral methods for elucidating the structural features of soluble organosolv lignins were selected. The possibilities of FTIR, 1Н NMR, 13С NMR and 2D HSQC NMR methods were demonstrated on the example of studying the structure of ethanollignins obtained from fir and aspen wood. It was established that fir and aspen lignins are G type and GS type lignins, respectively. The HSQC spectra analysis demonstrated a presence of β–O–4′, β–β′, β–5′ linkages in the ethanollignins. It was found that β–O–4′ linkages in ethanollignins from fir and aspen were partially acylated with ethoxy groups in the α-position

The toxic and corrosive mineral acids are used traditionally in the processes of plant polysaccharides hydrolysis. The use of solid acid catalysts improves the environmental safety of hydrolysis processes and simplifies the separation of the catalyst from the reaction products. The stability of solid acid catalysts based on mesoporous SBA-15 and graphite-like carbon material Sibunit-4, containing SO3Hgroups, in the process of larch arabinogalactan hydrolysis at 150 °С was studied. The compositions of the resulting hydrolysates were investigated by gas chromatography. It was established that acidmodified Sibunit-4 does not lose the catalytic activity after three cycles of hydrolysis process for a total duration of 12 hours. Modified SBA-15 catalyst was less stable at the studied conditions. The decrease of monosaccharides concentration in the hydrolysates, the changes in the structure of the catalyst and 40% loss of its weight were found after the third cycle of larch arabinogalactan hydrolysis

Composition and structure of microcrystalline cellulose (MCC) sulfates obtained by traditional and new advanced methods of MCC sulfation were compared. Data on the composition and structure of MCC sulfates synthesized in the medium of chlorosulfonic acid –1,4-dioxane and by sulfation of MCC with sulfamic acid in the presence of urea in N,N-dimethylformamide and diglyme were obtained with the use of elemental analysis, FTIR, Raman, 13C NMR, XRD, XPS, SEM and AFM methods. It was shown that MCC sulfates synthesized by new methods have more homogeneous composition and morphology as compared to sulfates obtained by known methods.

The new method of sulfated arabinogalactan modification by amino acids (glycine and ornithine) based on the ion exchange procedure was developed. The composition and structure of the reaction products obtained by interaction of sulfated arabinogalactan with amino acids were studied by elemental analysis and FTIR spectroscopy.