scholarly journals Hydrogenation of Abies Wood and Ethanol Lignin by Hydrogen in Supercritical Ethanol in the Presence of Bifunctional Catalyst Pt/ZrO₂

2019 ◽  
pp. 550-561
Author(s):  
Sergei V. Baryshnikov ◽  
Angelina V. Miroshnikova ◽  
Alexandr S. Kazachenko ◽  
Yuriy N. Malyar ◽  
Oxana P. Taran ◽  
...  
Keyword(s):  
Catalytic Hydrogenation ◽  
Bifunctional Catalyst ◽  
Cellulose Content ◽  
Solid Residue ◽  
Wood Biomass ◽  
Solid Product ◽  
Gaseous Products ◽  
Liquid Products ◽  
Supercritical Ethanol ◽  
Composition Of Products

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

scholarly journals HYDROGENATION OF ABIES WOOD AND ETHANOL-LIGNIN BY MOLECULAR HYDROGEN IN SUPERCRITI-CAL ETHANOL OVER BIFUNCTIONAL RU/C CATALYST

2019 ◽  
pp. 15-26 ◽  
Author(s):  
Aleksandr Sergeyevich Kazachenko ◽  
Sergey Viktorovich Baryshnikov ◽  
Anna Il'inichna Chudina ◽  
Yuriy Nikolayevich Malyar ◽  
Valentin Vladimirovich Sychev ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Liquid Product ◽  
Carbon Support ◽  
Bifunctional Catalyst ◽  
Ruthenium Catalyst ◽  
Solid Residue ◽  
Average Molecular Mass ◽  
Gaseous Products ◽  
Liquid Products ◽  
Oxidized Carbon

The effect of a bifunctional catalyst containing nano-dispersed ruthenium particles on an oxidized carbon support “Sibunit” on the yield and composition of products in the processes of hydrogenation of abies wood and abies ethanol-lignin in a supercritical ethanol medium at 250° C was studied. The presence of Ru/C catalyst resulted in a raise the ethanol-lignin conversion from 85 to 98 wt.%, the yield of liquid product from 75 to 85 wt.%, the yield of gases – by 1.5 times, but the yield of solid products dropped from 14 to 2.8 wt.%. Ruthenium catalyst increased the conversion of abies wood by 12.5 wt.%, but did not affect the yield of liquid products. The yield of the solid residue in the presence of the catalyst was reduced by 12.5 wt.%, and the yield of gases rose by 2.5 times. Simultaneously, the ruthenium catalyst promoted the process of hydrodeoxygenation of liquid products, diminution their average molecular mass from 1174 g/mol to 827 g/mol and the formation of monomeric and dimeric compounds with a molecular mass 193 and 426 g/mol, respectively. The solid residue of catalytic hydrogenation contained 70.1 wt.% of cellulose. Thus, the application of Ru/C catalyst in the process of hydrogenation of abies wood allowed the reductive fractionation of wood biomass into a solid cellulose product, liquid and gaseous products from lignin and hemicelluloses.

scholarly journals Fractionation of Birch Wood by Integrating Alkaline-Acid Treatments and Hydrogenation in Ethanol over a Bifunctional Ruthenium Catalyst

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1362
Author(s):  
Boris N. Kuznetsov ◽  
Sergey V. Baryshnikov ◽  
Angelina V. Miroshnikova ◽  
Aleksandr S. Kazachenko ◽  
Yuriy N. Malyar ◽  
...  
Keyword(s):  
Microcrystalline Cellulose ◽  
Catalytic Hydrogenation ◽  
Liquid Product ◽  
Gel Permeation Chromatography ◽  
Ruthenium Catalyst ◽  
Birch Wood ◽  
Gaseous Products ◽  
Liquid Products ◽  
First Time

For the first time, the fractionation of birch wood into microcrystalline cellulose, xylose and methoxyphenols is suggested based on the integration of alkali-acid pretreatments and hydrogenation in ethanol over a bifunctional Ru/C catalyst. It is established that removal of hemicelluloses during pretreatments of birch wood influences the yields of the liquid, gaseous and solid products of the non-catalytic and catalytic hydrogenation of pretreated samples in ethanol at 225 °C. The bifunctional Ru/carbon catalyst affects in different ways the conversion and yields of products of hydrogenation of the initial and acid- and alkali-pretreated birch wood. The most noticeable influence is characteristic of the hydrogenation of the acid-pretreated wood, where in contrast to the non-catalytic hydrogenation, the wood conversion and the yields of liquid products increase but the yields of the solid and gaseous products decrease. GC-MS, gel permeation chromatography and elemental analysis were used for characterization of the liquid product composition. The molecular mass distribution of the liquid products of hydrogenation of the initial and pretreated wood shifts towards the low-molecular range in the presence of the catalyst. From the GC-MS data, the contents of monomer compounds, predominantly 4-propylsyringol and 4-propanolsyringol, increase in the presence of the ruthenium catalyst. The solid products of catalytic hydrogenation of the pretreated wood contain up to 95 wt% of cellulose with the structure, similar to that of microcrystalline cellulose.

scholarly journals Depolymerization of Pine Ethanol Lignin in the Medium of Supercritical Ethanol in the Presence of Catalysts NiCu/SiO₂ and NiCuMo/SiO₂

2020 ◽  
pp. 247-259
Author(s):  
Angelina V. Miroshnikova ◽  
Sergey V. Baryshnikov ◽  
Yuriy N. Malyar
Keyword(s):  
Molecular Mass Distribution ◽  
Atomic Ratio ◽  
Complete Conversion ◽  
Gaseous Products ◽  
Composition And Structure ◽  
Maximal Yield ◽  
Liquid Products ◽  
Supercritical Ethanol ◽  
Lignin Depolymerization ◽  
Thermocatalytic Conversion

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

scholarly journals The Influence of Retention of Volatile Substances in Pyrolysis Zone of Kaa-Khemsky and Mezhegeisky Coal Deposits on Component Composition of Coal Tar

2020 ◽  
pp. 606-619
Author(s):  
Grigoriy R. Mongush ◽  
Kezhik K. Chuldum ◽  
Natalia V. Garyntseva ◽  
Boris N. Kuznetsov
Keyword(s):  
Retention Time ◽  
Coal Tar ◽  
Component Composition ◽  
Coal Pyrolysis ◽  
Solid Product ◽  
Volatile Substances ◽  
Gaseous Products ◽  
Coal Deposits ◽  
Liquid Products ◽  
Scanning Electron

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

scholarly journals Reductive Catalytic Fractionation of Flax Shive over Ru/C Catalysts

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 42
Author(s):  
Aleksandr S. Kazachenko ◽  
Valery E. Tarabanko ◽  
Angelina V. Miroshnikova ◽  
Valentin V. Sychev ◽  
Andrey M. Skripnikov ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Carbon Support ◽  
Bifunctional Catalyst ◽  
Bifunctional Catalysts ◽  
Cellulose Content ◽  
Lignin Fraction ◽  
Liquid Products ◽  
Different Characteristics ◽  
High Degree ◽  
High Cellulose

Flax shive is the main waste (up to 70 wt %) in the production of flax fiber. It represents the lignified parts of the flax stem mainly in the form of small straws. Complex processing of such wastes is a significant problem due to the heterogeneity of the chemical structure of lignin. This article presents the results of reductive catalytic fractionation (RCF) of flax shive in ethanol and isopropanol at elevated temperatures (225–250 °C) in the presence of a bifunctional catalyst (Ru/C) and molecular hydrogen. This provides solvolytic depolymerization of lignin and hemicelluloses presented in flax shive. Catalytic hydrogenation effectively stabilizes the formed lignin intermediates and prevents repolymerization reactions producing the lignin fraction with a high degree of depolymerization. RCF of flax shive produces solid products with a high cellulose content and liquid products consisting mainly of monophenolic compounds. Furthermore, the effect of different characteristics (the ruthenium content, particle size, and support acidity) of the bifunctional catalysts containing ruthenium nanoparticles supported on mesoporous, graphite-like carbon material Sibunit®-4 on the yield and composition of the products of hydrogenation of flax shive in sub- and super-critical ethanol has been studied. Bifunctional catalysts Ru/C used in the RCF of flax shive increase its conversion from 44 to 56 wt % and the yield of monophenols from 1.1 to 10.2 wt % (based on the weight of lignin in the sample). Using the best Ru/C catalyst containing 3% of Ru on oxidized at 400 °C carbon support, the high degree of delignification (up to 79.0%), cellulose yield (up to 67.2 wt %), and monophenols yield (up to 9.5 wt %) have been obtained.

scholarly journals Thermal Conversion of Flax Shives in Sub- and Supercritical Ethanol in the Presence of Ru/C Catalyst

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 970
Author(s):  
Aleksandr S. Kazachenko ◽  
Angelina V. Miroshnikova ◽  
Valery E. Tarabanko ◽  
Andrey M. Skripnikov ◽  
Yuriy N. Malyar ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Bifunctional Catalyst ◽  
Thermal Conversion ◽  
Conversion Process ◽  
Ethanol Medium ◽  
Liquid Products ◽  
Supercritical Ethanol ◽  
Flax Shives

Thermal conversion of flax shives was studied in sub- and supercritical ethanol medium at 225 and 250 °C in the presence of the bifunctional catalyst 3% Ru/C. The use of 3% Ru/C catalyst in the process of thermal conversion of flax shives in supercritical ethanol was found to increase the conversion of the shives by 27% and the yield of liquid products by 10%. The use of 3% Ru/C catalyst in sub- and supercritical ethanol led to the destruction of both lignin and cellulose. The degree of delignification in the non-catalytic thermal conversion increased upon transition from subcritical (225 °C) to supercritical (250 °C) conditions. Main monomeric products of the thermal conversion process were guaiacylpropene or guaiacylpropane depending on the process temperature. In the presence of Ru/C catalyst, the molecular weight distribution was shifted towards an increase in the content of monomeric compounds in the liquid products.

Study of the Kinetics of Thermal Destruction of Crossed Polyethylene

2019 ◽  
Vol 5 (12) ◽  
pp. 37-46
Author(s):  
K. Chalov ◽  
Yu. Lugovoy ◽  
Yu. Kosivtsov ◽  
E. Sulman
Keyword(s):  
Total Yield ◽  
Calorific Value ◽  
High Heat ◽  
Process Temperature ◽  
Optimum Process ◽  
Quantitative Composition ◽  
Pyrolysis Gas ◽  
Gaseous Products ◽  
Liquid Products ◽  
Kinetics Of

This paper presents a study of the process of thermal degradation of crosslinked polyethylene. The kinetics of polymer decomposition was studied by thermogravimetry. Crosslinked polyethylene showed high heat resistance to temperatures of 400 °C. The temperature range of 430–500 °C was determined for the loss of the bulk of the sample. According to thermogravimetric data, the decomposition process proceeds in a single stage and includes a large number of fracture, cyclization, dehydrogenation, and other reactions. The process of pyrolysis of a crosslinked polymer in a stationary-bed metal reactor was investigated. The influence of the process temperature on the yield of solid, liquid, and gaseous pyrolysis products was investigated. The optimum process temperature was 500 °C. At this temperature, the yield of liquid and gaseous products was 85.0 and 12.5% (mass.), Respectively. Samples of crosslinked polyester decomposed almost completely. The amount of carbon–containing residue was 3.5% by weight of the feedstock. With increasing temperature, the yield of liquid products decreased slightly and the yield of gaseous products increased, but their total yield did not increase. For gaseous products, a qualitative and quantitative composition was determined. The main components of the pyrolysis gas were hydrocarbons C1–C4. The calorific value of pyrolysis gas obtained at a temperature of 500 °C was 17 MJ/m3. Thus, the pyrolysis process can be used to process crosslinked polyethylene wastes to produce liquid hydrocarbons and combustible gases.

MANUFACTURING GASEOUS PRODUCTS BY PYROLYSIS MICROALGAE BIOMASS

2019 ◽  
pp. 23-34
Author(s):  
N. I. Chernova ◽  
S. V. Kiseleva ◽  
O. M. Larina ◽  
G. A. Sytchev
Keyword(s):  
Raw Materials ◽  
Renewable Energy Sources ◽  
High Energy ◽  
Initial Mass ◽  
Solid Residue ◽  
Algae Biomass ◽  
Gaseous Products ◽  
Microalgae Biomass ◽  
Pyrolysis Liquid ◽  
Pyrolysis Gases

Algae biomass is considered as an alternative raw material for the production of biofuels. The search for new types of raw materials, including high-energy types of microalgae, remains relevant, since the share of motor fuels in the structure of the global fuel and energy balance remains consistently high (about 35%), and the price of oil is characterized by high volatility. The authors have considered the advantages of microalgae as sources of raw materials for fuel production. Biochemical and thermochemical conversion are proposed as technologies for their processing. This paper presents the results of the study of the pyrolysis of the biomass of clonal culture of blue-green microalgae / cyanobacteriumArthrospira platensis rsemsu 1/02-Pfrom the collection of the Research Laboratory of Renewable Energy Sources of the Lomonosov Moscow State University. An experiment to study the process of pyrolysis of microalgae biomass was carried out at the experimental facility of the Institute of High Temperatures RAS in pure nitrogen grade 6.0 to create an oxygen-free environment with a linear heating rate of 10 ºС / min from room temperature to 1000 ºС. The whole process of pyrolysis proceeded in the field of endothermy. The specific amounts of solid residue, pyrolysis liquid and gaseous products were experimentally determined. As a result of the pyrolysis of microalgae biomass weighing 15 g, the following products were obtained: 1) coal has the mass of the solid residue is 2.68 g, or 17.7% of the initial mass of the microalgae (while 9.3% of the initial mass of the microalgae remained in the reactor); 2) pyrolysis liquid – weight 3.3 g, or 21.9% of the initial weight; 3) non-condensable pyrolysis gases – weight 1.15 l. The specific volumetric gas yield (the amount of gas released from 1 kg of the starting material) was 0.076 Nm3/ kg. The analysis of the composition and specific volume yield of non-condensable pyrolysis gases formed in the process of pyrolysis, depending on temperature. It is shown that with increasing temperature, the proportion of highcalorie components of the gas mixture (hydrogen, methane and carbon monoxide) increases. The calorific value of the mixture of these gases has been estimated.

scholarly journals The Effect of Carbonates and Silicates on the Cracking of a Mixture of Fuel Oil and Mechanically Activated Oil Shale

2021 ◽  
pp. 234-241
Author(s):  
Marina V. Mozhayskaya ◽  
Galina S. Pevneva ◽  
Vladimir G. Surkov
Keyword(s):  
Oil Shale ◽  
Fractional Composition ◽  
Fuel Oil ◽  
Gaseous Products ◽  
Liquid Products ◽  
Mineral Components ◽  
Diesel Fractions

The study cracking of a mixture of mechanically activated oil shale (MO OSh) and fuel oil, a mixture of demineralized MO GS and fuel oil has been investigated. The data on the composition of liquid products showed that after the removal of mineral components, oil shale is more easily destroyed due to the release of kerogen. It is shown that in the obtained liquid products of the cracking of the mixture of fuel oil – demineralized MO OSh, the proportion of oils increases to 74.6 % wt. In the composition of gaseous products of cracking, the amount of hydrogen, methane and ethane is noticeably reduced. According to the data on the fractional composition of liquid products, it was found that during the cracking of mixtures of fuel oil and MO HS, after the removal of carbonates and silicates, the proportion of gasoline and diesel fractions inc

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