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 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

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.

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 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

scholarly journals Study of pyrolysis of high density polyethylene in the open system and estimation of its capability for co-pyrolysis with lignite

2018 ◽  
Vol 83 (7-8) ◽  
pp. 923-940
Author(s):  
Ivan Kojic ◽  
Achim Bechtel ◽  
Friedrich Kittinger ◽  
Nikola Stevanovic ◽  
Marko Obradovic ◽  
...  
Keyword(s):  
Open System ◽  
High Density Polyethylene ◽  
Synergetic Effect ◽  
Polar Compounds ◽  
High Density ◽  
Feed Stream ◽  
Gaseous Products ◽  
Liquid Products ◽  
Plastic Bag ◽  
Pre Treatment

Pyrolysis of high density polyethylene (HDPE) in the open system was studied. A plastic bag for food packing was used as a source of HDPE. Pyrolysis was performed at temperatures of 400, 450 and 500?C, which were chosen based on thermogravimetric analysis. The HDPE pyrolysis yielded liquid, gaseous and solid products. Temperature rise resulted in the increase of conversion of HDPE into liquid and gaseous products. The main constituents of liquid pyrolysates are 1-n-alkenes, n-alkanes and terminal n-dienes. The composition of liquid products indicates that the performed pyrolysis of HDPE could not serve as a standalone operation for the production of gasoline or diesel, but preferably as a pre-treatment to yield a product to be blended into a refinery or petrochemical feed stream. The advantage of a liquid pyrolysate in comparison to crude oil is the extremely low content of aromatic hydrocarbons and the absence of polar compounds. The gaseous products have desirable composition and consist mainly of methane and ethene. The solid residues do not produce ash by combustion and have high calorific values. Co-pyrolysis of HDPE with mineral-rich lignite indicated positive synergetic effect at 450 and 500?C, which is reflected through the increased experimental yields of liquid and gaseous products in comparison to theoretical ones.

The effect of a nickel-containing catalyst on the tar carbonization process

2021 ◽  
Vol 1 (1-2) ◽  
pp. 7-14
Author(s):  
V. V. Chesnokov ◽  
A. S. Chichkan ◽  
V. N. Parmon
Keyword(s):  
Gas Phase ◽  
Fractional Composition ◽  
Polyaromatic Hydrocarbons ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Gaseous Products ◽  
Hydrocarbon Chains ◽  
Liquid Products ◽  
Sulfur Containing ◽  
Diesel Fractions

Tar carbonization was studied in the absence or presence of the 7% Ni/CNT catalyst. It was shown that tar carbonization at a temperature of 350 °С without the catalyst leads to the formation of gaseous and liquid products and oil coke. Thermolysis products are formed via the separation of lateral hydrocarbon chains from the initial polyaromatic hydrocarbons. Gaseous products consist of С1-С6 hydrocarbons and sulfur-containing gases H2S and COS. Fractional composition of the liquid thermolysis products was studied. It was found that 50 % of the liquid products are represented by gasoline and diesel fractions. The 7% Ni/CNT catalyst was prepared by impregnation. The effect of this catalyst on the tar carbonization in the temperature range of 300–550 °С was studied. The addition of the 7% Ni/CNT catalyst to tar increased its yield and decreased the sulfur content due to partial conversion of sulfur to hydrogen sulfide and COS, which are removed with the gas phase. The electron microscopy study showed that the oil coke obtained upon catalytic tar carbonization is reinforced with carbon nanotubes.

scholarly journals Atomic layer deposition and properties of ZrO2/Fe2O3 thin films

2018 ◽  
Vol 9 ◽  
pp. 119-128 ◽  
Author(s):  
Kristjan Kalam ◽  
Helina Seemen ◽  
Peeter Ritslaid ◽  
Mihkel Rähn ◽  
Aile Tamm ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Atomic Ratio ◽  
Thin Solid Films ◽  
Solid Films ◽  
Electrical And Magnetic Properties ◽  
Layer Deposition ◽  
Composition And Structure ◽  
A Charge

Thin solid films consisting of ZrO2 and Fe2O3 were grown by atomic layer deposition (ALD) at 400 °C. Metastable phases of ZrO2 were stabilized by Fe2O3 doping. The number of alternating ZrO2 and Fe2O3 deposition cycles were varied in order to achieve films with different cation ratios. The influence of annealing on the composition and structure of the thin films was investigated. Additionally, the influence of composition and structure on electrical and magnetic properties was studied. Several samples exhibited a measurable saturation magnetization and most of the samples exhibited a charge polarization. Both phenomena were observed in the sample with a Zr/Fe atomic ratio of 2.0.

scholarly journals THERMOCATALYTIC DEGRADATION OF POLYPROPYLENE IN PRESENCE OF ALUMINUM SILICATES

2020 ◽  
Vol 63 (6) ◽  
pp. 85-89
Author(s):  
Lyubov V. Furda ◽  
Dmitry E. Smalchenko ◽  
Evgeny N. Titov ◽  
Olga E. Lebedeva
Keyword(s):  
Aluminum Content ◽  
Sol Gel ◽  
Fixed Bed ◽  
Textural Properties ◽  
Fixed Bed Reactor ◽  
Alternative Source ◽  
Catalyst Composition ◽  
Developed Surface ◽  
Liquid Products ◽  
Thermocatalytic Conversion

The process of thermocatalytic conversion of polypropylene into liquid hydrocarbons using amorphous aluminum silicates with aluminum content of 1.6-12.9 wt.% as catalysts was studied. The aluminum silicates were synthesized by sol-gel method using hydrolysis of tetraethoxysilane in a presence of aluminum salt at pH=9. All samples possessed acidic sites with pKa value of 3.46-5.00 and had a developed surface. Textural properties of the aluminum silicates were determined. Thermocatalytic conversion of polypropylene was carried out in a flow fixed-bed reactor with a fixed layer of the mixture of the catalyst and the reagent at a mass ratio of polymer : catalyst of 3 : 1 in argon atmosphere with a gradual rise of temperature in the range of 300 – 450 ºС. The sample of silica, which did not contain aluminum, was demonstrated to be inactive in polypropylene degradation, while other catalysts provided conversion of polypropylene into liquid products. The highest yield of liquid products was 80% for a catalyst with an aluminum content of 8.1 wt.%. According to the results of GLC saturated hydrocarbons were identified among the products for all samples. The effect of the concentration of acidic centers on the chemical and fractional composition of the target products was shown. For the studied aluminum silicates with the same pKa values, an increase in the aluminum content favored the formation of a lighter hydrocarbon fraction. For the catalyst with the highest aluminum content the n-alkanes of С5-С10 composition were identified. These products were closest to gasoline oil fraction. This provides a possibility to consider secondary polyolefins as an alternative source of motor fuels. An influence of catalyst composition on maximal temperature of polyethylene degradation was determined by differential thermal analysis.

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 Thermo-chemical analysis and modeling of combustion of waste pyrolysis gaseous products

2021 ◽  
Vol 247 ◽  
pp. 01056
Author(s):  
Alexey Demin ◽  
Grigorii Pavlov ◽  
Mansur Khasiyatullov
Keyword(s):  
Thermal Destruction ◽  
Raw Materials ◽  
Solid Carbon ◽  
Mass Ratio ◽  
Temperature Level ◽  
Pyrolysis Products ◽  
Gaseous Products ◽  
Liquid Products ◽  
Joint Pyrolysis ◽  
Pyrolysis Gases

The results of the study of joint pyrolysis of various types of waste (municipal solid waste, plastic waste, etc.) are presented. Preliminarily crushed and dried wastes were fed into the pyrolysis chamber of the model experimental setup. Thermal energy required for heating raw materials and carrying out their thermal destruction was obtained by burning a part of the pyrolysis gases. The rest of these gases were removed from the pyrolysis chamber and cooled. The temperature in the pyrolysis zone was about 650 °C. Plant productivity was up to 500 kg/h. The target product was the liquid phase, which is a mixture of hydrocarbon compounds. When organizing the processes, the yield of solid carbon residue was minimized. The obtained mass ratio of the final gas/liquid products was approximately equal to 1/6. Experimental results of the analysis of the chemical composition of the gas and liquid fractions are presented. The results of modeling the combustion of pyrolysis products at different amounts of supplied air are also shown. The operating parameters at which the optimum temperature level in the pyrolysis zone is maintained are numerically determined and recommended.

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