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Janez Levec - One of the best experts on this subject based on the ideXlab platform.
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Simultaneous Liquefaction and Hydrodeoxygenation of Lignocellulosic Biomass over NiMo/Al2O3, Pd/Al2O3, and Zeolite y Catalysts in Hydrogen Donor Solvents
ChemCatChem, 2016Co-Authors: Miha Grilc, Blaž Likozar, Janez LevecAbstract:The one-step solvolysis and hydro-treatment of oak, fir and beech sawdust was studied in a slurry reactor using tetralin, phenol and glycerol as solvents and representative heterogeneous catalysts used in the petrochemical industry for hydrogenolysis (the sulfide form of NiMo/Al2O3), hydrogenation (Pd/Al2O3) or fluid catalytic cracking (zeolite Y). Deoxyliquefaction products of cellulose, hemicellulose and lignin were characterised in terms of solvent fractionation, FTIR and diffuse reflectance infrared Fourier transform spectroscopy, elemental analysis and an innovative method for particle size distribution and mean grain size determination by SEM image processing. A new lumped kinetic model was developed according to the reaction mechanisms, which contain wood de-polymerisation, Decarbonylation, decarboxylation and demethanation, tar phase hydrodeoxygenation by molecular and in situ generated hydrogen, as well as charring inhibition by free-radical stabilisation hydrogen transfer.
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kinetic model of homogeneous lignocellulosic biomass solvolysis in glycerol and imidazolium based ionic liquids with subsequent heterogeneous hydrodeoxygenation over nimo al2o3 catalyst
Catalysis Today, 2015Co-Authors: Miha Grilc, Blaž Likozar, Janez LevecAbstract:Abstract Solvolysis of wood, cellulose, hemicellulose and lignin in glycerol was investigated in the presence of homogeneous imidazolium-based ionic liquid (IL) catalysts, where the influence of the IL type, reaction time, temperature and mass transfer limitations on decomposition rate was investigated. The selection of anions (acetate, hydrogen sulphate or chloride/metal halide complex to form a Lewis acid) and cations (butyl-, methyl- or allyl-functionalised imidazolium) importantly influenced conversion, which was as high as 64.4 and 91.5 wt% for the beech wood liquefaction at 150 and 200 °C within 60 min. By following the mass of solid particles and their specific surface area (BET method) as a function of time and temperature, a novel kinetic model for the solvolysis of biomass and its components was developed, where reactive surface area is a key parameter that dictates the rate of solid–liquid reaction; kinetic model also considered different depolymerisation reactivity of main three wood components. Liquefied biomass was consequently hydrodeoxygenated at 225–275 °C in the presence of commercially available sulphide-form NiMo/γ-Al2O3 catalyst. Rates and selectivity of hydrogenolysis, Decarbonylation, decarboxylation, hydrogenation and (hydro)cracking were followed and modelled by using previously developed lumped kinetic model, based on the Fourier transformed infrared spectroscopy (FTIR) analysis. The oxygen content of the oil phase of was less than 1.7 wt%.
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Hydrotreatment of solvolytically liquefied lignocellulosic biomass over NiMo/Al2O3 catalyst: Reaction mechanism, hydrodeoxygenation kinetics and mass transfer model based on FTIR
Biomass & Bioenergy, 2014Co-Authors: Miha Grilc, Blaž Likozar, Janez LevecAbstract:Abstract Raw residual wood biomass, containing cellulose, hemicellulose and lignin, was liquefied at low temperature by ultrasound-assisted solvolysis and acidolysis by glycerol, diethylene glycol and p -toluenesulfonic acid. Liquefied biomass was consequently upgraded by hydrotreatment utilizing heterogeneous catalysis over NiMo/Al 2 O 3 bifunctional catalyst. Effects of temperature (200−350 °C), heating rate (2.5–10.0 K min −1 ), hydrogen/nitrogen pressure (2−8 MPa), mixing (250−1000 min −1 ), hydrogen donor solvent (tetralin) and catalyst contents on deoxygenation were established. Reactions of liquefaction products, such as levulinic acid, were quantified based on their functional groups by Fourier transform infrared spectroscopy, whereas catalyst was examined by scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction analysis (XRD). Chemical kinetics of hydrodeoxygenation (HDO), Decarbonylation and decarboxylation were determined by originally developed lumped model, based on reaction mechanisms and pathways, while the external mass transfer resistance proved to be negligible under the applied hydrodynamic conditions. The presence of hydrocracking reactions was confirmed by a decrease in product viscosity, and the upgrade for energetic or fuel applications by measurements of calorific value.
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hydrotreatment of solvolytically liquefied lignocellulosic biomass over nimo al2o3 catalyst reaction mechanism hydrodeoxygenation kinetics and mass transfer model based on ftir
Biomass & Bioenergy, 2014Co-Authors: Miha Grilc, Blaž Likozar, Janez LevecAbstract:Abstract Raw residual wood biomass, containing cellulose, hemicellulose and lignin, was liquefied at low temperature by ultrasound-assisted solvolysis and acidolysis by glycerol, diethylene glycol and p -toluenesulfonic acid. Liquefied biomass was consequently upgraded by hydrotreatment utilizing heterogeneous catalysis over NiMo/Al 2 O 3 bifunctional catalyst. Effects of temperature (200−350 °C), heating rate (2.5–10.0 K min −1 ), hydrogen/nitrogen pressure (2−8 MPa), mixing (250−1000 min −1 ), hydrogen donor solvent (tetralin) and catalyst contents on deoxygenation were established. Reactions of liquefaction products, such as levulinic acid, were quantified based on their functional groups by Fourier transform infrared spectroscopy, whereas catalyst was examined by scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction analysis (XRD). Chemical kinetics of hydrodeoxygenation (HDO), Decarbonylation and decarboxylation were determined by originally developed lumped model, based on reaction mechanisms and pathways, while the external mass transfer resistance proved to be negligible under the applied hydrodynamic conditions. The presence of hydrocracking reactions was confirmed by a decrease in product viscosity, and the upgrade for energetic or fuel applications by measurements of calorific value.
Miha Grilc - One of the best experts on this subject based on the ideXlab platform.
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Simultaneous Liquefaction and Hydrodeoxygenation of Lignocellulosic Biomass over NiMo/Al2O3, Pd/Al2O3, and Zeolite y Catalysts in Hydrogen Donor Solvents
ChemCatChem, 2016Co-Authors: Miha Grilc, Blaž Likozar, Janez LevecAbstract:The one-step solvolysis and hydro-treatment of oak, fir and beech sawdust was studied in a slurry reactor using tetralin, phenol and glycerol as solvents and representative heterogeneous catalysts used in the petrochemical industry for hydrogenolysis (the sulfide form of NiMo/Al2O3), hydrogenation (Pd/Al2O3) or fluid catalytic cracking (zeolite Y). Deoxyliquefaction products of cellulose, hemicellulose and lignin were characterised in terms of solvent fractionation, FTIR and diffuse reflectance infrared Fourier transform spectroscopy, elemental analysis and an innovative method for particle size distribution and mean grain size determination by SEM image processing. A new lumped kinetic model was developed according to the reaction mechanisms, which contain wood de-polymerisation, Decarbonylation, decarboxylation and demethanation, tar phase hydrodeoxygenation by molecular and in situ generated hydrogen, as well as charring inhibition by free-radical stabilisation hydrogen transfer.
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kinetic model of homogeneous lignocellulosic biomass solvolysis in glycerol and imidazolium based ionic liquids with subsequent heterogeneous hydrodeoxygenation over nimo al2o3 catalyst
Catalysis Today, 2015Co-Authors: Miha Grilc, Blaž Likozar, Janez LevecAbstract:Abstract Solvolysis of wood, cellulose, hemicellulose and lignin in glycerol was investigated in the presence of homogeneous imidazolium-based ionic liquid (IL) catalysts, where the influence of the IL type, reaction time, temperature and mass transfer limitations on decomposition rate was investigated. The selection of anions (acetate, hydrogen sulphate or chloride/metal halide complex to form a Lewis acid) and cations (butyl-, methyl- or allyl-functionalised imidazolium) importantly influenced conversion, which was as high as 64.4 and 91.5 wt% for the beech wood liquefaction at 150 and 200 °C within 60 min. By following the mass of solid particles and their specific surface area (BET method) as a function of time and temperature, a novel kinetic model for the solvolysis of biomass and its components was developed, where reactive surface area is a key parameter that dictates the rate of solid–liquid reaction; kinetic model also considered different depolymerisation reactivity of main three wood components. Liquefied biomass was consequently hydrodeoxygenated at 225–275 °C in the presence of commercially available sulphide-form NiMo/γ-Al2O3 catalyst. Rates and selectivity of hydrogenolysis, Decarbonylation, decarboxylation, hydrogenation and (hydro)cracking were followed and modelled by using previously developed lumped kinetic model, based on the Fourier transformed infrared spectroscopy (FTIR) analysis. The oxygen content of the oil phase of was less than 1.7 wt%.
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Hydrotreatment of solvolytically liquefied lignocellulosic biomass over NiMo/Al2O3 catalyst: Reaction mechanism, hydrodeoxygenation kinetics and mass transfer model based on FTIR
Biomass & Bioenergy, 2014Co-Authors: Miha Grilc, Blaž Likozar, Janez LevecAbstract:Abstract Raw residual wood biomass, containing cellulose, hemicellulose and lignin, was liquefied at low temperature by ultrasound-assisted solvolysis and acidolysis by glycerol, diethylene glycol and p -toluenesulfonic acid. Liquefied biomass was consequently upgraded by hydrotreatment utilizing heterogeneous catalysis over NiMo/Al 2 O 3 bifunctional catalyst. Effects of temperature (200−350 °C), heating rate (2.5–10.0 K min −1 ), hydrogen/nitrogen pressure (2−8 MPa), mixing (250−1000 min −1 ), hydrogen donor solvent (tetralin) and catalyst contents on deoxygenation were established. Reactions of liquefaction products, such as levulinic acid, were quantified based on their functional groups by Fourier transform infrared spectroscopy, whereas catalyst was examined by scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction analysis (XRD). Chemical kinetics of hydrodeoxygenation (HDO), Decarbonylation and decarboxylation were determined by originally developed lumped model, based on reaction mechanisms and pathways, while the external mass transfer resistance proved to be negligible under the applied hydrodynamic conditions. The presence of hydrocracking reactions was confirmed by a decrease in product viscosity, and the upgrade for energetic or fuel applications by measurements of calorific value.
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hydrotreatment of solvolytically liquefied lignocellulosic biomass over nimo al2o3 catalyst reaction mechanism hydrodeoxygenation kinetics and mass transfer model based on ftir
Biomass & Bioenergy, 2014Co-Authors: Miha Grilc, Blaž Likozar, Janez LevecAbstract:Abstract Raw residual wood biomass, containing cellulose, hemicellulose and lignin, was liquefied at low temperature by ultrasound-assisted solvolysis and acidolysis by glycerol, diethylene glycol and p -toluenesulfonic acid. Liquefied biomass was consequently upgraded by hydrotreatment utilizing heterogeneous catalysis over NiMo/Al 2 O 3 bifunctional catalyst. Effects of temperature (200−350 °C), heating rate (2.5–10.0 K min −1 ), hydrogen/nitrogen pressure (2−8 MPa), mixing (250−1000 min −1 ), hydrogen donor solvent (tetralin) and catalyst contents on deoxygenation were established. Reactions of liquefaction products, such as levulinic acid, were quantified based on their functional groups by Fourier transform infrared spectroscopy, whereas catalyst was examined by scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction analysis (XRD). Chemical kinetics of hydrodeoxygenation (HDO), Decarbonylation and decarboxylation were determined by originally developed lumped model, based on reaction mechanisms and pathways, while the external mass transfer resistance proved to be negligible under the applied hydrodynamic conditions. The presence of hydrocracking reactions was confirmed by a decrease in product viscosity, and the upgrade for energetic or fuel applications by measurements of calorific value.
Anil K. Sinha - One of the best experts on this subject based on the ideXlab platform.
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Transportation fuels from co-processing of waste vegetable oil and gas oil mixtures
Biomass and Bioenergy, 2013Co-Authors: Bharat S. Rana, Rashmi Tiwari, Madhukar O. Garg, Rakesh K. Joshi, Rohit Kumar, Rakesh Kumar, Anil K. SinhaAbstract:Hydroprocessing catalysts, sulfided Ni-W (on mesoporous silica-alumina) and Ni-Mo (on mesoporous γ-alumina), under typical hydroprocessing conditions, can very effectively produce liquid fuel from mixtures of waste vegetable oil and refinery gas oil. The acidity of the catalyst controls the relative amount of diesel range (straight chain) alkanes and cracked lighter products. The yield of diesel range (250-380°C) product varied between 60 and 90%, while kerosene (jet) range product varied between 10 and 35% depending upon the reaction conditions and type of catalyst used. The hydrodeoxygenation pathway for oxygen removal from triglyceride seems to be favored over the Ni-Mo catalyst, while decarboxylation+Decarbonylation pathway is favored over the Ni-W catalyst and the respective pathways becomes more dominant with increasing vegetable-oil content in the feed. Vegetable oil conversion does not adversely influence hydrodesulfurization of gas oil indicating viability of co-processing. The activation energy for overall S-removal is much lower than that for overall O-removal. Density and acidity (TAN) of the products meet the required specification and cetane number is better than that for pure diesel. © 2013 Elsevier Ltd.
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hydrotreating and hydrocracking catalysts for processing of waste soya oil and refinery oil mixtures
Catalysis Communications, 2011Co-Authors: Rashmi Tiwari, Bharat S. Rana, Rohit Kumar, Rakesh Kumar, Deepak Verma, Rakesh Kumar Joshi, M O Garg, Anil K. SinhaAbstract:Abstract Mesoporous SiO 2 –Al 2 O 3 and Al 2 O 3 were used as supports to prepare hydrocracking (sulfided Ni–W/SiO 2 –Al 2 O 3 ) and hydrotreating (sulfided Ni–Mo/Al 2 O 3 ) catalysts. These hydroprocessing catalysts were used under typical hydroprocessing conditions to convert waste soya-oil mixtures with refinery-oil into saturated hydrocarbons. The hydrocracking catalyst was more selective for the kerosene range (140–250 °C) hydrocarbons while the less acidic hydrotreating catalyst was more selective for the diesel range (250–380 °C) hydrocarbons. The hydrodeoxygenation pathway for oxygen removal from triglycerides seems to be favored over the hydrotreating catalyst, while decarboxylation + Decarbonylation pathway is favored over the hydrocracking catalyst.
Krystyna Porzyckasemczuk - One of the best experts on this subject based on the ideXlab platform.
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hydrodeoxygenation decarboxylation and Decarbonylation reactions while co processing vegetable oils over a nimo hydrotreatment catalyst part i thermal effects theoretical considerations
Fuel, 2014Co-Authors: łukasz Jeczmionek, Krystyna PorzyckasemczukAbstract:Abstract The presented work covers theoretical considerations regarding the total heat effects associated with vegetable oil hydroconversion to form n-paraffinic diesel fuel biocomponents relative to the process conditions. The hydroconversion of fatty acid triglycerides is a highly exothermic process. The hydrodeoxygenation, decarboxylation and Decarbonylation of fatty acids are the basic reactions occurring during this process. The hydrodeoxygenation and decarboxylation reactions are exothermic, while Decarbonylation exhibits a relatively modest endothermic effect. A similar situation applies to the secondary reactions: rWGSR – reverse water gas shift reaction (endothermic) and CO methanation (strongly exothermic). The contribution of each reaction depends on the process conditions, particularly the hydrogen pressure. Theoretical considerations suggest that the total heat effect in the reactor should be similar under different pressure conditions. The heat effects connected to a particular hydroconversion reaction (main and secondary) may compensate one another.
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hydrodeoxygenation decarboxylation and Decarbonylation reactions while co processing vegetable oils over nimo hydrotreatment catalyst part ii thermal effects experimental results
Fuel, 2014Co-Authors: łukasz Jeczmionek, Krystyna PorzyckasemczukAbstract:Abstract Two paraffinic feedstocks containing 20 vol.% of significantly different vegetable oils (olive or corn oil) were subjected to hydroconversion over a commercial NiMo catalyst under two different pressures (3.0 or 6.0 MPa), at 320 °C, with liquid hourly space velocity (LHSV) of 1.0 h −1 and hydrogen/feedstock ratio equal to 300 N m 3 /m 3 . Changes in the hydroconversion pressure significantly affect the contribution of the major (hydrodeoxygenation, decarboxylation and Decarbonylation) and secondary reactions (strongly exothermic methanation and endothermic reverse water gas shift reaction (rWGSR)). Nevertheless, the total heat effect in the reactor did not differ significantly. The heat effects changed noticeably when different vegetable oils were used as feedstocks. It was found that the differences in the total heat effects noted during hydroconversion for the two vegetable oils depend on the unsaturated fatty acid contents.
Blaž Likozar - One of the best experts on this subject based on the ideXlab platform.
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Simultaneous Liquefaction and Hydrodeoxygenation of Lignocellulosic Biomass over NiMo/Al2O3, Pd/Al2O3, and Zeolite y Catalysts in Hydrogen Donor Solvents
ChemCatChem, 2016Co-Authors: Miha Grilc, Blaž Likozar, Janez LevecAbstract:The one-step solvolysis and hydro-treatment of oak, fir and beech sawdust was studied in a slurry reactor using tetralin, phenol and glycerol as solvents and representative heterogeneous catalysts used in the petrochemical industry for hydrogenolysis (the sulfide form of NiMo/Al2O3), hydrogenation (Pd/Al2O3) or fluid catalytic cracking (zeolite Y). Deoxyliquefaction products of cellulose, hemicellulose and lignin were characterised in terms of solvent fractionation, FTIR and diffuse reflectance infrared Fourier transform spectroscopy, elemental analysis and an innovative method for particle size distribution and mean grain size determination by SEM image processing. A new lumped kinetic model was developed according to the reaction mechanisms, which contain wood de-polymerisation, Decarbonylation, decarboxylation and demethanation, tar phase hydrodeoxygenation by molecular and in situ generated hydrogen, as well as charring inhibition by free-radical stabilisation hydrogen transfer.
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kinetic model of homogeneous lignocellulosic biomass solvolysis in glycerol and imidazolium based ionic liquids with subsequent heterogeneous hydrodeoxygenation over nimo al2o3 catalyst
Catalysis Today, 2015Co-Authors: Miha Grilc, Blaž Likozar, Janez LevecAbstract:Abstract Solvolysis of wood, cellulose, hemicellulose and lignin in glycerol was investigated in the presence of homogeneous imidazolium-based ionic liquid (IL) catalysts, where the influence of the IL type, reaction time, temperature and mass transfer limitations on decomposition rate was investigated. The selection of anions (acetate, hydrogen sulphate or chloride/metal halide complex to form a Lewis acid) and cations (butyl-, methyl- or allyl-functionalised imidazolium) importantly influenced conversion, which was as high as 64.4 and 91.5 wt% for the beech wood liquefaction at 150 and 200 °C within 60 min. By following the mass of solid particles and their specific surface area (BET method) as a function of time and temperature, a novel kinetic model for the solvolysis of biomass and its components was developed, where reactive surface area is a key parameter that dictates the rate of solid–liquid reaction; kinetic model also considered different depolymerisation reactivity of main three wood components. Liquefied biomass was consequently hydrodeoxygenated at 225–275 °C in the presence of commercially available sulphide-form NiMo/γ-Al2O3 catalyst. Rates and selectivity of hydrogenolysis, Decarbonylation, decarboxylation, hydrogenation and (hydro)cracking were followed and modelled by using previously developed lumped kinetic model, based on the Fourier transformed infrared spectroscopy (FTIR) analysis. The oxygen content of the oil phase of was less than 1.7 wt%.
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Hydrotreatment of solvolytically liquefied lignocellulosic biomass over NiMo/Al2O3 catalyst: Reaction mechanism, hydrodeoxygenation kinetics and mass transfer model based on FTIR
Biomass & Bioenergy, 2014Co-Authors: Miha Grilc, Blaž Likozar, Janez LevecAbstract:Abstract Raw residual wood biomass, containing cellulose, hemicellulose and lignin, was liquefied at low temperature by ultrasound-assisted solvolysis and acidolysis by glycerol, diethylene glycol and p -toluenesulfonic acid. Liquefied biomass was consequently upgraded by hydrotreatment utilizing heterogeneous catalysis over NiMo/Al 2 O 3 bifunctional catalyst. Effects of temperature (200−350 °C), heating rate (2.5–10.0 K min −1 ), hydrogen/nitrogen pressure (2−8 MPa), mixing (250−1000 min −1 ), hydrogen donor solvent (tetralin) and catalyst contents on deoxygenation were established. Reactions of liquefaction products, such as levulinic acid, were quantified based on their functional groups by Fourier transform infrared spectroscopy, whereas catalyst was examined by scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction analysis (XRD). Chemical kinetics of hydrodeoxygenation (HDO), Decarbonylation and decarboxylation were determined by originally developed lumped model, based on reaction mechanisms and pathways, while the external mass transfer resistance proved to be negligible under the applied hydrodynamic conditions. The presence of hydrocracking reactions was confirmed by a decrease in product viscosity, and the upgrade for energetic or fuel applications by measurements of calorific value.
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hydrotreatment of solvolytically liquefied lignocellulosic biomass over nimo al2o3 catalyst reaction mechanism hydrodeoxygenation kinetics and mass transfer model based on ftir
Biomass & Bioenergy, 2014Co-Authors: Miha Grilc, Blaž Likozar, Janez LevecAbstract:Abstract Raw residual wood biomass, containing cellulose, hemicellulose and lignin, was liquefied at low temperature by ultrasound-assisted solvolysis and acidolysis by glycerol, diethylene glycol and p -toluenesulfonic acid. Liquefied biomass was consequently upgraded by hydrotreatment utilizing heterogeneous catalysis over NiMo/Al 2 O 3 bifunctional catalyst. Effects of temperature (200−350 °C), heating rate (2.5–10.0 K min −1 ), hydrogen/nitrogen pressure (2−8 MPa), mixing (250−1000 min −1 ), hydrogen donor solvent (tetralin) and catalyst contents on deoxygenation were established. Reactions of liquefaction products, such as levulinic acid, were quantified based on their functional groups by Fourier transform infrared spectroscopy, whereas catalyst was examined by scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction analysis (XRD). Chemical kinetics of hydrodeoxygenation (HDO), Decarbonylation and decarboxylation were determined by originally developed lumped model, based on reaction mechanisms and pathways, while the external mass transfer resistance proved to be negligible under the applied hydrodynamic conditions. The presence of hydrocracking reactions was confirmed by a decrease in product viscosity, and the upgrade for energetic or fuel applications by measurements of calorific value.
