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Melaz Tayakoutfayolle - One of the best experts on this subject based on the ideXlab platform.
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modeling of atmospheric and vacuum petroleum Residue Hydroconversion in a slurry semi batch reactor study of hydrogen consumption
Fuel Processing Technology, 2019Co-Authors: Pedro Alvarez, Christophe Geante, Arbara Owning, Tim Janse, Maxime Lacroi, Isabelle Pitaul, Melaz TayakoutfayolleAbstract:Abstract In this work, Arabian light atmospheric Residue and Safaniya vacuum Residue were hydroconverted in a slurry phase semi-batch stirred tank reactor at 15 MPa for a wide range of temperatures (420–440 °C) and reaction times up to 4 h. Experimental data was used to develop a semi-batch reactor model including vapor-liquid equilibrium, gas-liquid mass transfer and gas phase hydrodynamics. Mass transfer and kinetic parameters were estimated by minimizing not only the total masses of products but also the outlet gas flow dynamics. Mass transfer and hydrogen consumption were compared against former studies using a batch reactor, a continuous stirred tank reactor and work by other authors, reported in the literature. Higher hydrogen consumption was achieved with the semi-batch reactor and no hydrogen mass transfer limitation was observed. Therefore, it was concluded that this setup is more suited and reliable for studying the chemical kinetics of slurry-phase Hydroconversion of petroleum Residues and permits improved representation of the role of hydrogen compared with current models.
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simulation of petroleum Residue Hydroconversion in a continuous pilot unit using batch reactor experiments and a cold mock up
Industrial & Engineering Chemistry Research, 2014Co-Authors: Tim Jansen, Christophe Geantet, Maxime Lacroix, Marie Ropars, Dimitri Guerry, E Leclerc, Melaz TayakoutfayolleAbstract:The kinetics of atmospheric petroleum Residue Hydroconversion with a dispersed catalyst was studied. A methodology has been developed in order to transpose the chemical kinetics (reaction network, stoichiometry, and kinetic constants) obtained with a batch reactor by Nguyen et al. to a continuous reactor [Nguyen, T. S.; Tayakout-Fayolle, M.; Ropars, M.; Geantet, C. Chem. Eng. Sci. 2013, 94, 214]. Their five-lump kinetic model takes into account vapor–liquid mass transfer, vapor–liquid equilibriums, and hydrogen consumption. Consequently, hydrodynamics and vapor–liquid mass transfer of the micropilot unit’s reactor were studied in a cold mock-up by tracer experiments. The same thermodynamic model given by Nguyen et al. was used, and the flash calculations were performed using ProSimPlus software. Experimental data were obtained in the micropilot unit at 420, 430, and 440 °C with a dispersed catalyst for residence times of 1 and 2 h. The catalyst precursor, an oil-soluble molybdenum naphthenate, was added t...
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characterization of a continuous micro scale pilot unit for petroleum Residue Hydroconversion with dispersed catalysts hydrodynamics and performances in once through and recycling mode
Chemical Engineering Journal, 2014Co-Authors: Tim Jansen, Christophe Geantet, Maxime Lacroix, Marie Ropars, Dimitri Guerry, Delphine Gotteland, Robert Bacaud, Chantal Lorentz, Melaz TayakoutfayolleAbstract:Abstract A continuous micro-pilot unit has been designed to convert petroleum Residues with dispersed catalysts. Once-through and recycling modes can be operated. Several operating conditions (residence times and temperatures) have been investigated using the molybdenum naphthenate as catalyst precursor (600 ppm). The micro-pilot hydrodynamics has been characterized via a cold mockup by Residence Time Distribution. Whatever the mode used, the conversion, product yields and average molecular weights depends only on residence time and temperature.
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Hydroconversion of an atmospheric Residue with a dispersed catalyst in a batch reactor kinetic modeling including vapor liquid equilibrium
Chemical Engineering Science, 2013Co-Authors: Thanhso Nguye, Melaz Tayakoutfayolle, Marie Ropars, Christophe GeanteAbstract:Abstract A kinetic model was proposed to describe the atmospheric Residue Hydroconversion with a dispersed catalyst in a batch reactor. The model, taking into account the gas–liquid mass transfer, includes hydrogen and five lumps: remaining Residue (>510 °C), VGO (350–510 °C), distillate (180–350 °C), naphtha (40–180 °C), and gas. Vapor–Liquid Equilibrium (VLE) was determined by performing an adiabatic flash with PROII software. Atmospheric Residue fractions reacted with active hydrogen species (activated by dispersed MoS 2 catalysts in-situ generated from a precursor) to give lighter fractions, such as naphtha and gas oil were produced with almost no coke formation. The experiments of atmospheric Residue Hydroconversion were performed under the reaction conditions of 420 or 430 °C, an initial partial pressure of hydrogen of 15 MPa, and different reaction times. Stoichiometric coefficients, kinetic parameters and the mass transfer coefficient (k L a) were estimated using a nonlinear least-squares regression of the experimental results. The calculated apparent activation energies and the contribution of hydrogen concentration via the Hatta number in liquid phase on Hydroconversion were discussed.
Christophe Geantet - One of the best experts on this subject based on the ideXlab platform.
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Improvement of a Kinetic Model for the Hydroconversion of an Atmospheric Residue in a Slurry Semi-batch Reactor
2016Co-Authors: Pedro J. J. Alvarez, Christophe Geantet, Barbara Browning, Jan Maurin, Tim Jansen, Maxime Lacroix, Isabelle Pitault, M. TayakoutAbstract:Previously, using a batch reactor, Nguyen et al. (2013) proposed a kinetic model for atmospheric Residue Hydroconversion wherein Residue consumption rate depends on Residue and dissolved hydrogen concentrations. In the present work, a new kinetic study was carried out in a semi-batch reactor at 420 and 430°C, total pressure of 15 MPa and different reaction times (0, 30, 60 and 120 min). Nguyen’s kinetic model was improved by introducing a hydrodesulfurization (HDS) reaction and modeling the gas flow dynamics at the outlet of the semi-batch reactor. A new set of kinetic parameters for atmospheric Residue Hydroconversion has been estimated using a nonlinear least-squares regression on the total mass of products and the dynamics of outlet gas flow. In comparison to Nguyen’s kinetic study performed in a batch reactor, the results of the present work do not show any mass transfer limitation for H2 from gas to liquid in the semi-batch reactor. A high value of kLa was obtained confirming the high efficiency of this kind of apparatus to estimate the kinetic parameters. Moreover, the differences found between the values of kinetic parameters obtained in both batch and semi-batch reactors were explained by a free radical kinetic model.
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simulation of petroleum Residue Hydroconversion in a continuous pilot unit using batch reactor experiments and a cold mock up
Industrial & Engineering Chemistry Research, 2014Co-Authors: Tim Jansen, Christophe Geantet, Maxime Lacroix, Marie Ropars, Dimitri Guerry, E Leclerc, Melaz TayakoutfayolleAbstract:The kinetics of atmospheric petroleum Residue Hydroconversion with a dispersed catalyst was studied. A methodology has been developed in order to transpose the chemical kinetics (reaction network, stoichiometry, and kinetic constants) obtained with a batch reactor by Nguyen et al. to a continuous reactor [Nguyen, T. S.; Tayakout-Fayolle, M.; Ropars, M.; Geantet, C. Chem. Eng. Sci. 2013, 94, 214]. Their five-lump kinetic model takes into account vapor–liquid mass transfer, vapor–liquid equilibriums, and hydrogen consumption. Consequently, hydrodynamics and vapor–liquid mass transfer of the micropilot unit’s reactor were studied in a cold mock-up by tracer experiments. The same thermodynamic model given by Nguyen et al. was used, and the flash calculations were performed using ProSimPlus software. Experimental data were obtained in the micropilot unit at 420, 430, and 440 °C with a dispersed catalyst for residence times of 1 and 2 h. The catalyst precursor, an oil-soluble molybdenum naphthenate, was added t...
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characterization of a continuous micro scale pilot unit for petroleum Residue Hydroconversion with dispersed catalysts hydrodynamics and performances in once through and recycling mode
Chemical Engineering Journal, 2014Co-Authors: Tim Jansen, Christophe Geantet, Maxime Lacroix, Marie Ropars, Dimitri Guerry, Delphine Gotteland, Robert Bacaud, Chantal Lorentz, Melaz TayakoutfayolleAbstract:Abstract A continuous micro-pilot unit has been designed to convert petroleum Residues with dispersed catalysts. Once-through and recycling modes can be operated. Several operating conditions (residence times and temperatures) have been investigated using the molybdenum naphthenate as catalyst precursor (600 ppm). The micro-pilot hydrodynamics has been characterized via a cold mockup by Residence Time Distribution. Whatever the mode used, the conversion, product yields and average molecular weights depends only on residence time and temperature.
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study of the role of the catalyst and operating conditions on the sediments formation during deep Hydroconversion of vacuum Residue
Applied Catalysis A-general, 2012Co-Authors: Charles Marchal, Denis Uzio, Isabelle Merdrignac, Loic Barre, Christophe GeantetAbstract:Abstract The aim of this work is to investigate the influence of the catalyst and the operating temperature on the sediments formation occurring during vacuum Residue Hydroconversion. At high conversion, instability phenomena occurring due to carbonaceous sediments formation is a tricky issue to address and has detrimental effects on the operability of industrial units. The impact of the catalyst properties on this phenomenon has been scarcely studied. Therefore, a doped F doped NiMo/Al2O3 catalyst has been prepared and catalytic tests performed at two temperature levels (430 and 390 °C) in order to study the effect of catalytic hydrocracking or thermal conversion on the sediment formation. For both temperature regimes, it has been observed that the amount of sediments is strongly reduced with the F-NiMo catalyst compared to the undoped one and attributed to the improvement of the conversion of the sediment precursors (asphaltenes). This improvement is mostly due to the promotion of the acidic and hydrogenation functions by F addition. At 390 °C, coke deposition on F-NiMo catalyst is reduced which limits the plugging of the porous volume and preserve the intragranular diffusion of large molecules in the porosity. It has been shown that deep asphaltenes conversion can be achieved using an improved hydrogenation catalyst by reducing their polarity through the removal of heteroatoms and the saturation of some aromatic rings by hydrogen addition. The residual molecules exhibit lower interactions and self association ability resulting in a lower sediment formation. The temperature has also a great impact on the sediment formation in the effluents since the decrease of the temperature favors hydrogenation and catalytic hydrocracking route which is more appropriated to produce stable effluents compared to radical chemistry predominant at high temperature.
Tim Jansen - One of the best experts on this subject based on the ideXlab platform.
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Kinetic modeling of deep vacuum Residue Hydroconversion in a pilot scale continuous slurry reactor with recycle
Chemical Engineering Journal Advances, 2020Co-Authors: Barbara Browning, Tim Jansen, Maxime Lacroix, Pedro J. J. Alvarez, Françoise Couenne, Mélaz Tayakout-fayolleAbstract:Abstract Slurry phase Hydroconversion is a developing technology with the potential to completely upgrade Vacuum Residues (VR). In this work we use data from a continuous pilot plant with recycle to test and extend an existing distributed lumped kinetic model. The new data includes results from 134 steady state experiments with a Heavy Iran VR, including some at very high conversion, and allows sediment production rates to be quantified as well as sulphur removal in the form of H2S. The purpose of the work is to study the impact of the deep conversion reaction conditions and feedstock on the reaction kinetics. The model uses nineteen distributed lumps to represent the heavy hydrocarbons undergoing Hydroconversion and hydrodesulphurisation with VR defined as the boiling range > 525°C. Reaction rates are based on molar concentrations. Hydrogen consumption and sediment production are taken into account in the model, as well as vapour liquid mass transfer resistances and vapour-liquid equilibrium. Parameter estimation has been carried out and the model provides a good fit with the experimental data. The modelling exercise found that, at very high conversions, thermal reactions give way to a cascade of catalytic reactions. The model gave a moderate fit for hydrogen consumption rates, which are strongly dependent on feedstock. Accumulation of sediment at high conversions was identified and well represented and the description of hydrodesulfurisation rates as proportional to cracking rates was validated.
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Distributed lump kinetic modeling for slurry phase vacuum Residue Hydroconversion
Chemical Engineering Journal, 2019Co-Authors: Barbara Browning, Tim Jansen, Maxime Lacroix, Isabelle Pitault, Françoise Couenne, Pedro Alvarez, Mélaz Tayakout-fayolleAbstract:A detailed distributed lumped kinetic model for slurry phase Vacuum Residue Hydroconversion process (boiling range 525 + °C) has been constructed. Simulated distillation and Gel Permeation Chromatography analysis results were combined to estimate feedstock and product compositions over the whole boiling range. The model uses 21 distributed lumps to represent the hydrocarbons, takes hydrogen consumption into account and calculates reaction rates using molar concentrations. Vapour liquid mass transfer resistances and vapour-liquid equilibrium are also accounted for. The resulting model represents the evolution of the reaction mixture physical properties well and provides a good fit with the experimental data. From estimated parameters, it is deduced that thermally activated and catalytic reactions in cascade occur simultaneously and also that material boiling above 750 °C is converted in a different manner to lighter material.
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Improvement of a Kinetic Model for the Hydroconversion of an Atmospheric Residue in a Slurry Semi-batch Reactor
2016Co-Authors: Pedro J. J. Alvarez, Christophe Geantet, Barbara Browning, Jan Maurin, Tim Jansen, Maxime Lacroix, Isabelle Pitault, M. TayakoutAbstract:Previously, using a batch reactor, Nguyen et al. (2013) proposed a kinetic model for atmospheric Residue Hydroconversion wherein Residue consumption rate depends on Residue and dissolved hydrogen concentrations. In the present work, a new kinetic study was carried out in a semi-batch reactor at 420 and 430°C, total pressure of 15 MPa and different reaction times (0, 30, 60 and 120 min). Nguyen’s kinetic model was improved by introducing a hydrodesulfurization (HDS) reaction and modeling the gas flow dynamics at the outlet of the semi-batch reactor. A new set of kinetic parameters for atmospheric Residue Hydroconversion has been estimated using a nonlinear least-squares regression on the total mass of products and the dynamics of outlet gas flow. In comparison to Nguyen’s kinetic study performed in a batch reactor, the results of the present work do not show any mass transfer limitation for H2 from gas to liquid in the semi-batch reactor. A high value of kLa was obtained confirming the high efficiency of this kind of apparatus to estimate the kinetic parameters. Moreover, the differences found between the values of kinetic parameters obtained in both batch and semi-batch reactors were explained by a free radical kinetic model.
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simulation of petroleum Residue Hydroconversion in a continuous pilot unit using batch reactor experiments and a cold mock up
Industrial & Engineering Chemistry Research, 2014Co-Authors: Tim Jansen, Christophe Geantet, Maxime Lacroix, Marie Ropars, Dimitri Guerry, E Leclerc, Melaz TayakoutfayolleAbstract:The kinetics of atmospheric petroleum Residue Hydroconversion with a dispersed catalyst was studied. A methodology has been developed in order to transpose the chemical kinetics (reaction network, stoichiometry, and kinetic constants) obtained with a batch reactor by Nguyen et al. to a continuous reactor [Nguyen, T. S.; Tayakout-Fayolle, M.; Ropars, M.; Geantet, C. Chem. Eng. Sci. 2013, 94, 214]. Their five-lump kinetic model takes into account vapor–liquid mass transfer, vapor–liquid equilibriums, and hydrogen consumption. Consequently, hydrodynamics and vapor–liquid mass transfer of the micropilot unit’s reactor were studied in a cold mock-up by tracer experiments. The same thermodynamic model given by Nguyen et al. was used, and the flash calculations were performed using ProSimPlus software. Experimental data were obtained in the micropilot unit at 420, 430, and 440 °C with a dispersed catalyst for residence times of 1 and 2 h. The catalyst precursor, an oil-soluble molybdenum naphthenate, was added t...
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characterization of a continuous micro scale pilot unit for petroleum Residue Hydroconversion with dispersed catalysts hydrodynamics and performances in once through and recycling mode
Chemical Engineering Journal, 2014Co-Authors: Tim Jansen, Christophe Geantet, Maxime Lacroix, Marie Ropars, Dimitri Guerry, Delphine Gotteland, Robert Bacaud, Chantal Lorentz, Melaz TayakoutfayolleAbstract:Abstract A continuous micro-pilot unit has been designed to convert petroleum Residues with dispersed catalysts. Once-through and recycling modes can be operated. Several operating conditions (residence times and temperatures) have been investigated using the molybdenum naphthenate as catalyst precursor (600 ppm). The micro-pilot hydrodynamics has been characterized via a cold mockup by Residence Time Distribution. Whatever the mode used, the conversion, product yields and average molecular weights depends only on residence time and temperature.
Kevin J. Smith - One of the best experts on this subject based on the ideXlab platform.
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Catalyst Deactivation in Slurry-Phase Residue Hydroconversion
Energy & Fuels, 2013Co-Authors: Hooman Rezaei, Kevin J. SmithAbstract:MoS2 catalysts used in slurry-phase Hydroconversion of bitumen deactivate when the solid coke–catalyst recovered from the product is recycled in a semi-batch reactor operated at high Residue conversion (445 °C and 13.8 MPa H2). The catalyst deactivation, manifested by an increasing coke yield, is dependent upon the MoS2 concentration in the recycled coke–catalyst and the age of the coke in the reactor. Characterization data show significant changes in the chemical and physical properties of the coke when recycled under Hydroconversion conditions. In particular, with increased recycling, the coke becomes more graphitic with a decreased H/C ratio and an increased aromatic/aliphatic carbon ratio. Model ex situ coke aging experiments, conducted in He at 700 °C for 15 h, were used to confirm that changes in the chemical properties of the recovered coke determined the extent of catalyst deactivation, whereas morphological changes were less important. On the basis of these results, a model of the catalyst deacti...
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study of mos2 catalyst recycle in slurry phase Residue Hydroconversion
Energy & Fuels, 2012Co-Authors: Hooman Rezaei, Shahrzad Jooya Ardakani, Kevin J. SmithAbstract:A study of MoS2 catalyst recycle during slurry-phase Hydroconversion of Residue oil, under high Hydroconversion conditions, is reported. Different concentrations of MoS2 (100, 300, 600, and 1800 ppm Mo derived from Mo-micelle and Mo-octoate precursors) were investigated in a semibatch stirred reactor. Catalyst recycle was simulated by reusing the solid coke-catalyst recovered from the reactor in subsequent experiments. The process was repeated several times until the catalyst deactivated. The recycled catalyst had a very similar activity to the fresh catalyst in the early stages of recycling. Experimental results showed that with increased catalyst concentration, an increased number of catalyst recycles with acceptable coke yield ( 80 wt %) were possible before deactivation was observed. At an initial concentration of 600 ppm Mo (using both Mo-micelle and Mo-octoate precursors), the catalysts were recycled 3 times without any significant lo...
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a study of cold lake vacuum Residue Hydroconversion in batch and semi batch reactors using unsupported mos2 catalysts
Catalysis Today, 2010Co-Authors: Hooman Rezaei, Kevin J. Smith, Shahrzad Jooya Ardakani, Xuebin Liu, Maureen L BrickerAbstract:Abstract Hydroconversion of Cold Lake Vacuum Residue (CLVR) in both batch and semi-batch slurry reactors using unsupported MoS2 catalysts is reported. The MoS2 catalyst precursors were added to the CLVR either as an aqueous solution of ammonium heptamolybdate (AHM) or as molybdenum chloride dispersed in reversed micelles that were stabilized in n-hexane using a surfactant. At the reaction conditions studied in both the batch and semi-batch reactors, the MoS2 catalyst prepared in the reversed micelles had lower coke yield (toluene-insoluble material), lower gas yield, higher liquid yield and higher H2 consumption, compared to the AHM-derived MoS2 catalyst. The coke–catalyst mixture recovered after reaction, characterized by chemical and energy dispersive X-ray analysis, confirmed that most of the added catalyst was captured by the coke. Analysis of the coke by X-ray diffraction and transmission electron microscopy confirmed the presence of highly dispersed MoS2 that suggests the possibility of catalyst–coke recycle.
Hooman Rezaei - One of the best experts on this subject based on the ideXlab platform.
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Catalyst Deactivation in Slurry-Phase Residue Hydroconversion
Energy & Fuels, 2013Co-Authors: Hooman Rezaei, Kevin J. SmithAbstract:MoS2 catalysts used in slurry-phase Hydroconversion of bitumen deactivate when the solid coke–catalyst recovered from the product is recycled in a semi-batch reactor operated at high Residue conversion (445 °C and 13.8 MPa H2). The catalyst deactivation, manifested by an increasing coke yield, is dependent upon the MoS2 concentration in the recycled coke–catalyst and the age of the coke in the reactor. Characterization data show significant changes in the chemical and physical properties of the coke when recycled under Hydroconversion conditions. In particular, with increased recycling, the coke becomes more graphitic with a decreased H/C ratio and an increased aromatic/aliphatic carbon ratio. Model ex situ coke aging experiments, conducted in He at 700 °C for 15 h, were used to confirm that changes in the chemical properties of the recovered coke determined the extent of catalyst deactivation, whereas morphological changes were less important. On the basis of these results, a model of the catalyst deacti...
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study of mos2 catalyst recycle in slurry phase Residue Hydroconversion
Energy & Fuels, 2012Co-Authors: Hooman Rezaei, Shahrzad Jooya Ardakani, Kevin J. SmithAbstract:A study of MoS2 catalyst recycle during slurry-phase Hydroconversion of Residue oil, under high Hydroconversion conditions, is reported. Different concentrations of MoS2 (100, 300, 600, and 1800 ppm Mo derived from Mo-micelle and Mo-octoate precursors) were investigated in a semibatch stirred reactor. Catalyst recycle was simulated by reusing the solid coke-catalyst recovered from the reactor in subsequent experiments. The process was repeated several times until the catalyst deactivated. The recycled catalyst had a very similar activity to the fresh catalyst in the early stages of recycling. Experimental results showed that with increased catalyst concentration, an increased number of catalyst recycles with acceptable coke yield ( 80 wt %) were possible before deactivation was observed. At an initial concentration of 600 ppm Mo (using both Mo-micelle and Mo-octoate precursors), the catalysts were recycled 3 times without any significant lo...
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a study of cold lake vacuum Residue Hydroconversion in batch and semi batch reactors using unsupported mos2 catalysts
Catalysis Today, 2010Co-Authors: Hooman Rezaei, Kevin J. Smith, Shahrzad Jooya Ardakani, Xuebin Liu, Maureen L BrickerAbstract:Abstract Hydroconversion of Cold Lake Vacuum Residue (CLVR) in both batch and semi-batch slurry reactors using unsupported MoS2 catalysts is reported. The MoS2 catalyst precursors were added to the CLVR either as an aqueous solution of ammonium heptamolybdate (AHM) or as molybdenum chloride dispersed in reversed micelles that were stabilized in n-hexane using a surfactant. At the reaction conditions studied in both the batch and semi-batch reactors, the MoS2 catalyst prepared in the reversed micelles had lower coke yield (toluene-insoluble material), lower gas yield, higher liquid yield and higher H2 consumption, compared to the AHM-derived MoS2 catalyst. The coke–catalyst mixture recovered after reaction, characterized by chemical and energy dispersive X-ray analysis, confirmed that most of the added catalyst was captured by the coke. Analysis of the coke by X-ray diffraction and transmission electron microscopy confirmed the presence of highly dispersed MoS2 that suggests the possibility of catalyst–coke recycle.