behdad moghtaderi - Academia.edu (original) (raw)

Papers by behdad moghtaderi

Energy & Fuels, Jan 6, 2015

ABSTRACT Fe2O3/Al2O3 is found to be a suitable oxygen carrier candidate for the chemical looping ... more ABSTRACT Fe2O3/Al2O3 is found to be a suitable oxygen carrier candidate for the chemical looping combustion with ultra-low methane concentration in a previous study by our team. In order to facilitate the fundamental reactor design and understand the energy consumption, the reduction kinetics mechanism of Fe2O3 (hematite) with 0.5 vol% CH4 was determined and the kinetic parameters were estimated based on the thermogravimetric analysis. Two oxygen carriers (i.e. Fe25Al and Fe45Al) were prepared and used in the TGA experiment. It was observed that the reduction of Fe2O3 was a two-steps process. Initially Fe2O3 is transformed into Fe3O4 (magnetite) at a fast reaction rate and followed by a slow step corresponding to the reduction from Fe3O4 to FeAl2O4. A topochemical approach associated with Hancock and Sharp’s method was therefore applied to determine the most suitable kinetic model for the reduction process. It was found that the initial fast step can be described by Avrami-Erofe’ev phase change model, A2 model for low conversion and A3 model for high conversion, whereas the reaction for the second step was in diffusion control. It also can be concluded that within the Fe2O3 content of 25-45 wt%, there is no difference on the reduction kinetic mechanism and similar activation energy was obtained which can be comparable with the findings in the literature.

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Energy & Fuels, Feb 27, 2015

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Energy Conversion and Management, Sep 1, 2014

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Energy & Fuels, May 5, 2016

A dual-loop chemical looping process is proposed to produce hydrogen from ventilation air methane... more A dual-loop chemical looping process is proposed to produce hydrogen from ventilation air methane (VAM). It mainly consists of two loops, an oxygen removal loop and a hydrogen production loop. The oxygen removal loop is a Cu-based chemical looping air separation process, in which the oxygen content is separated through the reversible reaction 4CuO ⇄ 2Cu2O + O2 + 263.2 kJ/mol.The oxygen-depleted stream is subsequently fed into the hydrogen production loop, where the ultra-low-concentration methane is reformed into highly pure hydrogen. In light of the thermodynamics and experimental results, the oxygen removal temperature should be in the range of 300–400 °C in order to commence the oxidation of Cu2O at a proper kinetics rate while the catalytic combustion of VAM and reduction of copper oxides with methane are inhibited. Two configurations are proposed, and the thermodynamic performance is evaluated by a case study with methane concentration of 0.5 vol%. It was found that the proposed system was able to pr...

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International Journal of Hydrogen Energy, Oct 1, 2012

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Combustion Science and Technology, 2019

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Energy & Fuels, 2019

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Combustion Science and Technology, 2019

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The Canadian Journal of Chemical Engineering, 2018

A heterogeneous nucleation model with inclusions of the line tension effect, the particle roughne... more A heterogeneous nucleation model with inclusions of the line tension effect, the particle roughness effect, and the surface diffusion mechanism was presented. Effects of the particle roughness and the wetting agent on the heterogeneous nucleation behaviour were examined. The scaled nucleation barrier was analyzed and subsequently implications of the nucleation behaviour in the particulate abatement by vapour condensation were discussed. It was found that the effect of particle roughness on the nucleation behaviour was greatly affected by the line tension. There existed an optimal concentration of wetting agent at which the lowest nucleation barrier and critical saturation ratio could be obtained. The surface diffusion mechanism played an overwhelmingly important role in governing the embryo growth for hydrophilic particles with a diameter Dp > 0.1 µm and an embryo size smaller than the critical size, otherwise the contribution of direct vapour deposition mechanism could be signif...

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Industrial & Engineering Chemistry Research, 2016

Ferrofluids are a unique class of colloidal liquids made of ferromagnetic or ferrimagnetic nanopa... more Ferrofluids are a unique class of colloidal liquids made of ferromagnetic or ferrimagnetic nanoparticles suspended in a carrier fluid. Ferrofluids have drawn considerable attention due to the possibility of tuning their heat transfer and flow properties through the application of an external magnetic field. They can also be utilized to improve the performance of an energy harvester, which can supply power and enhance the capability, assertion and lifespan of those devices where batteries or direct electricity are currently used as the primary source of power. Electromagnetic ferrofluid based energy harvesters convert the ferrofluids sloshing movement into electromotive force; therefore, it is necessary to estimate the feasibility, stability and efficacy of ferrofluids through several physicochemical studies. The objective of this work is to prepare a stable polymer coated Fe3O4 nanofluid with the aim of applying it in a novel energy harvester device currently under development at the University of Newcast...

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Energy & Fuels, 2017

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Energy & Fuels, 2015

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Energy & Fuels, 2015

ABSTRACT Fe2O3/Al2O3 is found to be a suitable oxygen carrier candidate for the chemical looping ... more ABSTRACT Fe2O3/Al2O3 is found to be a suitable oxygen carrier candidate for the chemical looping combustion with ultra-low methane concentration in a previous study by our team. In order to facilitate the fundamental reactor design and understand the energy consumption, the reduction kinetics mechanism of Fe2O3 (hematite) with 0.5 vol% CH4 was determined and the kinetic parameters were estimated based on the thermogravimetric analysis. Two oxygen carriers (i.e. Fe25Al and Fe45Al) were prepared and used in the TGA experiment. It was observed that the reduction of Fe2O3 was a two-steps process. Initially Fe2O3 is transformed into Fe3O4 (magnetite) at a fast reaction rate and followed by a slow step corresponding to the reduction from Fe3O4 to FeAl2O4. A topochemical approach associated with Hancock and Sharp’s method was therefore applied to determine the most suitable kinetic model for the reduction process. It was found that the initial fast step can be described by Avrami-Erofe’ev phase change model, A2 model for low conversion and A3 model for high conversion, whereas the reaction for the second step was in diffusion control. It also can be concluded that within the Fe2O3 content of 25-45 wt%, there is no difference on the reduction kinetic mechanism and similar activation energy was obtained which can be comparable with the findings in the literature.

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Journal of Applied Fire Science, 1996

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International Journal of Hydrogen Energy, 2012

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Energy Conversion and Management, 2014

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Energy & Fuels, 2011

ABSTRACT A novel integrated gasification chemical looping combustion (IGCLC) process is proposed ... more ABSTRACT A novel integrated gasification chemical looping combustion (IGCLC) process is proposed here for combustion of solid fuels, particularly coal. The proposed process incorporates an ex situ step for gasification of the solid fuel, but unlike conventional ex situ methods, the gasification process is fully integrated with the combustion process. This is achieved using a three-step chemical loop for the production of hydrogen, combustion of gaseous fuels, and regeneration of metal oxides. A detailed thermodynamic chemical equilibrium assessment of the IGCLC process was carried out to evaluate its technical viability. The relevant analyses were performed using Aspen Plus process simulation software. The IGCLC process was found to be thermodynamically feasible. More specifically, it was uncovered that the gasification process can operate at an adequate temperature (above 1023 K) at thermoneutral conditions with high coal conversion (95%). It was also found that, to achieve the highest hydrogen production, the steam/hydrogen to carbon ratio (SHTCR) had to be set to 2, at which the gasification temperature was around 1070 K, coal conversion was 95%, gaseous fuel reactor (i.e., combustor) temperature was 1140 K, and H2 productivity was 0.85 mol/mol carbon. Mass and energy balance calculations were also performed. It demonstrated that the proposed IGCLC system can achieve an electricity efficiency of 49.5% at SHTCR 2 and feed temperature of 1100 K with some appropriate assumptions, which is 80% higher than a conventional coal-fired power station with carbon capture and storage (CCS) measures.

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Applied Energy, 2014

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Fire Safety Science, 2001

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Sustainability

There is a trend towards harvesting tidal energy in shallow water. This study examined how tidal ... more There is a trend towards harvesting tidal energy in shallow water. This study examined how tidal energy can be harvested using a device of oscillating cylinders inspired by the roots of mangroves. A specific focus was placed on optimising the configuration of these devices, informed by the computational fluid dynamics (CFD) analysis of wake interference in the von Kármán vortex street of the cylinders. A maximum efficiency of 13.54% was achieved at a peak voltage of 16 mV, corresponding to an electrical power output of 0.0199 mW (13.5% of the hydrokinetic energy of the water) and a power density of 7.2 mW/m2 for a flow velocity of 0.04 m/s (Re=239). The configuration of upstream cylinders proved to have a significant impact on the power generation capacity, corroborated further in CFD simulations. The effect of wake interference was non-trivial on the magnitude and quality of power, with tandem arrangements showing the largest impact followed by staggered arrangements. Though with c...

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Energy & Fuels, Jan 6, 2015

ABSTRACT Fe2O3/Al2O3 is found to be a suitable oxygen carrier candidate for the chemical looping ... more ABSTRACT Fe2O3/Al2O3 is found to be a suitable oxygen carrier candidate for the chemical looping combustion with ultra-low methane concentration in a previous study by our team. In order to facilitate the fundamental reactor design and understand the energy consumption, the reduction kinetics mechanism of Fe2O3 (hematite) with 0.5 vol% CH4 was determined and the kinetic parameters were estimated based on the thermogravimetric analysis. Two oxygen carriers (i.e. Fe25Al and Fe45Al) were prepared and used in the TGA experiment. It was observed that the reduction of Fe2O3 was a two-steps process. Initially Fe2O3 is transformed into Fe3O4 (magnetite) at a fast reaction rate and followed by a slow step corresponding to the reduction from Fe3O4 to FeAl2O4. A topochemical approach associated with Hancock and Sharp’s method was therefore applied to determine the most suitable kinetic model for the reduction process. It was found that the initial fast step can be described by Avrami-Erofe’ev phase change model, A2 model for low conversion and A3 model for high conversion, whereas the reaction for the second step was in diffusion control. It also can be concluded that within the Fe2O3 content of 25-45 wt%, there is no difference on the reduction kinetic mechanism and similar activation energy was obtained which can be comparable with the findings in the literature.

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Energy & Fuels, Feb 27, 2015

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Energy Conversion and Management, Sep 1, 2014

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Energy & Fuels, May 5, 2016

A dual-loop chemical looping process is proposed to produce hydrogen from ventilation air methane... more A dual-loop chemical looping process is proposed to produce hydrogen from ventilation air methane (VAM). It mainly consists of two loops, an oxygen removal loop and a hydrogen production loop. The oxygen removal loop is a Cu-based chemical looping air separation process, in which the oxygen content is separated through the reversible reaction 4CuO ⇄ 2Cu2O + O2 + 263.2 kJ/mol.The oxygen-depleted stream is subsequently fed into the hydrogen production loop, where the ultra-low-concentration methane is reformed into highly pure hydrogen. In light of the thermodynamics and experimental results, the oxygen removal temperature should be in the range of 300–400 °C in order to commence the oxidation of Cu2O at a proper kinetics rate while the catalytic combustion of VAM and reduction of copper oxides with methane are inhibited. Two configurations are proposed, and the thermodynamic performance is evaluated by a case study with methane concentration of 0.5 vol%. It was found that the proposed system was able to pr...

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International Journal of Hydrogen Energy, Oct 1, 2012

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Combustion Science and Technology, 2019

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Energy & Fuels, 2019

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Combustion Science and Technology, 2019

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The Canadian Journal of Chemical Engineering, 2018

A heterogeneous nucleation model with inclusions of the line tension effect, the particle roughne... more A heterogeneous nucleation model with inclusions of the line tension effect, the particle roughness effect, and the surface diffusion mechanism was presented. Effects of the particle roughness and the wetting agent on the heterogeneous nucleation behaviour were examined. The scaled nucleation barrier was analyzed and subsequently implications of the nucleation behaviour in the particulate abatement by vapour condensation were discussed. It was found that the effect of particle roughness on the nucleation behaviour was greatly affected by the line tension. There existed an optimal concentration of wetting agent at which the lowest nucleation barrier and critical saturation ratio could be obtained. The surface diffusion mechanism played an overwhelmingly important role in governing the embryo growth for hydrophilic particles with a diameter Dp > 0.1 µm and an embryo size smaller than the critical size, otherwise the contribution of direct vapour deposition mechanism could be signif...

Bookmarks Related papers MentionsView impact

Industrial & Engineering Chemistry Research, 2016

Ferrofluids are a unique class of colloidal liquids made of ferromagnetic or ferrimagnetic nanopa... more Ferrofluids are a unique class of colloidal liquids made of ferromagnetic or ferrimagnetic nanoparticles suspended in a carrier fluid. Ferrofluids have drawn considerable attention due to the possibility of tuning their heat transfer and flow properties through the application of an external magnetic field. They can also be utilized to improve the performance of an energy harvester, which can supply power and enhance the capability, assertion and lifespan of those devices where batteries or direct electricity are currently used as the primary source of power. Electromagnetic ferrofluid based energy harvesters convert the ferrofluids sloshing movement into electromotive force; therefore, it is necessary to estimate the feasibility, stability and efficacy of ferrofluids through several physicochemical studies. The objective of this work is to prepare a stable polymer coated Fe3O4 nanofluid with the aim of applying it in a novel energy harvester device currently under development at the University of Newcast...

Bookmarks Related papers MentionsView impact

Energy & Fuels, 2017

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Energy & Fuels, 2015

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Energy & Fuels, 2015

ABSTRACT Fe2O3/Al2O3 is found to be a suitable oxygen carrier candidate for the chemical looping ... more ABSTRACT Fe2O3/Al2O3 is found to be a suitable oxygen carrier candidate for the chemical looping combustion with ultra-low methane concentration in a previous study by our team. In order to facilitate the fundamental reactor design and understand the energy consumption, the reduction kinetics mechanism of Fe2O3 (hematite) with 0.5 vol% CH4 was determined and the kinetic parameters were estimated based on the thermogravimetric analysis. Two oxygen carriers (i.e. Fe25Al and Fe45Al) were prepared and used in the TGA experiment. It was observed that the reduction of Fe2O3 was a two-steps process. Initially Fe2O3 is transformed into Fe3O4 (magnetite) at a fast reaction rate and followed by a slow step corresponding to the reduction from Fe3O4 to FeAl2O4. A topochemical approach associated with Hancock and Sharp’s method was therefore applied to determine the most suitable kinetic model for the reduction process. It was found that the initial fast step can be described by Avrami-Erofe’ev phase change model, A2 model for low conversion and A3 model for high conversion, whereas the reaction for the second step was in diffusion control. It also can be concluded that within the Fe2O3 content of 25-45 wt%, there is no difference on the reduction kinetic mechanism and similar activation energy was obtained which can be comparable with the findings in the literature.

Bookmarks Related papers MentionsView impact

Journal of Applied Fire Science, 1996

Bookmarks Related papers MentionsView impact

International Journal of Hydrogen Energy, 2012

Bookmarks Related papers MentionsView impact

Energy Conversion and Management, 2014

Bookmarks Related papers MentionsView impact

Energy & Fuels, 2011

ABSTRACT A novel integrated gasification chemical looping combustion (IGCLC) process is proposed ... more ABSTRACT A novel integrated gasification chemical looping combustion (IGCLC) process is proposed here for combustion of solid fuels, particularly coal. The proposed process incorporates an ex situ step for gasification of the solid fuel, but unlike conventional ex situ methods, the gasification process is fully integrated with the combustion process. This is achieved using a three-step chemical loop for the production of hydrogen, combustion of gaseous fuels, and regeneration of metal oxides. A detailed thermodynamic chemical equilibrium assessment of the IGCLC process was carried out to evaluate its technical viability. The relevant analyses were performed using Aspen Plus process simulation software. The IGCLC process was found to be thermodynamically feasible. More specifically, it was uncovered that the gasification process can operate at an adequate temperature (above 1023 K) at thermoneutral conditions with high coal conversion (95%). It was also found that, to achieve the highest hydrogen production, the steam/hydrogen to carbon ratio (SHTCR) had to be set to 2, at which the gasification temperature was around 1070 K, coal conversion was 95%, gaseous fuel reactor (i.e., combustor) temperature was 1140 K, and H2 productivity was 0.85 mol/mol carbon. Mass and energy balance calculations were also performed. It demonstrated that the proposed IGCLC system can achieve an electricity efficiency of 49.5% at SHTCR 2 and feed temperature of 1100 K with some appropriate assumptions, which is 80% higher than a conventional coal-fired power station with carbon capture and storage (CCS) measures.

Bookmarks Related papers MentionsView impact

Applied Energy, 2014

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Fire Safety Science, 2001

Bookmarks Related papers MentionsView impact

Sustainability

There is a trend towards harvesting tidal energy in shallow water. This study examined how tidal ... more There is a trend towards harvesting tidal energy in shallow water. This study examined how tidal energy can be harvested using a device of oscillating cylinders inspired by the roots of mangroves. A specific focus was placed on optimising the configuration of these devices, informed by the computational fluid dynamics (CFD) analysis of wake interference in the von Kármán vortex street of the cylinders. A maximum efficiency of 13.54% was achieved at a peak voltage of 16 mV, corresponding to an electrical power output of 0.0199 mW (13.5% of the hydrokinetic energy of the water) and a power density of 7.2 mW/m2 for a flow velocity of 0.04 m/s (Re=239). The configuration of upstream cylinders proved to have a significant impact on the power generation capacity, corroborated further in CFD simulations. The effect of wake interference was non-trivial on the magnitude and quality of power, with tandem arrangements showing the largest impact followed by staggered arrangements. Though with c...

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