Tony Bridgwater | Aston University (original) (raw)
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Papers by Tony Bridgwater
Applied Geochemistry, 2017
Molecular Catalysis, 2021
Bioresource Technology, Feb 1, 2011
Energy & Fuels, Feb 22, 2010
ABSTRACT The paper presents a comparison between the different drag models for granular flows dev... more ABSTRACT The paper presents a comparison between the different drag models for granular flows developed in the literature and the effect of each one of them on the fast pyrolysis of wood. The process takes place on an 100 g/h lab scale bubbling fluidized bed reactor located at Aston University. FLUENT 6.3 is used as the modeling framework of the fluidized bed hydrodynamics, while the fast pyrolysis of the discrete wood particles is incorporated as an external user defined function (UDF) hooked to FLUENT’s main code structure. Three different drag models for granular flows are compared, namely the Gidaspow, Syamlal O’Brien, and Wen-Yu, already incorporated in FLUENT’s main code, and their impact on particle trajectory, heat transfer, degradation rate, product yields, and char residence time is quantified. The Eulerian approach is used to model the bubbling behavior of the sand, which is treated as a continuum. Biomass reaction kinetics is modeled according to the literature using a two-stage, semiglobal model that takes into account secondary reactions.
Applied Energy, Jun 1, 2022
Applied Catalysis A-general, Sep 1, 2019
Environmental progress & sustainable energy, Apr 5, 2012
A systematic survey of the possible methods of chemical extraction of iron by chloride formation ... more A systematic survey of the possible methods of chemical extraction of iron by chloride formation has been presented and supported by a comparable study of :feedstocks, products and markets. The generation and evaluation of alternative processes was carried out by the technique of morphological analysis vihich was exploited by way of a computer program. The final choice was related to technical feasibility and economic viability, particularly capital cost requirements and developments were made in an estimating procedure for hydrometallurgjcal processes which have general applications. The systematic exploration included the compilation of relevant data, and this indicated a need.to investigate precipitative hydrolysis or aqueous ferric chloride. Arising from this study, two novel hydrometallurgical processes for manufacturing iron powder are proposed and experimental work was undertaken in the following .areas to demonstrate feasibility and obtain basic data for design purposes: (1)...
This paper presents the main results of the French project PRECOND which aimed at evaluating the ... more This paper presents the main results of the French project PRECOND which aimed at evaluating the technical & economical viability of fast pyrolysis as biomass preconditioning route for the following utilizations: gasification and FT-synthesis into synthetic transport bio-fuels; petroleum co-refining into transport bio-fuels; combustion for CHP. First, the expected bio-oil specifications have been assessed according to the utilization. A bench scale fluidized bed, identified as the reference technology, was constructed and operated on different biomasses. The methods for physico-chemical characterization of bio-oils were characterized were evaluated, as well as their stability and rheological behaviour. Besides, a new model of the reactor was set-up, resulting in good predictions of the experimental mass balances. Finally, a techno-economical assessment of the whole preconditioning route has led to evaluation of bio-oil production costs and the consequence on the utilizations consid...
Perennial grasses offer potential for providing a year round supply of low cost biomass when grow... more Perennial grasses offer potential for providing a year round supply of low cost biomass when grown in southern European conditions. Four crops, Giant reed, Cardoon thistle, Miscanthus and Switchgrass have been assessed for ash content, composition and melting behaviour. Ash content for all four crops is high compared to wood and initial data suggests soil contamination is a major contributor. All crops have naturally high levels of potassium and chlorine but it is notable that Cardoon also has high levels of calcium and sodium. Ash melting temperatures are between 1000°C and 1160°C in oxidizing conditions except for Cardoon where some samples have sintered at ca 750°C. Pilot scale combustion tests on Giant reed, Miscanthus and Switchgrass at Graz showed slag accumulation on the grate, high rates of fouling and high emissions. Corrosion problems would also be expected. Preliminary fluidized bed gasification of Switchgrass was successful, however testing on Cardoon was abandoned due t...
Waste and Biomass Valorization, 2020
This study aims to compare the potential of Virginia mallow to other high yielding perennial gras... more This study aims to compare the potential of Virginia mallow to other high yielding perennial grasses and hardwoods by characterising and comparing fast pyrolysis product yields. Feedstocks selected for this study include miscanthus (Miscanthus x giganteus), Virginia mallow (Sida hermaphrodita), willow short rotation coppice (SRC) (Salix viminalis) and oak (Quercus robur). The experimental work was split into two sections: analytical (Py–GC–MS) and laboratory-scale processing using a 300 g h−1 continuous bubbling fluidised bed reactor. Pyrolysis–gas chromatography–mass spectrometry (Py–GC–MS) has been used to quantify pyrolysis products from these feedstocks by simulating fast pyrolysis heating rates using a CDS 5200 pyrolyser closed coupled to a PerkinElmer Clarus 680 GC–MS. High bio-oil yields were achieved for Virginia mallow, willow SRC and oak (65.36, 62.55 and 66.43 wt% respectively), but miscanthus only produced a yield of 53.46 wt% due to increased feedstock ash content. The ...
Journal of Analytical and Applied Pyrolysis, 2018
Fuel Processing Technology, 2018
Applied Geochemistry, 2017
Molecular Catalysis, 2021
Bioresource Technology, Feb 1, 2011
Energy & Fuels, Feb 22, 2010
ABSTRACT The paper presents a comparison between the different drag models for granular flows dev... more ABSTRACT The paper presents a comparison between the different drag models for granular flows developed in the literature and the effect of each one of them on the fast pyrolysis of wood. The process takes place on an 100 g/h lab scale bubbling fluidized bed reactor located at Aston University. FLUENT 6.3 is used as the modeling framework of the fluidized bed hydrodynamics, while the fast pyrolysis of the discrete wood particles is incorporated as an external user defined function (UDF) hooked to FLUENT’s main code structure. Three different drag models for granular flows are compared, namely the Gidaspow, Syamlal O’Brien, and Wen-Yu, already incorporated in FLUENT’s main code, and their impact on particle trajectory, heat transfer, degradation rate, product yields, and char residence time is quantified. The Eulerian approach is used to model the bubbling behavior of the sand, which is treated as a continuum. Biomass reaction kinetics is modeled according to the literature using a two-stage, semiglobal model that takes into account secondary reactions.
Applied Energy, Jun 1, 2022
Applied Catalysis A-general, Sep 1, 2019
Environmental progress & sustainable energy, Apr 5, 2012
A systematic survey of the possible methods of chemical extraction of iron by chloride formation ... more A systematic survey of the possible methods of chemical extraction of iron by chloride formation has been presented and supported by a comparable study of :feedstocks, products and markets. The generation and evaluation of alternative processes was carried out by the technique of morphological analysis vihich was exploited by way of a computer program. The final choice was related to technical feasibility and economic viability, particularly capital cost requirements and developments were made in an estimating procedure for hydrometallurgjcal processes which have general applications. The systematic exploration included the compilation of relevant data, and this indicated a need.to investigate precipitative hydrolysis or aqueous ferric chloride. Arising from this study, two novel hydrometallurgical processes for manufacturing iron powder are proposed and experimental work was undertaken in the following .areas to demonstrate feasibility and obtain basic data for design purposes: (1)...
This paper presents the main results of the French project PRECOND which aimed at evaluating the ... more This paper presents the main results of the French project PRECOND which aimed at evaluating the technical & economical viability of fast pyrolysis as biomass preconditioning route for the following utilizations: gasification and FT-synthesis into synthetic transport bio-fuels; petroleum co-refining into transport bio-fuels; combustion for CHP. First, the expected bio-oil specifications have been assessed according to the utilization. A bench scale fluidized bed, identified as the reference technology, was constructed and operated on different biomasses. The methods for physico-chemical characterization of bio-oils were characterized were evaluated, as well as their stability and rheological behaviour. Besides, a new model of the reactor was set-up, resulting in good predictions of the experimental mass balances. Finally, a techno-economical assessment of the whole preconditioning route has led to evaluation of bio-oil production costs and the consequence on the utilizations consid...
Perennial grasses offer potential for providing a year round supply of low cost biomass when grow... more Perennial grasses offer potential for providing a year round supply of low cost biomass when grown in southern European conditions. Four crops, Giant reed, Cardoon thistle, Miscanthus and Switchgrass have been assessed for ash content, composition and melting behaviour. Ash content for all four crops is high compared to wood and initial data suggests soil contamination is a major contributor. All crops have naturally high levels of potassium and chlorine but it is notable that Cardoon also has high levels of calcium and sodium. Ash melting temperatures are between 1000°C and 1160°C in oxidizing conditions except for Cardoon where some samples have sintered at ca 750°C. Pilot scale combustion tests on Giant reed, Miscanthus and Switchgrass at Graz showed slag accumulation on the grate, high rates of fouling and high emissions. Corrosion problems would also be expected. Preliminary fluidized bed gasification of Switchgrass was successful, however testing on Cardoon was abandoned due t...
Waste and Biomass Valorization, 2020
This study aims to compare the potential of Virginia mallow to other high yielding perennial gras... more This study aims to compare the potential of Virginia mallow to other high yielding perennial grasses and hardwoods by characterising and comparing fast pyrolysis product yields. Feedstocks selected for this study include miscanthus (Miscanthus x giganteus), Virginia mallow (Sida hermaphrodita), willow short rotation coppice (SRC) (Salix viminalis) and oak (Quercus robur). The experimental work was split into two sections: analytical (Py–GC–MS) and laboratory-scale processing using a 300 g h−1 continuous bubbling fluidised bed reactor. Pyrolysis–gas chromatography–mass spectrometry (Py–GC–MS) has been used to quantify pyrolysis products from these feedstocks by simulating fast pyrolysis heating rates using a CDS 5200 pyrolyser closed coupled to a PerkinElmer Clarus 680 GC–MS. High bio-oil yields were achieved for Virginia mallow, willow SRC and oak (65.36, 62.55 and 66.43 wt% respectively), but miscanthus only produced a yield of 53.46 wt% due to increased feedstock ash content. The ...
Journal of Analytical and Applied Pyrolysis, 2018
Fuel Processing Technology, 2018