Development and validation of a CFD-based steam reformer model

Søren Knudsen Kær, Mathis Dahlqvist, Anders Saksager, Mads Bang, Mads Pagh Nielsen, Anders Korsgaard

Research output: Contribution to book/anthology/report/conference proceedingArticle in proceedingResearchpeer-review

Abstract

Steam reforming of liquid biofuels (ethanol, bio-diesel etc.) represents a sustainable source of hydrogen for micro Combined Heat and Power (CHP) production as well as Auxiliary Power Units (APUs). In relation to the design of the steam reforming reactor several parameter are important including efficiency, start-up time, load following capabilities, and system weight and volume. In order to assist in the development phase of such systems, detailed computational models are useful and offer a potential reduction in the time-to-market as well as lower total development costs due to a reduced need for expensive prototypes. This paper presents an advanced Computational Fluid Dynamics based model of a steam reformer. The model was implemented in the commercial CFD code Fluent through the User Defined Functions interface. The model accounts for the flue gas flow as well as the reformate flow including a detailed mechanism for the reforming reactions. Heat exchange between the flue gas and reformate streams through the reformer reactor walls was also included as a conjugate heat transfer process.  From a review of published models for the catalytic steam reforming of ethanol and preliminary predictions, it was found that ethanol decomposition is not a rate limiting step and can be disregarded without significant error. Model predictions were compared with experimental data in terms of detailed species concentration and temperature profiles inside the reforming reactor. The measurements were made in a commercial ethanol steam reformer. The illustrations below show the measurements locations and predicted and measured temperature profiles. From detailed comparison with the measurements it was concluded that a mechanism for catalytic steam reforming of methane gives a reasonably accurate representation of the ethanol steam reformer.  Based on the model predictions, a detailed investigation of the processes controlling the hydrogen production rates is presented. It was found that efficient heat transfer from the flue gas to the endothermic steam reforming reactions is critical and represents a limiting factor with respect to the reactor dimensions.

Original languageEnglish
Title of host publicationProceedings of the Fuel Cell Seminar 2006 Conference
PublisherFuel Cell Seminar
Publication date2006
Publication statusPublished - 2006
EventFuel Cell Seminar 2006 Conference - Honolulu, Hawaii, United States
Duration: 13 Nov 200617 Nov 2006

Conference

ConferenceFuel Cell Seminar 2006 Conference
CountryUnited States
CityHonolulu, Hawaii
Period13/11/200617/11/2006

Fingerprint

Computational fluid dynamics
Steam reforming
Steam
Ethanol
Reforming reactions
Flue gases
Catalytic reforming
Heat transfer
Biofuels
Hydrogen production
Biodiesel
Flow of gases
Ion exchange
Methane
Decomposition
Hydrogen
Temperature
Liquids
Costs
Hot Temperature

Cite this

Kær, S. K., Dahlqvist, M., Saksager, A., Bang, M., Nielsen, M. P., & Korsgaard, A. (2006). Development and validation of a CFD-based steam reformer model. In Proceedings of the Fuel Cell Seminar 2006 Conference Fuel Cell Seminar.
Kær, Søren Knudsen ; Dahlqvist, Mathis ; Saksager, Anders ; Bang, Mads ; Nielsen, Mads Pagh ; Korsgaard, Anders. / Development and validation of a CFD-based steam reformer model. Proceedings of the Fuel Cell Seminar 2006 Conference. Fuel Cell Seminar, 2006.
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abstract = "Steam reforming of liquid biofuels (ethanol, bio-diesel etc.) represents a sustainable source of hydrogen for micro Combined Heat and Power (CHP) production as well as Auxiliary Power Units (APUs). In relation to the design of the steam reforming reactor several parameter are important including efficiency, start-up time, load following capabilities, and system weight and volume. In order to assist in the development phase of such systems, detailed computational models are useful and offer a potential reduction in the time-to-market as well as lower total development costs due to a reduced need for expensive prototypes. This paper presents an advanced Computational Fluid Dynamics based model of a steam reformer. The model was implemented in the commercial CFD code Fluent through the User Defined Functions interface. The model accounts for the flue gas flow as well as the reformate flow including a detailed mechanism for the reforming reactions. Heat exchange between the flue gas and reformate streams through the reformer reactor walls was also included as a conjugate heat transfer process.  From a review of published models for the catalytic steam reforming of ethanol and preliminary predictions, it was found that ethanol decomposition is not a rate limiting step and can be disregarded without significant error. Model predictions were compared with experimental data in terms of detailed species concentration and temperature profiles inside the reforming reactor. The measurements were made in a commercial ethanol steam reformer. The illustrations below show the measurements locations and predicted and measured temperature profiles. From detailed comparison with the measurements it was concluded that a mechanism for catalytic steam reforming of methane gives a reasonably accurate representation of the ethanol steam reformer.  Based on the model predictions, a detailed investigation of the processes controlling the hydrogen production rates is presented. It was found that efficient heat transfer from the flue gas to the endothermic steam reforming reactions is critical and represents a limiting factor with respect to the reactor dimensions.",
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Kær, SK, Dahlqvist, M, Saksager, A, Bang, M, Nielsen, MP & Korsgaard, A 2006, Development and validation of a CFD-based steam reformer model. in Proceedings of the Fuel Cell Seminar 2006 Conference. Fuel Cell Seminar, Fuel Cell Seminar 2006 Conference, Honolulu, Hawaii, United States, 13/11/2006.

Development and validation of a CFD-based steam reformer model. / Kær, Søren Knudsen; Dahlqvist, Mathis; Saksager, Anders; Bang, Mads; Nielsen, Mads Pagh; Korsgaard, Anders.

Proceedings of the Fuel Cell Seminar 2006 Conference. Fuel Cell Seminar, 2006.

Research output: Contribution to book/anthology/report/conference proceedingArticle in proceedingResearchpeer-review

TY - GEN

T1 - Development and validation of a CFD-based steam reformer model

AU - Kær, Søren Knudsen

AU - Dahlqvist, Mathis

AU - Saksager, Anders

AU - Bang, Mads

AU - Nielsen, Mads Pagh

AU - Korsgaard, Anders

N1 - uddelt på konferencen som cd-rom

PY - 2006

Y1 - 2006

N2 - Steam reforming of liquid biofuels (ethanol, bio-diesel etc.) represents a sustainable source of hydrogen for micro Combined Heat and Power (CHP) production as well as Auxiliary Power Units (APUs). In relation to the design of the steam reforming reactor several parameter are important including efficiency, start-up time, load following capabilities, and system weight and volume. In order to assist in the development phase of such systems, detailed computational models are useful and offer a potential reduction in the time-to-market as well as lower total development costs due to a reduced need for expensive prototypes. This paper presents an advanced Computational Fluid Dynamics based model of a steam reformer. The model was implemented in the commercial CFD code Fluent through the User Defined Functions interface. The model accounts for the flue gas flow as well as the reformate flow including a detailed mechanism for the reforming reactions. Heat exchange between the flue gas and reformate streams through the reformer reactor walls was also included as a conjugate heat transfer process.  From a review of published models for the catalytic steam reforming of ethanol and preliminary predictions, it was found that ethanol decomposition is not a rate limiting step and can be disregarded without significant error. Model predictions were compared with experimental data in terms of detailed species concentration and temperature profiles inside the reforming reactor. The measurements were made in a commercial ethanol steam reformer. The illustrations below show the measurements locations and predicted and measured temperature profiles. From detailed comparison with the measurements it was concluded that a mechanism for catalytic steam reforming of methane gives a reasonably accurate representation of the ethanol steam reformer.  Based on the model predictions, a detailed investigation of the processes controlling the hydrogen production rates is presented. It was found that efficient heat transfer from the flue gas to the endothermic steam reforming reactions is critical and represents a limiting factor with respect to the reactor dimensions.

AB - Steam reforming of liquid biofuels (ethanol, bio-diesel etc.) represents a sustainable source of hydrogen for micro Combined Heat and Power (CHP) production as well as Auxiliary Power Units (APUs). In relation to the design of the steam reforming reactor several parameter are important including efficiency, start-up time, load following capabilities, and system weight and volume. In order to assist in the development phase of such systems, detailed computational models are useful and offer a potential reduction in the time-to-market as well as lower total development costs due to a reduced need for expensive prototypes. This paper presents an advanced Computational Fluid Dynamics based model of a steam reformer. The model was implemented in the commercial CFD code Fluent through the User Defined Functions interface. The model accounts for the flue gas flow as well as the reformate flow including a detailed mechanism for the reforming reactions. Heat exchange between the flue gas and reformate streams through the reformer reactor walls was also included as a conjugate heat transfer process.  From a review of published models for the catalytic steam reforming of ethanol and preliminary predictions, it was found that ethanol decomposition is not a rate limiting step and can be disregarded without significant error. Model predictions were compared with experimental data in terms of detailed species concentration and temperature profiles inside the reforming reactor. The measurements were made in a commercial ethanol steam reformer. The illustrations below show the measurements locations and predicted and measured temperature profiles. From detailed comparison with the measurements it was concluded that a mechanism for catalytic steam reforming of methane gives a reasonably accurate representation of the ethanol steam reformer.  Based on the model predictions, a detailed investigation of the processes controlling the hydrogen production rates is presented. It was found that efficient heat transfer from the flue gas to the endothermic steam reforming reactions is critical and represents a limiting factor with respect to the reactor dimensions.

M3 - Article in proceeding

BT - Proceedings of the Fuel Cell Seminar 2006 Conference

PB - Fuel Cell Seminar

Y2 - 13 November 2006 through 17 November 2006

ER -

Kær SK, Dahlqvist M, Saksager A, Bang M, Nielsen MP, Korsgaard A. Development and validation of a CFD-based steam reformer model. In Proceedings of the Fuel Cell Seminar 2006 Conference. Fuel Cell Seminar. 2006