Numerical analysis of an internal methane reforming solid oxide fuel cell with fuel recycling
The development of solid oxide fuel cell (SOFC) systems capable of direct internal reforming (DIR) of methane is being actively pursued. However, a major challenge with current state-of-the-art nickel-based anodes is their propensity to form deteriorous carbon deposits in DIR, unless excess steam is introduced in the fuel. Reduced fuel humidification levels are desirable from the viewpoints of cell performance, reliability and plant economics. This study explores the use of partial recycling of the anode exhaust as a mitigation strategy against carbon deposits at fuel steam-to-carbon ratios less than unity. Using a detailed computational fluid dynamics (CFD) model which couples momentum, heat, mass and charge transport with electrochemical and chemical reactions, the spatial extent of carbon deposition within a SOFC anode is analyzed by accounting for both the cracking and Boudouard reactions, for several fuel humidification and recycling conditions. At temperatures of approximately 1173K and for inlet fuel molar H2O/CH4 ratios between 0.5 and 1, 50% (mass%) fuel recycling is found to be an effective strategy against carbon deposition. For lower recycling levels at the same fuel compositions, or lower fuel humidification levels (regardless of the recycling level), fuel recycling reduces the risk of coking, but does not eliminate it. The analyses presented suggest that recycling of the anodic fuel stream could help extend the operational range of DIR-SOFCs to lower fuel humidification levels than typically considered, with reduced risks of carbon deposits, while reducing system cost and complexity in terms of steam production. For dry or weakly humidified fuels, additional mitigation strategies would be required.
If you experience problems downloading a file, check if you have the proper application to view it first. In case of further problems read the IDEAS help page. Note that these files are not on the IDEAS site. Please be patient as the files may be large.
As the access to this document is restricted, you may want to look for a different version under "Related research" (further below) or search for a different version of it.
Volume (Year): 93 (2012)
Issue (Month): C ()
|Contact details of provider:|| Web page: http://www.elsevier.com/wps/find/journaldescription.cws_home/405891/description#description|
|Order Information:|| Postal: http://www.elsevier.com/wps/find/journaldescription.cws_home/405891/bibliographic|
When requesting a correction, please mention this item's handle: RePEc:eee:appene:v:93:y:2012:i:c:p:107-115. See general information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Zhang, Lei)
If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.
If references are entirely missing, you can add them using this form.
If the full references list an item that is present in RePEc, but the system did not link to it, you can help with this form.
If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your profile, as there may be some citations waiting for confirmation.
Please note that corrections may take a couple of weeks to filter through the various RePEc services.