Investigation of carbon formation on Ni/YSZ anode of solid oxide fuel cell from CO disproportionation reaction

Author(s):  
Dong Hua ◽  
Guojun Li ◽  
Haibin Lu ◽  
Xiongwen Zhang ◽  
Pengfei Fan
Author(s):  
Anthony N. Zinn ◽  
Todd H. Gardner ◽  
David A. Berry ◽  
Robert E. James ◽  
Dushyant Shekhawat

A novel reciprocating compression device has been investigated as a non-catalytic natural gas reformer for solid oxide fuel cell systems. The reciprocating compression reformer is a potential improvement over current reforming technology for select applications due to its high degree of heat integration, its homogenous gas phase reaction environment, and its ability to co-produce shaft work. Performance modeling of the system was conducted to understand component integration and operational characteristics. The reformer was modeled by utilizing GRI mech. in tandem with CHEMKIN. The fuel cell was modeled as an equilibrium reactor assuming constant fuel utilization. The effect on the reformer and the reformer – fuel cell system efficiencies and exit gas concentrations was examined over a range of relative air-to-fuel ratios, 0.2 to 1.0, and at compression ratios of 50 and 100. Results from this study indicate that the reformer – fuel cell system could approach 50% efficiency, if run at low relative air-to-fuel ratios (0.3 to 0.5). With higher air-to-fuel ratios, system efficiencies were shown to continuously decline due to a decrease in the quality of synthesis gas provided to the fuel cell (i.e. more power being produced by the reformer). Optimal operation of the system has been shown to occur at a relative air-to-fuel ratio of approximately 0.775 and to be nearly independent of the compression ratio in the reciprocating compression reformer. Higher efficiencies may be obtained at lower relative air-to-fuel ratios; however, operation below this point may lead to excessive carbon formation as determined from an equilibrium carbon formation analysis.


2020 ◽  
Vol 22 (17) ◽  
pp. 9815-9823
Author(s):  
Martha M. Welander ◽  
Daniel B. Drasbæk ◽  
Marie L. Traulsen ◽  
Bhaskar R. Sudireddy ◽  
Peter Holtappels ◽  
...  

In operando studies of carbon formation on novel niobium doped SrTiO3 based SOFC anodes.


2011 ◽  
Vol 26 (11) ◽  
pp. 1129-1135
Author(s):  
Jian-Guo YU ◽  
Yu-Zhang WANG ◽  
Shi-Lie WENG

RSC Advances ◽  
2012 ◽  
Vol 2 (9) ◽  
pp. 3857 ◽  
Author(s):  
Hongjiao Li ◽  
Ye Tian ◽  
Zhiming Wang ◽  
Fuchang Qie ◽  
Yongdan Li

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 268 ◽  
Author(s):  
Khaliq Ahmed ◽  
Amirpiran Amiri ◽  
Moses O. Tadé

A distributed variable model for solid oxide fuel cell (SOFC), with internal fuel reforming on the anode, has been developed in Aspen HYSYS. The proposed model accounts for the complex and interactive mechanisms involved in the SOFC operation through a mathematically viable and numerically fast modeling framework. The internal fuel reforming reaction calculations have been carried out in a plug flow reactor (PFR) module integrated with a spreadsheet module to interactively calculate the electrochemical process details. By interlinking the two modules within Aspen HYSYS flowsheeting environment, the highly nonlinear SOFC distributed profiles have been readily captured using empirical correlations and without the necessity of using an external coding platform, such as MATLAB or FORTRAN. Distributed variables including temperature, current density, and concentration profiles along the cell length, have been discussed for various reforming activity rates. Moreover, parametric estimation of anode oxidation risk and carbon formation potential against fuel reformation intensity have been demonstrated that contributes to the SOFC lifetime evaluation. Incrementally progressive catalyst activity has been proposed as a technically viable approach for attaining smooth profiles within the SOFC anode. The proposed modeling platform paves the way for SOFC system flowsheeting and optimization, particularly where the study of systems with stack distributed variables is of interest.


Author(s):  
Yongmin Kim ◽  
Jung Hyun Kim ◽  
Gyujong Bae ◽  
Joongmyeon Bae

The change in electrical conductivity of Ni-YSZ cermet used for the solid oxide fuel cell (SOFC) anode was investigated under methane, ethylene and n-butane feeding. Rectangular-shaped pellets have been prepared and exposed to gaseous mixtures including hydrocarbons and nitrogen with or without steam at 750 °C. In the absence of steam, carbon deposition occurred in the Ni-YSZ pellets and consequently the electrical conductivity decreased exponentially. When steam was fed (steam to carbon ratio = 2) to make carbon formation thermodynamically unfavorable, the electrical conductivity was kept constant, except for supplying butane. The effect of the mole fraction of methane on the change of electrical conductivity was also investigated in the CH4-N2 system. When the molar concentration was increased, the rate of decrease of electrical conductivity was increased. The present study helps to understand the effect of carbon deposition on the electrical conductivity of Ni-YSZ anode.


Author(s):  
J. Lin ◽  
M. R. Walluk ◽  
D. F. Smith ◽  
T. A. Trabold

Biodiesel is considered as a renewable hydrogen source for solid oxide fuel cells (SOFCs). This study contributes to a fundamental understanding of biodiesel auto-thermal reforming (ATR), which has not yet been widely explored in the open literature. Ultra-lower sulfur diesel (ULSD) ATR is established as a baseline for this analysis. Solid carbon formation during AT R has been recognized as a primary degradation mode in solid oxide fuel cell-based auxiliary power unit systems in transportation applications, but is difficult to detect and control. To overcome these challenges, this work applies a direct photo-acoustic method to analyze carbon dynamic evolutions and quantify the carbon formation in a single-tube reformer under various operating conditions (temperature, steam/carbon ratio, and oxygen/carbon ratio). The key objective is to locate the optimum operating environment for biodiesel ATR with carbon-free deposition and peak hydrogen yield. Thermodynamic analysis based on the method of total Gibbs free energy minimization is used to evaluate the equilibrium reformate compositions. The experimental investigations complimented with the theoretical analysis of biodiesel ATR helps effectively optimize the onboard reforming conditions.


2019 ◽  
Vol 123 (18) ◽  
pp. 11406-11413
Author(s):  
Martha M. Welander ◽  
Marley S. Zachariasen ◽  
Stephen W. Sofie ◽  
Robert A. Walker

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