Modeling SOFC Fueled by Bio-Fuels

In order to determine the performance potential of fuel cells powered by bio-fuels, the resultsobtained were compared with two reference fuels hydrogen and natural gas. Fuel cell characteristics for two reference fuels hydrogen and methane were calculated for a comparative baseline. The type of fuel supplied is not the only 

The use of bio-fuels to feed a fuel cell was tested on an appropriate mathematical model of a singular laboratory cell. This assumption allows the effect of the fuel used to be separated out exclusively and determined independent of other devices which form part of the whole system containing the fuel cell. 

Most of the available experimental data and related results generated by the various models in fact refer to the off-design operation of the fuel cell. Studies which investigate the impact of fuel under off-design operation seek to obtain results in terms of the tolerance of given cells to the new fuel type. To estimate the potential of various fuels for fuel cell feeding, a design point class of models should be used. In those models, the characteristic parameter of the fuel cell is the fuel utilization factor (see Sect. 5.1) instead of the current density. This means that the comparison is made between two cells with the same fuel utilization factor and not the same area. This approach seems more reasonable and could be used to identify the real potential of bio-fuels in fuel cell use. 

With currently built and tested devices, the most widely used material for the electrolyte is YSZ. Therefore this material has been chosen to study bio-fuel fueled SOFC. Achievable levels of fuel utilization factor in cells used commercially reach 80%. Other cell parameters were fixed as follows electrolyte thickness of 15 pm, maximum current density (/max) of 2.6 A/cm, cell working temperature of 800°C, and cell pressure at atmospheric pressure. During the analysis of the oxidant, flow was kept at a constant excess air factor (2) of 3. 

Syngases (canola oil and wood based) and methane, prior to entering the fuel cell, are mixed with steam to obtain a steam to carbon ratio of 1.4. The structure of feeding the fuel cell syngases and methane is shown in Fig. 5.105. 

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