Chapter 16

Explain the fate of the main gas components in biosyngas when the syngas is allowed to pass through the anode of an SOFC producing current.

An electrolyte-supported SOFC is operated at atmospheric pressure and \(800^{\circ} \mathrm{C}\) with the following mole fractions of the reactant and product species: \(x_{\mathrm{H}_{2}}=\) \(0.95\) and \(x_{\mathrm{H}_{2} \mathrm{O}}=0.05\) (anode) and \(x_{\mathrm{O}_{2}}=0.21\) (cathode). At \(800^{\circ} \mathrm{C}\), the fuel cell has \(\Delta \bar{g}_{\mathrm{f}}=-188.6 \mathrm{~kJ} \cdot \mathrm{mol}^{-1}\) and \(\Delta h_{\mathrm{r}}=-248.3 \mathrm{~kJ} \cdot \mathrm{mol}^{-1}\) of \(\mathrm{H}_{2}\), and the conductivity of the cell is \(5 \Omega^{-1} \cdot \mathrm{m}^{-1}\). The cell active area is \(2 \times 10^{-4} \mathrm{~m}^{2}\), and the electrolyte thickness is \(100 \mu \mathrm{m}\). If the cell is operated at \(0.7 \mathrm{~V}\), then determine the following: a. The inlet Nernst voltage b. The rates at which hydrogen and oxygen are consumed c. The electrical efficiency (fuel to electricity)

Compare the electrical and total thermal efficiencies of gasifier-SOFC-GT systems with competing power production technologies.

What are the advantages and disadvantages of high-temperature and nearambient- temperature gas cleaning systems in the context of gasifier-SOFC systems?