Kinetic Analysis of $C4$ Alkane and Alkene Pyrolysis: Implications for SOFC Operation

Pyrolysis experiments of isobutane, isobutylene, and 1-butene were performed over a temperature range of $550–750°C$ and a pressure of $∼0.8atm$⁠. The residence time was $∼5s$⁠. The fuel conversion and product selectivity were analyzed at these temperatures. The pyrolysis experiments were performed to simulate the gas-phase chemistry that occurs in the anode channel of a solid-oxide fuel cell (SOFC). The experimental results confirm that molecular structure has a substantial impact on pyrolysis kinetics. The experimental data show considerable amounts of $C5$ and higher species (⁠$∼2.8mole%$ with isobutane at $750°C$⁠, $∼7.5mole%$ with isobutylene at $737.5°C$⁠, and $∼7.4mole%$ with 1-butene at $700°C$⁠). The $C5+$ species are likely deposit precursors. The results confirm that hydrocarbon gas-phase kinetics have substantial impact on a SOFC operation.