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 ̃0.8 atm. The residence time was ̃5 s. 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 C ₅ and higher species (̃2.8 mole % with isobutane at 750°C, ̃7.5 mole % with isobutylene at 737.5°C, and ̃7.4 mole % with 1-butene at 700°C). The C ₅+ species are likely deposit precursors. The results confirm that hydrocarbon gas-phase kinetics have substantial impact on a SOFC operation.