Impact of low concentration hydrocarbons in natural gas on thermal partial oxidation in a micro-flow reactor for solid oxide fuel cell applications

The increase in production and decrease in cost of natural gas have made it a viable alternative fuel to petroleum and coal power-based systems. The thermal partial oxidation of natural gas has been investigated previously, but few have investigated the effects of lower concentration hydrocarbons on reforming characteristics; especially at low temperatures (<1000 °C). This study investigates the microcombustion reforming of methane/air and natural gas/air utilizing heat recirculation to achieve high synthesis gas production. Maximum wall temperatures of 800–1000 °C at total flow rates of 10 and 50 mL min⁻¹ are investigated. Equivalence ratios 1–5 are investigated with no soot formation present in the reactor at 800 °C and 900 °C. Natural gas is found to reform ⁓130% more than methane at 800 °C and 50 mL min⁻¹ total flow rate due to low concentration hydrocarbons found in natural gas. A micro-tubular solid oxide fuel cell (mT-SOFC) is integrated into the natural gas/air microcombustion exhaust and characterized. The mT-SOFC operating in microcombustion exhaust achieves a high fuel utilization of 60% and 84% of the power density of a natural gas baseline. Three short-term tests are performed comparing the stability of natural gas and natural gas microcombustion in a mT-SOFC.