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The study compares the performance of different pathways for gas-phase (non-catalytic) fuel reforming between 600 and 1000 °C. Specifically, the conversion of propane to hydrogen-rich syngas was investigated numerically and experimentally for pyrolysis (Py), steam reforming (SR), partial oxidation (POx), and autothermal reforming (ATR). Experiments were conducted in a tubular quartz reactor, where temperatures were imposed externally; reactants were diluted with nitrogen to reduce the impact of endothermic/exothermic reactions on the variation of gas-phase temperatures. In experiments, product concentrations of hydrogen, carbon monoxide, carbon dioxide, methane, and a range of hydrocarbon species were measured at predetermined operating conditions. The performance of each homogeneous reforming process was evaluated and compared by assessing propane conversion and production efficiencies for hydrogen and other species of interest. At 600 °C, propane conversion was low, but increased substantially with temperature; complete conversion was achieved at 1000 °C. Furthermore, findings show improved hydrogen production efficiencies of POx/ATR when compared to Py/SR. Experimental results are substantiated by numerical simulations with detailed chemical kinetics; numerical results are in good agreement with experiments at identical operating conditions. Experimental and numerical results for non-catalytic propane reforming at all tested temperatures (600–1000 °C) imply a negligible impact of steam addition to the process, as results for SR resemble Py results, and ATR closely follows POx characteristics. As such, results clearly show that steam does not play an active role in gas-phase reforming of propane at intermediate temperatures.

Although hydrogen is abundant in nature, it is primarily bound into other molecules such as hydrocarbons. The conversion, or reforming, of a hydrocarbon into a hydrogen-rich syngas may be accomplished through either catalytic or non-catalytic processes. In this paper, we examine a non-catalytic reactor for syngas production that consists of multiple parallel channels with alternating flow directions. Heat recirculation between channels with opposing flow directions promotes reactions of rich mixtures beyond the conventional flammability limit. Experimental results with propane/air mixtures show that stable reaction fronts are obtained at a wide range of equivalence ratios and inlet velocities. The performance of the reactor with propane/air is compared to previously published results with methane/air mixtures, where significant differences are attributed to the more complex reaction chemistry of rich propane combustion.