The conversion of hydrocarbon gases to synthesis gases via partial oxidation in a novel type of reversed flow porous medium reactor is investigated. The reactor is distinguished by separate supply of the hydrocarbon and the oxidant gas. A calculation scheme is given for the combustion regimes and composition of synthesis gas as controlled by the flowrates of the reactants. The calculation is performed under assumption of thermodynamic equilibrium in the combustion products and zero heat loss through the reactor walls. Calculations for the methane-steam-oxygen/air reaction system show that proposed reactor type provides a possibility to combine a high combustion temperature with low net heat effect and thus, a high chemical efficiency of conversion. (C) 2016 Elsevier B.V. All rights reserved.