Abstract Laboratory studies of the reaction of steam reforming of light hydrocarbons into methane–hydrogen mixture were performed. Ni- and Ru-containing systems were studied as the catalysts. The design, scale-out, and operation of an APG catalytic reformer integrated with evaporator-heat-exchanger, water condenser and flame burner were reported. Conversion of heavier hydrocarbon components into methane–hydrogen gas mixture exceeded 95–99% during testing the catalytic reformer at 270–360 °C. Increasing reaction temperature led to increasing H2 and CO contents in the reaction mixture and complete conversion of LPG and ethane fractions. Both initial and reformed APG were used for fueling a power generation unit on the base of gas internal combustion engine MTES-30. In case of initial APG fueling, the power derating was 22%, exhaust gas contained black smoke. When the power generation unit was fueled by methane–hydrogen mixture produced by APG catalytic reforming, the engine power attained the nominal value; the engine showed excellent dynamic and temperature characteristics, stably supported crank rotation frequency. According to economic analysis concerning different types of power plants with electric power of ∼1000 kW, the plants equipped with a catalytic reformer of APG into methane–hydrogen mixture show faster payback of capital investments, as compared to the plants fed by APG directly, due to longer service life, longer overhaul intervals, and low rated power losses. Сatalytic reforming of APG into methane–hydrogen mixture is a promising approach for solving APG utilization problem.