Partial Oxidation of Methane–Ammonia Mixture in a Tubular Porous Structure With Efficient Preheating System

Ammonia has attracted considerable attention as a carbon‐free fuel due to its potential to reduce greenhouse gas emissions. Blending ammonia with more reactive fuels solves the challenges associated with its direct utilization. To investigate the combustion characteristics of methane–ammonia mixture, a novel tubular porous media combustion system integrated with a spiral heat exchange tube was built. The effects of the gas mixing ratio, tubular structure and operating parameters on combustion performance were examined. The results show that the combustion temperature decreases with an increasing ammonia fraction, and the partial oxidation of methane is partially inhibited by ammonia addition. Regarding burner structure, a higher combustion temperature is achieved when using corundum tubes as the internal filling compared to Al 2 O 3 pellets. Specifically, the methane conversion efficiency reaches its maximum at a corundum tube diameter of 30 mm. In the 4(2) structure, corundum yields the highest hydrogen concentration, while stainless steel obtains the highest methane conversion efficiency. Moreover, the stainless steel burner produces syngas with a lower heating value 200.4 MJ/kg, higher than that obtained with corundum tubes. These findings indicate that adjusting the gas mixing ratio and optimizing the burner internal structure significantly optimize the combustion performance of methane–ammonia mixtures.