Fuel-flexible matrix-stabilized combustion of methane/hydrogen mixtures using a non-premixed injection system.

For many industrial and power generation applications, the transition towards low-carbon energy carriers will require adapting burners and combustion systems to operate with a wide range of natural gas and hydrogen mixtures. Matrix-stabilized combustion is an attractive option to stabilize methane/hydrogen flames at very lean conditions. The current work investigates the utilization of an additively manufactured non-premixed fuel injector in conjunction with ceramic foams to mitigate the risk of flashback when operating with a high hydrogen fuel mix. The burner is an axial-flow interface-stabilized design, made of silicon carbide and yttria-stabilized zirconia alumina reticulated foams. The injector was additively manufactured from a nickel alloy and used a coaxial injector setup. This design is optimized to achieve mixing in the near field of the injectors, enabling quasi-premixed combustion within the downstream porous media section. The burner's stability limits and emissions were measured and compared to a fully premixed design. This novel design improves the flashback resistance of the burner while maintaining the beneficial low emission and extinction resistant characteristics of traditional premixed matrix-stabilized combustion.