**2.4. Hydrogen production**

Production of hydrogen from gases such as methane and hydrogen-sulphide is another potential application of PM combustion. These reactants convert into products such as hydrogen, syngas (H2 and CO), and sulfur. For both methane and hydrogen-sulphide combustion, upstream propagation corresponded to the range of equivalence ratios from stoichiometry to 1.7, and downstream wave propagation was observed for ultra-rich (1.7- 4) mixtures.
