Numerical Simulation of Making Hydrogen from Rich Filtration Combustion of Hydrogen Sulfide

Filtration combustion in porous media offers good advantages such as super-adiabatic combustion temperature in making hydrogen from hydrogen sulfur which is extremely toxic and is vastly produced in industry. In order to study the mechanism of making hydrogen from rich filtration combustion of hydrogen sulfur, computational fluid dynamics (CFD) were employed combining with a detail H₂S oxidation mechanism to model the filtration combustion of hydrogen sulfide in a packed bed of uniform 3 mm diameter alumina spherical particles. The standard k-ε turbulence model and a detail H₂S oxidation mechanism with 17 species and 57 elemental reactions were adopted, and several equivalence ratios φ (1.0-4.0) were investigated. The numerical results agreed well with the experimental data, indicating that the combination of CFD with detail chemical kinetics gives good performance in modeling the anisotropic filtration flames. The combustion temperature exceeds the theoretical adiabatic combustion temperature by over 300 K, offering high temperature to decompose the hydrogen sulfide to hydrogen up to a conversion rate of 20%. On the other hand, the simulated combustion temperatures were relatively lower than the experimental data, resulting that much more un-burnt H₂S (3.6% in simulation and 2.2% in experiment when φ=2.0) existed at the outlet. However, the predicted hydrogen concentrations were larger (3.3% in simulation and 2.0% in experimental when φ=2.0) than those measured in experiment.