Dual behavior of hydrogen peroxide in gaseous detonations

The paper describes the dual behavior observed for hydrogen peroxide when added to hydrogen-air detonating mixtures. The effect of the addition of hydrogen peroxide on NOx emissions and critical detonation parameters was evaluated for H2 air mixtures using one-dimensional ZND calculations. Hydrogen peroxide acts as an ignition promoter and is shown to significantly enhance the detonation chemistry when added in small concentrations. It alters the ignition chemistry of an underlying detonation wave without affecting the bulk thermodynamic properties. The main objective of the present study is to evaluate the ignition promotion and NOx mitigation effects of hydrogen peroxide in gaseous detonations when it is added to hydrogen-air mixtures in small and large concentrations. In the current work, the diminishing sensitizing potential of hydrogen peroxide when added in large amounts (up to 10%) is also reported. The results show a visible effect on ignition promotion up to 20,000 ppm. At concentrations higher than 20,000 ppm of H2O2, further reduction in the induction length was found to be minimal. The NOx emissions were found to decrease for stoichiometric and fuel-lean H2-air mixtures, whereas the NOx concentration was found to increase for fuel-rich mixtures with the addition of hydrogen peroxide. Thus, the dual behavior exhibited by H2O2 is shown to be advantageous as it could potentially mitigate NOx emissions at high temperatures for fuel-lean and stoichiometric hydrogen-air mixtures and, at the same time, could sensitize the given mixture for applications in detonation-based combustors.