Experimental Study on Thermal and Catalytic Hydrogen Bromide Oxidation

Abstract

Hydrogen bromide (HBr) oxidation is an important part of the bromination–oxidation cycle for CO2-free energy production, being the most exothermic reaction step. Although high temperatures favor reaction kinetics, equilibrium conversion decreases and thus thermal HBr oxidation is limited. A catalyst may be used to overcome thermodynamic limitations while ensuring high reaction rates, with the main drawback an increase in the costs. An experimental study has been conducted that shows that high conversions can be achieved within residence times of lower than 10 s at temperatures ranging from 800 to 1000 °C. A RuO2/Al2O3 catalyst has been synthesized and used for HBr oxidation, showing that conversions superior to 90% are achievable at temperatures as low as 200 °C with residence times inferior to 1 s.