Experimental Study on Thermal and Catalytic Hydrogen Bromide Oxidation

Abstract

Hydrogen bromide (HBr) oxidation is an important part of the bromination−oxidation cycle for CO 2 -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 RuO 2 /Al 2 O 3 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.

Experimental Splitting of Hydrogen Sulfide by Halogens for Application in Reaction Cycles

“…The second step of the cycle, the production of hydrogen from HCl and HBr with simultaneous halogen regeneration is well studied, amongst other methods, electrolysis can be used to achieve that [14,15]. Halogen regeneration by oxidation with O 2 is also thinkable [16], but this reaction for HCl, the Deacon reaction [17], is rather problematic and the net reaction equation would be the same as in the Claus process, since water would also be formed as a by-product here.…”