Measurements of reactant temperature and free-radical concentrations during the oscillatory combustion of hydrogen and carbon monoxide in a CSTR

Abstract

Experimental studies in which the phase relationship between a reactive intermediate concentration and reactant temperature during the gas-phase, oscillatory combustion of hydrogen + carbon monoxide mixtures in a non-adiabatic CSTR are reported. This combustion reaction and its counterpart, hydrogen oxidation, constitutes the simplest of the non-isothermal, quadratic autocatalytic systems. The hydroxyl radical (OH) is a primary propagating species. Measurements of the laser-induced absorption spectrum of OH during oscillatory reaction led simultaneously, via data capture and analysis by computer, to absolute concentrations of the species and to the reactant temperature. The results show that there is a considerably reduced reactivity of the carbon monoxide-containing reaction when compared with the results obtained previously from hydrogen oxidation. The OH concentration and reactant temperature remain in phase during the oscillatory combustion.