Effect of steam on the barium sulfate reduction by methane

Abstract

Methane gas decomposes at high temperatures and produces carbon as a result. The deposited carbon causes problems during the process. In this study, the reduction of barium sulfate powder using methane was studied and steam was used to remove the carbon produced during the reaction. The effect of temperature and methane concentration on the reaction rate was investigated at two different conditions, using 20 vol % steam and without steam at operating temperatures in the range 850–1000 °C. When steam was used, methane concentration was selected in the range 19–40 vol %, while it was 21–78 % in the absence of steam. The experimental data was interpreted using the "shrinking unreacted core model" and intrinsic kinetic parameters of the reactions were determined. The reaction order and activation energy were calculated to be 1 and 145.5 kJ/mol in the absence of steam and 1.5 and 179.6 kJ/mol in its presence, respectively. From the obtained rate equations, it was found that the reaction rate without steam was always faster than the reaction rate in the presence of steam.