(335c) Stability and Kinetic Study of Barium Manganese Hexa-Aluminate Catalysts for Catalytic Combustion of Natural Gas

In recent years, catalytic combustion of natural gas as an alternative to traditional thermal combustion has received significant attention due to its ability to achieve ultra low levels of NOx emissions owing to lower temperatures. For the successful commercialization of this technology, active catalyst materials which are stable at high temperatures are necessary. A promising class of materials, in this regard are metal substituted barium hexa-aluminates. The unique layered crystal structure makes them resistant to sintering even at temperatures above 1200 °C. In order to be commercially viable, the catalysts must retain their activity for extended periods of operation.

The present study focuses on the long term stability and activity of barium manganese hexa-aluminate catalysts. The catalytic reactor was fed with about 3.8 % methane-air mixture and operated for over 500 hours under maximum temperatures exceeding 800 C . During this period, periodic activity testing of these catalysts was performed to yield the activity history of catalyst. Deactivation after the initial ageing at high temperatures was observed. Possible reasons for this initial deactivation have been investigated. Investigation into the kinetics of the catalysts was done to provide empirical rate models for theoretical simulation of the catalytic reactor.