Catalytic combustion in a reactor with periodic flow reversal. Part 1. Experimental results

The use of a reactor with periodic flow reversal for catalytic incineration of the model pollutants carbon monoxide and propane has been experimentally studied. The mean axial temperature profile over one period in cycle steady state is a symmetrical curve which can be linearised and subdivided into three regions. The center of reactor with a constant maximum temperature and two reactor ends with a linear temperature profile. The most important parameters influencing the reactor operation were found to be catalytic activity, adiabatic temperature rise (reactant concentration) and heat transfer properties of the fixed bed. Higher catalytic activity leads to a decrease of the maximum temperature profile. Increasing reactant concentrations cause higher values of maximum temperature, temperature gradient in the reactor ends and mean temperature at reactor inlet/outlet. A higher number of heat transfer units as a measure for the heat transfer characteristics of the catalyst bed give rise to higher maximum temperature and higher temperature gradient in the reactor ends, while the mean temperature at reactor inlet/outlet remains constant. Investigation of the ignition and extinction behavior of the reactor has shown that a fixed bed with a lower number of heat transfer units requires higher reactant concentrations to maintain stable operation in the ignited state.