CATALYTIC COMBUSTION IN A REACTOR WITH PERIODIC-FLOW REVERSAL .1. EXPERIMENTAL RESULTS

The use of a reactor with periodic flow reversal for catalytic inciner ation of the model pollutants carbon monoxide and propane has been exp erimentally studied. The mean axial temperature profile over one perio d in cycle steady state is a symmetrical curve which can be linearised and subdivided into three regions. The center of reactor with a const ant maximum temperature and two reactor ends with a linear temperature profile. The most important parameters influencing the reactor operat ion were found to be catalytic activity, adiabatic temperature rise (r eactant concentration) and heat transfer properties of the fixed bed. Higher catalytic activity leads to a decrease of the maximum temperatu re 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 heal transfer units as a measure for the heat transfer characteristics of the catal yst bed give rise to higher maximum temperature and higher temperature gradient in the reactor ends, while the mean temperature at reactor i nlet/outlet remains constant. Investigation of the ignition and extinc tion behavior of the reactor has shown that a fixed bed with a lower n umber of heat transfer units requires higher reactant concentrations t o maintain stable operation in the ignited state. (C) 1997 Elsevier Sc ience S.A.