Catalytic combustion concept for gas turbines

Catalytic combustion for gas turbines was investigated, based on a partial catalytic combustion section followed by a homogeneous combustion zone. A p ressurized test rig (<25 bar) was built to test the influence of various pa rameters on this concept using Pd and Pt catalysts. The pressure influence on the apparent catalytic reaction rate was of the o rder 0.4, assuming that the reaction kinetics could be described by a power rate function which was of first order with respect to methane. Pd catalys ts showed a pressure dependent temperature for the transition of the active PdO to the much less active Pd. Combining Pd and Pt within one catalyst re sulted in a considerably lower transition temperature. Homogeneous combustion reactions set on from 650 degrees C, depending on th e methane concentration, pressure and flow. With inlet temperatures above 8 00 degrees C the homogeneous combustion always started. At outlet temperatu res below 1050 degrees C high CO concentrations could be measured. At highe r temperatures the CO, CH4 and NOx concentrations were lower than 5 ppm. Du ring several experiments total conversion of CH4 and CO was observed. (C) 1 999 Elsevier Science B.V. All rights reserved.