INCIPIENT PHASE OF THE CATALYTIC IGNITION OF LEAN n-HEPTANE-AIR MIXTURE

The incipient phase of catalytic ignition of 1.20% n-heptane-air over the surface of a heated platinum wire has been investigated at atmospheric pressure. The experimental setup allowed for ignition in isothermal condition, with quasi-rectangular rise of the wire temperature, and the recorded electrical signals accounted for compensation of the energy delivered by the chemical reaction over the catalytic surface. Activation energy was calculated via either induction period or slope of the incipient kinetic regime curve, denoted by very slow increase of the reaction rate – time dependency. The difference of the two quantities allowed for the evaluation of the energy contribution of the chemical reaction. The results are compared with previous findings for fuels of lower molecular mass.