Catalytic pyrolysis of n-heptane: Kinetics and modeling

Steam pyrolysis of n-heptane has been studied over potassium carbonate impregnated calcium aluminate (12CaO-7Al(2)O(3)) catalyst in a fixed bed reactor at atmospheric pressure in the temperature range of 953-1023 K. Compared to noncatalytic pyrolysis, the conversion and product yields of methane, ethylene, and propylene were significantly higher in the presence of the catalyst. Incorporation of K2CO3 in the catalyst significantly reduced the coke deposited on the catalyst. The overall catalytic pyrolysis reaction could be represented by a first-order reaction with a preexponential factor of 1.7 x 10(3) m(3)/(kg.s) and an activation energy of 103.8 kJ/mol. The experimental product yields could be satisfactorily modeled by use of a molecular reaction scheme, consisting of a first-order primary reaction and 24 secondary reactions among the primary products.