The cracking of heptane (HEP) and the cracking of the binary system of triethylamine/heptane (TEA/HEP) in a continuous tubular reactor at 3.5 MPa are studied, to test the effect of triethylamine on the pyrolysis of heptane under a supercritical condition. It is found that triehtylamine can promote the cracking of heptane under the supercritical condition, and more effective in lower temperatures. The selectivity of ethane, ethylene, propylene, and C4 by pyrolysis of TEA/HEP is notably higher than that by HEP in a low temperature, while the difference of the selectivity is weak when in a high temperature. The kinetic character of the cracking of heptane under the supercritical condition is studied, through which the activation energy and the pre-exponential factor are obtained by pseudo-isothermal method with a quick convergence process.(c) 2008 Elsevier Ltd. All rights reserved.