Using peak properties of a DTG curve to estimate the kinetic parameters of the pyrolysis reaction: application to high density polyethylene

This paper introduces the peak property method (PPM) which can concurrently estimate the three kinetic parameters (reaction order, activation energy.. and pre-exponential factor) of a pyrolysis reaction from a single derivative thermogravimetry (DTG) curve. A key assumption of the PPM is that a specific combination of three peak properties (peak temperature, peak height, and conversion at peak temperature) of a DTG curve would confine a unique thermal reaction. Theoretical relationships between the peak properties and the kinetic parameters were derived and its validity was checked by means of applying to estimation of pyrolysis kinetics of high density polyethylene (HDPE). Theoretical DTG curves derived from the PPM were in good agreement with the experimental ones at four heating rates. The PPM has an advantage of concurrent determination of three kinetic parameters in a simple but accurate way. However, its application is limited to a case of which the conversion function is accounted for by a power law equation. (C) 2004 Elsevier Ltd. All rights reserved.