화학공학소재연구정보센터
Korean Chemical Engineering Research, Vol.42, No.3, 280-287, June, 2004
미분열중량곡선의 극점 특성치를 이용한 HDPE 열분해 동역학변수 결정에 대한 연구
Estimation of Pyrolysis Kinetic Parameters of HDPE by using Peak Properties of DTG Curve
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초록
본 연구의 목적은 최근 개발된 peak property method (PPM)를 이용하여 HDPE의 동역학변수를 결정하고, 그 타당성을 검증하는데 있다. 이를 위해서 이론 미분중량곡선(derivative thermogravimetry: DTG)과 실험 결과를 비교하였고, 기존의 대표적 분석 방법을 이용하여 HDPE의 동역학변수를 결정하고, 그 결과와 비교 평가하였다. 또한 문헌 결과와도 비교하여 PPM의 타당성을 여러 경로를 통해 검증해 보았다. PPM은 DTG곡선의 세 극점 특성치인 극점온도, 극점높이, 극점전화율이 특정 열분해 반응을 대표할 수 있다는 가정에 근거하여 개발되었다. PPM에 의해 HDPE의 열분해 반응의 활성화에너지는 251.92 kJ/mol, 전자수인자는 1.70 × 1017 min-1, 반응차수는 0.581로 결정하였다. 이 결과는 기존 연구에 의해 보고된 [1] DTG curve fitting method 결과와 상당히 유사하였다. 그러므로 PPM은 DTG곡선을 훌륭히 모사할 수 있으며, 단일 DTG 곡선의세 극점값만으로도 동역학변수를 동시에 간편하고 정확하게 결정할 수 있다. 그러나 PPM은 전화율 함수가 power law 함수인 경우에만 적용 가능한 한계를 지니고 있다.
This research was designed to determine the pyrolysis kinetic parameters of HDPE using Peak Property Method (PPM) which was recently developed. The properness of PPM was verified by comparing theoretical Derivative Thermogravimetry (DTG) curve with experimental one. The kinetic parameters derived from PPM was compared with those estimated from typical analysis methods and those reported by previous studies. The PPM was developed based on the assumption that a specific pyrolysis reaction would be characterized by three peak properties of DTG curve: peak temperature, peak height, and conversion at peak temperature. The activation energy, pre-exponential factor, and reaction order of HDPE pyrolysis reaction, respectively, were 251.92 kJ/mol, 1.70 × 1017 min-1, and 0.581, demonstrating good agreement with those estimated by DTG curve fitting method[1]. The PPM simulates experimental DTG curve excellently and it was proved that the three peak properties of DTG curve would be enough to represent a unique thermal reaction. The pyrolysis kinetic parameters would be estimated easily but accurately by the PPM. However, the PPM is only applicable for a reaction which is represented by a conversion function of power law equation.
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