• Polymer(Korea)
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• v.32 no.2
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• pp.157-162
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• 2008

To investigate the characteristics of pyrolysis for LDPE, LLDPE and HDPE, the low temperature pyrolysis was carried out in the range of 425 to $500^{\circ}C$ for 35 to 65 min. The liquid products formed during pyrolysis were classified into gasoline, kerosene, light oil and wax according to the distillation temperatures based on the petroleum product quality standard of Korea Petroleum Quality Inspection Institute. TGA experiments for three PE samples showed that the onset temperature of pyrolysis increased with increasing heating rate, and the onset temperature of pyrolysis at a fixed heating rate was in the order of LDPE$475^{\circ}C$. Yields of gasoline and kerosene were highest at $450^{\circ}C$, 65 min and decreased slightly at above $475^{\circ}C$.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.22-25
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• 2005

The thermal degradation of carbon/phenolic composite have been studied at high temperature by using thermogravimetric (TGA). A heating .ate of 5, 10, 15, 30 and $50^{\circ}C/min$ was used for the determination of thermal decomposition parameters of composite materials at high-temperature service. It has been shown that as the heating rates is increased, the peak decomposition rates are occur at higher temperature. Based on results of thermogravimetric analysis, the pyrolysis process is analyzed and physical and mathematical models for the process are proposed. The thermal analysis also has been conducted using transient heat conduction and the in-depth temperature distribution and the density profile were evaluated along the solid rocket nozzle. As a future effort the thermal decomposition parameter determined in this investigation will be used as input to thermal and mechanical analysis when subjected to solid rocket propulsion environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.3
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• pp.632-638
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• 2007

Pyrolysis experiments of HDPE and LDPE were carried out in the stainless steel reactor of internal volume of 40 $cm^3$. Pyrolysis reactions were performed at temperature $410{\sim}460^{\circ}C$ and the pyrolysis products were collected separately as liquid and gas products. The molecular weight distributions(MWDs) and composition of each product were determined by HPLC-GPC and GC analysis. It was represented that the yield and the molecular weight of liquid product were decreased with the increase of reaction temperature and time. The chain-end scission rate parameters, respectively, were determined to be 63.0kcal/mole of HDPE, 45.7kcal/mole of LDPE by the Arrhenius plot.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1996.11a
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• pp.137-144
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• 1996

The kinetic coefficients far decomposition of the cured phenol resin (SC-1008) using a modified Arrhenius relationship have been determined from thermogavimetric analyses (TGA). The kinetic parameters were determined by multiple heating rate technique developed by Freideman and Henderson. Weight loss (decomposition) and weight loss rate (decomposition rate)were measured and recorded for three heating rates; $5^{\circ}C$/min ,$10^{\circ}C$/min, and $20^{\circ}C$/min. Relatively good agreement was obtained between measured and calculated decomposition as a function of temperature. By separating the reaction, the reaction order and pre exponential factor become empirical parameters which provide a "best fit" of the data. However, this method yields an extremely accurate reproduction of the thermograms over a wide range of heating rates. This is the desired result for kinetic parameters used in thermal models.al models.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.11
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• pp.1046-1053
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• 2010

The objective of this study was to investigate the pyrolytic reaction characteristics of a mixed fuel of municipal solid wastes and low-grade anthracite. The reaction variables are pyrolysis condition of mixing ratio, reaction temperature, temperature increase rate. As a result, the optimum mixing ratio was 20 wt.% low-grade anthracite in MSW, which maintains for the low heating value over 3,500 kcal/kg on pyrolysis. The most high reaction velocity constant was shown at $700^{\circ}C$. Also, under the all experimental condition, the reaction velocity constant increased linearly as temperature rate increase, but pyrolysis has to be considered electric power cost and yield of char at lower temperature rate.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.468-470
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• 2008

열중량반응기와 미분반응기를 이용하여 ABS의 열분해 및 생성물분포 특성을 연구하였으며 미분반응기를 이용한 실험의 열분해온도는 $410{\sim}450^{\circ}C$이었다. 각 상의 열분해생성물의 수율은 무게측정을 통해 얻었으며 액상생성물의 탄소수분포는 GC-SIMDIS 방법을 통해 측정하였다. 열중량 분석실험에서는 측정할 수 없었던 다량의 고상잔류물의 생성을 회분식 미분반응기실험을 통해 확인할 수 있었다. 반응온도와 시간이 증가할수록 액상생성물의 수율과 평균분자량은 감소하였으나 액상생성물 중의 스티렌모노머의 생성은 두드러지게 증가하였다. ABS 열분해 반응에서 말단절단의 속도계수인 활성화에너지 값은 54.1kcal/mole이었다.

• Korean Chemical Engineering Research
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• v.46 no.3
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• pp.535-539
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• 2008

Conversion to oil, yield of styrene and formation of side products such as ${\alpha}-methyl$ styrene, ethyl benzene, benzene, toluene, dimer and trimer were affected by residue formed during thermal degradation. Also, control of reaction temperature had a difficulty at the first stage. Thus, new reaction system using wetted-wall type reactor was proposed and examined on various parameters such as reaction temperature, feeding rate and removal velocity of formed vapor. Optimun condition was obtained from continuous thermal degradation using wetted-wall type reactor and reaction kinetic study was carried out at new type reactor.

• Journal of Energy Engineering
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• v.17 no.1
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• pp.8-14
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• 2008

The effects of calcium type catalysts addition on the thermal decomposition of low density polyethylene (LDPE) and ethylene vinyl acetate (EVA) resin have been studied in a thermal analyze. (TGA, DSC) and a small batch reactor. The calcium type catalysts tested were calcinated dolomite, lime, and calcinated oyster shell. As the results of TGA experiments, pyrolysis starting temperature for LDPE varied in the range of $330{\sim}360^{\circ}C$ according to heating rate, but EVA resin had the 1st pyrolysis temperature range of $300{\sim}400^{\circ}C$ and the 2nd pyrolysis temperature range of $425{\sim}525^{\circ}C$. The calcinated dolomite enhanced the pyrolysis rate in LDPE pyrolysis reaction, while the calcium type catalysts reduced the pyrolysis rate in EVA pyrolysis reaction. In the DSC experiments, addition of calcium type catalysts reduced the melting point, but did not affect to the heat of fusin. Calcinated dolomite reduced 20% of the heat of pyrolysis reaction. In the batch system experiments, the mixing of calcinated dolomite and lime enhanced the yield of fuel oil, but did not affect to the distribution of carbon numbers.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1994.05a
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• pp.39-46
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• 1994

석탄이용공정에서 처음단계로 일어나는 열분해단계에 대한 석탄등급(Rank)의 영향을 고찰키 위해 Thermogravimetry/Mass Spectrometry 장치를 고안하여 실험하였다. 미국 아르곤국립연구소의 8개 표준석탄에 대하여 실험한 결과, 석탄내 각 성분들에 따라 석탄등급의 영향이 크게 차이남을 발견하였다. 따라서, 석탄내 각 성분들의 kinetic 변수들은 석탄등급에 무관하다는 기존의 가정은 석탄열분해반응의 상세모사시 적용할 수 없음이 실험적으로 확인되었다.

• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.885-888
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• 1999

This study was carried out to determine the reaction kinetic constant of the dehydration - thermal decomposition of $Na_2B_4O_7{\cdot}10H_2O/Na_2B_4O_7{\cdot}5H_2O$ and to investigate the durability during the repeated use of a chemical heat-storage material and the reproducibility of reaction system. The order of the dehydration reaction was 1st-order. The reaction rate was directly proportional to a partial pressure difference of water steam. The kinetic constant was 0.27 and the reproducibility of dehydration reaction for a kinetic constant and a reaction order was excellent. The activity variation in the durability test of a chemical heat-storage material was within range of ${\pm}5%$ during the repeatedly use in several times.