• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.442-448
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• 2012

The effects of zeolite-type catalysts addition on the thermal decomposition of the PP resin have been studied in a thermal analyzer, a Pyrolyser GC-mass, and a small batch reactor. The zeolite type catalysts tested were natural zeolite, used FCC catalyst, and ZSM-5. As the results of TGA experiments, the pyrolysis starting temperature for PP varied in the range of $330{\sim}360^{\circ}C$ according to the heating rate. Addition of the zeolite type catalysts in the PP resin increased the pyrolysis rate in the order of used FCC catalyst> natural zeolite> ZSM-5 > PP resin. Adding the used FCC catalyst in the PP reduced most effectively the pyrolysis finishing temperature. In the PY-G.C. mass experiments, addition of zeolite type catalysts decreased the molecular weight of pyrolyzed product. In the batch system experiments, the mixing of used FCC catalyst enhanced best the initial yield of fuel oil, but the final yield of fuel oil was 2% higher in the case of mixing of natural zeolite. Also in the carbon number analysis, used FCC catalyst was the most useful one in this experiments for fuel oil.

• Resources Recycling
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• v.16 no.2 s.76
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• pp.48-55
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• 2007

A low-priced catalyst for pyrolysis of LDPE has been synthesized. Fly ash, which is waste material generated from coal-fired power plants was used as silica and alumna sources for solid acid catalyst. Amorphous silica-alumina catalysts (FSAs) were pre-pared by dissolution of silica and alumina from fly ash, followed by co-precipitation of the dissoluted ions. A series of LDPE pyrolysis were carried out in a thermogravimetric analyzer to investigate the effects of synthesis conditions such as NaOH/fly ash weight ratio and activation time one catalytic performance of FSAs. The physical properties of FSAs were examined and related to their catalytic performances. FSA(1.2-8) synthesized with NaOH/fly ash weight ratio of 1.2 and the activation time of 8 hours showed the best catalytic performance. The catalytic performance of FSA(1.2-8) was comparable with that of commercial catalysts and it was concluded that the FSA could be a good candidate for catalytic use in the recycling of waste polyolefins.

• Applied Chemistry for Engineering
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• v.29 no.3
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• pp.350-355
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• 2018

In this study, the effect of biomass torrefaction on the thermal and catalytic pyrolysis of cork oak was investigated. The thermal and catalytic pyrolysis behavior of cork oak (CO) and torrefied CO (TCO) were evaluated by comparing their thermogravimetric (TG) analysis results and product distributions of bio-oils obtained from the fast pyrolysis using a fixed bed reactor. TG and differential TG (DTG) curves of CO and TCO revealed that the elimination amount of hemicellulose in CO increased by applying the higher torrefaction temperature and longer torrefaction time. CO torrefaction also decreased the oil yield but increased that of solid char during the pyrolysis because the contents of cellulose and lignin in CO increased due to the elimination of hemicellulose during torrefaction. Selectivities of the levoglucosan and phenolics in TCO pyrolysis oil were higher than those in CO pyrolysis oil. The content of aromatic hydrocarbons in bio-oil increased by applying the catalytic pyrolysis of CO and TCO over HZSM-5 ($SiO_2/Al_2O_3=30$). Compared to CO, TCO showed the higher efficiency on the formation of aromatic hydrocarbons via the catalytic pyrolysis over HZSM-5 and the efficiency was maximized by applying the higher torrefaction and catalytic pyrolysis reaction temperatures of 280 and $600^{\circ}C$, respectively.

• Polymer(Korea)
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• v.37 no.3
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• pp.379-386
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• 2013

SAPO-11 was applied for the first time to the catalytic pyrolysis of miscanthus and random polypropylene (random PP). Thermogravimetric analysis confirmed that SAPO-11 promoted the dehydration of miscanthus while suppressing the formation of char. In the pyrolysis of random PP, the decomposition temperature and activation energy were reduced by using a catalyst. A large fraction of levoglucosan, which was the main oxygenate product from the non-catalytic pyrolysis of miscanthus, was converted to high value-added products, such as furans, phenolics and aromatics using SAPO-34. The catalytic pyrolysis of random PP produced gasoline- and diesel-range hydrocarbons.

• 대한방사선방어학회:학술대회논문집
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• 2011.04a
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• pp.166-167
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• 2011

• Journal of Energy Engineering
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• v.19 no.3
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• pp.195-202
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• 2010

A third of primary energy is lost as a waste heat. To improve this inefficient use of energy, systems using chemical reaction have been suggested and studied. In this study, methanol decomposition/synthesis reaction as a chemical reaction was selected for long time heat storage and long distance heat transport system because of safe, cheap and gaseous product. The purpose of this study is to find the optimal conditions in the methanol decomposition and synthesis reactions for long distance heat transport. Several parameters such as reaction temperature, pressure, $H_2$/CO ratio, space velocity, catalyst particle size were tested to find the effects on the reaction rates for the methanol synthesis. And the reaction temperature, space velocity, catalyst particle size were tested to find the effects on the production concentration for the methanol decomposition.

• 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.

• Resources Recycling
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• v.15 no.5 s.73
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• pp.17-25
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• 2006

Al-MCM-48 was used as a catalyst to decompose high density polyethylene(HDPE). Catalytic activity of Al-MCM-48 was compared with those of Al-MCM-41, Beta, and ZSM-5. Catalytic decomposition rate over Al-MCM-48 was much higher than at of non-catalytic pyrolysis only. Compared to other catalysts, Al-MCM-48 revealed the little higher activation energy value. The progressive deactivation behavior of the catalysts has also studied. ZSM-5 and Al-MCM-48 showed slower deactivation rates than Al-MCM-41 and Beta. Pyrolysis coupled with gas chromatographic separation and flame ionization detection (Py-GC/ FID) was also performed to assess the characteristics of pyrolysis products. ZSM-5 gave a higher fraction of gaseous products ($C_1-C_4$). Al-MCM-41 and Beta produced mainly $C_5-C_{12}$ products. The selectivity to oil product ($C_5-C_{22}$) obtained with Al- MCM-48 is higher an that with the other catalysts employed in this study.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.5
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• pp.577-583
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• 2007

To overcome certain disadvantages of past typical control techniques for toxic contaminants emitted from various industrial processes, the current study was conducted to establish a thermal catalytic system using mesh-type transition-metal platinum(Pt)/stainless steel(SS) catalyst and to evaluate catalytic thermal destruction of five chlorinated hydrocarbons[chlorobenzene(CHB), chloroform(CHF), perchloroethylene (PCE), 1,1,1-trichloroethane(TCEthane), trichloroethylene(TCE)]. In addition, this study evaluated the catalyst poison effect on the catalytic thermal destruction. Three operating parameters tested for the thermal catalyst system included the inlet concentrations, the incineration temperature, and the residence time in the catalyst system. The thermal decomposition efficiency decreased from the highest value of 100% to the lowest value of almost 0%(CHB) as the input concentration increased, depending upon the type of chlorinated compounds. The destruction efficiencies of the four target compounds, except for TCEthane, increased upto almost 100% as the reaction temperature increased, whereas the destruction efficiency for TCEthane did not significantly vary. For the target compounds except for TCEthane, the catalytic destruction efficiencies increased up to 30% to 97% as the residence time increased from 10 sec to 60 sec, but the increase of destruction efficiency for TCEthane stopped at the residence time of 30 sec, suggesting that long residence times are not always proper for thermal destruction of VOCs, when considering the destruction efficiency and operation costs of thermal catalytic system together. Conclusively, the current findings suggest that when applying the transition-metal catalyst for the better destruction of chlorinated hydrocarbons, VOC type should be considered, along with their inlet concentrations, and reaction temperature and residence time in catalytic system. Meanwhile, the addition of high methyl sulfide(1.8 ppm) caused a drop of 0 to 50% in the removal efficiencies of the target compounds, whereas the addition of low methyl sulfide (0.1 ppm), which is lower than the concentrations of sulfur compounds measured in typical industrial emissions, did not cause.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.4
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• pp.141-150
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• 2022

To abate the environmental burden derived from the massive generation of cattle manure (CM), pyrolysis of CM was suggested as one of the methods for manure treatment. In respect of carbon utilization, pyrolysis has an advantage in that it can produce usable carbon-based chemicals. This study was conducted to investigate a syngas production from pyrolysis of CM in CO₂ condition. In addition, mechanistic functionality of CO₂ in CM pyrolysis was investigated. It was found that the formation of CO was enhanced at ≥ 600 ℃ in CO2 environment, which was attribute to the homogeneous reactions between CO₂ and volatile matters (VMs). To expedite reaction kinetics for syngas production during CM pyrolysis, Catalytic pyrolysis was carried out using Co/SiO2 as a catalyst. The synergistic effects of CO₂ and catalyst accelerate the formation of H₂ and CO at entire temperature range. Thus, this result offers that CO₂ could be a viable option for syngas production with the mitigation of greenhouse gas.