• Applied Chemistry for Engineering
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• v.18 no.1
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• pp.36-40
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• 2007

The study on the isomerization reaction of endo-tetrahydrodicyclopentadiene and endo-tetrahydrodi(methylcyclopentadiene) using heteropolyacid catalyst was carried out. Exo compound was prepared from endo compound through isomerization reaction. To improve the problem of aluminum chloride as an isomerization catalyst, application of heteropolyacid was attempted. In use of Keggin type heteropolyacid, catalytic activity was extremely high at cesium substitution instead of 2.5 hydrogen atoms of $H_3PW_{12}O_{40}$. Using the cesium substituted heteropolyacid, isomerization reaction rate was faster than aluminum chloride and the effect of reaction temperature and times on reactivities were compared in isomerization of tetrahydrodicyclopentadiene and tetrahydrodi(methylcyclopentadiene).

• Korean Chemical Engineering Research
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• v.57 no.6
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• pp.763-767
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• 2019

In this study, thermal decomposition characteristics of exo-tetrahydrodicyclopentadiene (exo-THDCP) composed with a single compound were analyzed by using a flow reactor. The experiments were carried out at $500^{\circ}C$, 50 bar and the products of each flow rate condition were analyzed by using a GC/MS. As a result, it was confirmed that exo-THDCP was decomposed mainly into cyclic compounds and a part was isomerized by heat. As the flow rate was increased, the kinds and ratio of compounds produced through the decomposition and isomerization were decreased. Also, the conversion rate of exo-THDCP and the amount of heat absorbed during the decomposition were also decreased. The compounds rapidly produced by decomposition were mainly formed through the radical form of 1-cyclopentylcyclopentene (1-CPCP) which is one of the intermediates that can be formed from exo-THDCP because it has the lowest activation energy of 42 kcal/mol.

• Applied Chemistry for Engineering
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• v.25 no.1
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• pp.66-71
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• 2014

Synthesis of exo-tetrahydrodicyclopentadiene (exo-THDCPD) through the isomerization of endo-tetrahydrodicyclopentadiene (endo-THDCPD) was investigated over HY zeolite catalysts. Conversion of endo-THDCPD increased with the increase of $Si/Al_2$ ratio of HY zeolite catalysts, which can be attributed to increase of acid strength with increase of $Si/Al_2$ ratio. Yield of exo-THDCPD, however, was the highest over HY with $Si/Al_2$ ratio of 30, because the production of cyclopentadiene and oligomers was minimized. The optimal reaction temperature was $180^{\circ}C$ because the higher reaction temperature increased the production of by-products. The yield of exo-THDCPD also increased with the amount of the catalyst in feed. In the isomerization reaction of endo-THDCPD using the HY zeolite catalysts, it was confirmed that the internal diffusion resistance in the pore of catalysts would have more significant effects on the reaction activity than that of the external diffusion resistance of catalysts.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.991-994
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• 2017

In hypersonic aircraft, increase of aerodynamic and engine heat lead thermal load in airframe. It could lead structural change of aircraft's component and malfunctioning. Endothermic fuels are liquid hydrocarbon fuels which are able to absorb the heat load by undergoing endothermic reactions. In this study, we investigated the method of measuring the heat sink of catalyst by using exo-tetrahydrodicyclopentadiene as a fuel in a packed bed flow reactor similar to the actual reaction conditions.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.5
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• pp.81-87
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• 2018

In hypersonic aircraft, increase of aerodynamic and engine heat lead thermal load in airframe. It could lead structural change of aircraft's component and malfunctioning. Endothermic fuels are liquid hydrocarbon fuels which absorb the heat load by undergoing endothermic reactions. In this study, we investigated the relationship between product, coke formation and catalytic properites of endothermic catalysts by using exo-tetrahydrodicyclopentadiene as a fuel in a fixed bed flow reactor similar to the actual reaction conditions.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.3
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• pp.56-60
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• 2017

In hypersonic aircraft, increase of aerodynamic heat and engine heat leads heat loads in airframe. It could lead structural change of aircraft's component and malfunctioning. Endothermic fuels are liquid hydrocarbon fuels which are able to absorb the heat load by undergoing endothermic reactions. In this study, exo-tetrahydrodicyclopentadiene was selected as a model endothermic fuel and experiments were investigated in endothermic fuel cooling system with zeolite catalyst. Three shapes of catalysts have been manufactured and endothermic characteristics were recovered. Bineded catalyst showed higher heat absorption and conversion than other two zeolite catalysts. In product distribution, binded catalyst showed higher aromatics composition.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.5
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• pp.95-100
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• 2014

In hypersonic aircraft, increase of aerodynamic heat and engine heat leads heat loads in airframe. It could lead structural change of aircraft's component and malfunctioning. Endothermic fuels are liquid hydrocarbon fuels which are able to absorb the heat load by undergoing endothermic reactions. In this study, exo-tetrahydrodicyclopentadiene was selected as a model endothermic fuel and experiments on endothermic properties were investigated with pore structure controlled zeolite catalyst using metal deposition. We secured the catalyst that had better endothermic performance than commercial catalyst. The object of this study is inspect catalyst properties which have effect on heat absorption improvement. Synthetic catalyst could be applied to system that use exo-THDCP as endothermic fuel instead of other commercial catalyst.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.5
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• pp.48-53
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• 2011

We investigated thermal stability improvement of exo-tetrahydrodicyclopentadiene (exo-THDCP) with thermal stabilizers (additives). The reaction products were sample during the reactions. The compositions of products were determined by gas chromatography-mass spectrometry (GC-MS) to measure thermal decomposition products of exo-THDCP and to specify mechanism for thermal stabilizers. Hydrogen donors (thermal stabilizers) such as 1,2,3,4-tetrahydroquinoline (THQ), benzyl alcohol (BnOH) increased thermal stability of exo-THDCP. These materials donated hydrogen to radical of exo-THDCP produced after initiation of exo-THDCP. We found that stabilization of exo-THDCP radicals decreased activity of primary products of exo-THDCP and lowered formation of secondary products (above-$C_{11}$ products).

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.294-299
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• 2010

Thermal stability of exo-tetrahydrodicyclopentadiene (exo-THDCP) were investigated in a batch-type reactor perfectly coated with quartz. The 1 ml liquid product, which was a sufficiently small amount so as not to affect the reaction pressure, was sampled at 90 min intervals during the reaction and determined by gas chromatography-mass spectrometry (GC-MS) to measure thermal decomposition products of exo-THDCP and specify mechanism for additives (thermal stabilizer). Hydrogen donors (thermal stabilizer) such as 1,2,3,4-tetrahydroquinoline (THQ), benzyl alcohol (BnOH) increased thermal stability of exo-THDCP. These materials donated hydrogen to radical of exo-THDCP produced after initiation of exo-THDCP to decrease activity of primary products of exo-THDCP.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.193-196
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• 2006

This paper presents the results of catalytic endo- to exo- isomerization of saturated poly cyclic compound. Several zeolites were tested and influences of, Si/Al ratio and Structures of the zeolites on the reaction were investigated. The results showed that Y zeolites were more active than other zeolites, because of its large pore size and relative strong acidity. In all Y zeolites with different Si/Al, Y-5.4 is best. In all the zeolites tested, Y calcined at $450^{\circ}C$ was favorable. Still now the aluminium chloride catalyst is more active than zeolites. However, considering of environmental problems, corrosion, and treatment can make the zeolite catalyst substitute the aluminium chloride catalyst.