• Clean Technology
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• v.13 no.2
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• pp.104-108
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• 2007

Biodiesel is a fatty acid alkyl ester produced by chemical reaction of a vegetable oil or animal fat and an alcohol. It is getting attention as a clean alternative energy that can replace gas oils. In this study, strong acidic ion exchange resin was introduced in the pretreatment process of the used cooking oil and rapeseed oil to enhance the conversion of the oil to the biodiesel by removing FFA(free fatty acid). More than 90% FFA was removed. Dry resins showed higher FFA removal efficiency than wet resins. Using transesterification the conversion of triglyceride into fatty acid methyl ester was raised up to 98%. These results can be applicable to the pretreatment of biodiesel feedstocks having high acidic value.

• Journal of the Korean Society for Railway
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• v.14 no.2
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• pp.188-193
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• 2011

In order to solve urban transportation problems, the various alternatives are presented to the public transportation system but the master plan of construction and operation is that there is no validity. PRT unlike other public transport system, is a new transport system that can respond appropriately, to solve the traffic demand, environmental and energy problems. Meanwhile, national and international PRT system was not commercially and the actual construction and operation of the PRT in case of base research is not well established. In this paper, PRT concept was established as the new transportation system, the target area(Nan-gok area) was selected to examine the feasibility of PRT systems and the corridor analysis method has been developed to predict the PRT demand as a basic material of planning process.

• KSBB Journal
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• v.5 no.1
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• pp.9-17
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• 1990

The growth and fermentation profiles of Clostridium acetobutylicum KCTC 1037 were examined in batch and continuous modes with pH variation and phosphate limitation. Clostridium acetobutylicum KCTC 10 37 grew better at pH 4.5 than at pH 5.5 or 6.5. Acetate and butyrate were produced at pH 5.5, whereas culture at pH 4.5 produced acetone and butanol. Solvent production was increased by the phosphate limitation in a batch culture, but in a phosphate-limited continuous culture for 400 hours steady-state solventogenesis was not observed. The induction and maintenance of solventogenesis presumably require not only acidic condition or phosphate limitation but also favourable bioenergetic condition.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.6
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• pp.1063-1072
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• 2000

Kinetic tests on pyrolysis of the mixture of waste automobile lubricating oil and polystyrene were carried out with thermogravimetric technique at the heating rates of 0.5, 1.0, $2.0^{\circ}C/min$ in a stirred batch reactor. The activation energy and the reaction order were determined at conversions of 1 to 100% using differential method. The mixture of waste automobile lubricating oil and polystyrene was pyrolyzed at lower temperature rather than waste automobile lubricating oil and polystyrene. respectively. Also, the thermal decomposition took place in two broad reaction steps. The pyrolyzed oil of mixture represented high selectivity of styrene monomer and dimer like that of polystyrene pyrolyzed products.

• Polymer(Korea)
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• v.29 no.1
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• pp.64-68
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• 2005

To recycle collected high-impact polystyrene (HIPS) wastes as liquid fuel, depolymerization characteristics of HIPS by pyrolysis was studied. The effects of temperature and time on the pyrolysis of HIPS were investigated. The depolymerization temperature and activation energy of HIPS pyrolysis increased with increasing heating rate. In general, conversion and liquid yield gradually increased with pyrolysis temperature and pyrolysis time. Each liquid product formed during pyrolysis was classified into gasoline, kerosene, light oil and heavy oil according to the distillation temperature based on the petroleum product quality standard of Korea Petroleum Quality Inspection Institute. As a result, the amount of liquid products produced during HIPS pyrolysis was in the order of gasoline》heavy oil〉kerosene〉light oil. Especially 51${\pm}$6 wt% of HIPS treated was obtained as gasoline.

• Applied Chemistry for Engineering
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• v.27 no.2
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• pp.190-194
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• 2016

Tricyclopentadiene (TCPD) is one of the important precursors for making tetrahydrotricyclopentadiene, which is well known as a next-generation fuel with high energy density. In this study, TCPD was obtained by polymerization reaction of dicyclopentadiene (DCPD) using an ionic liquid (IL) supported mesoporous silica catalysts. ILs were supported to two kinds of mesoporous silica catalysts with different pore sizes such as MCM-41 and SBA-15. Four different ILs were supported to mesoporous silicas using anionic precursors such as CuCl or $FeCl_3$ and cationic precursors such as triethylamine hydrochloride or 1-butyl-3-methylimidazolium chloride. We proved that IL supported mesoporous silicas showed better catalytic performance than those of using non-supported prestine IL in the aspect of TCPD yield and DCPD conversion. Among four kinds of IL supported mesoporous silica catalysts, CuCl-based IL supported MCM-41 system showed the highest TCPD yield.

• 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.

• Journal of the Korean Institute of Gas
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• v.27 no.1
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• pp.78-85
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• 2023

Fixed-bed reactor Computational Fluid Dynamics (CFD) simulation of methanol steam reforming reaction was performed using the intrinsic kinetic data of the copper-impregnated hydrotalcite catalyst. The activation energy of the copper hydrotalcite catalyst obtained from the previous study results was 97.4 kJ/mol, and the pre-exponential was 5.904 × 10¹⁰. Process simulation was performed using the calculated values and showed a similar tendency to the experimental results. And the conversion rate according to the change of the reaction temperature (200 - 450 ℃) and the molar ratio of methanol and water was observed using the intrinsic kinetic data. In addition, mass and heat transfer phenomena analysis of a commercial reactor (I.D. 0.05 - 0.1m, Length 1m) was predicted through axial 2D Symmetry simulation using the power law model of the above kinetic constants.

• Membrane Journal
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• v.33 no.6
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• pp.305-314
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• 2023

Various methods for removing by-products from chemical reactions are being studied to improve yield of catalytic reaction. Since the water is predominantly generated as a by-product in industrially significant reactions, it is necessary to develop the technology that can reliably remove water over a wide range of temperatures. Although several strategies using absorbents and additional dehydration reactions, have been proposed, they have limitations due to the issues such as additional energy and time consuming steps and sustainability of conversion. Membrane technology, which offers advantages such as easy operation, installation, and low maintenance costs, proves to be a promising approach for enhancing the efficiency of catalysts in various catalytic reactions. Therefore, this review discusses the removal of by-products using membranes and the associated benefits in this context.

• Journal of Climate Change Research
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• v.1 no.2
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• pp.163-177
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• 2010

This study analyzes the economies of photovoltaic systems in an apartment complex of 1,185 households, in cases of feed-in tariff and subsidy for solar home program of the government. When including the revenue only from electricity sales, NPVs of subsidy and that of feed-in tariff are -560 million KRW and -87 million KRW respectively. With the avoided social cost included without the revenues from CERs, NPVs of subsidy and feed-in tariff are -556 million KRW and -84 million KRW respectively. With the revenues from CERs, NPV of subsidy is -526 million KRW and NPV of feed-in tariff is -54 million KRW. As results of sensitivity analysis based on the changes in capital costs and discount rates, while all scenarios with subsidy including the revenues from CERs are not commercially viable, all scenarios with feed-in tariff exclusive of the revenues from CERs are commercially viable when discount rate is less than 7.2% or capital cost is less than 6,840 thousand KRW/kW. In the cases that include the avoided social cost, while all scenarios with subsidy including the avoided social cost as well as the revenues from CERs are not commercially viable, all scenarios with feed-in tariff are commercially viable without the revenues from CERs when discount rate is less than 7.2% or capital cost is less than 6,856 thousand KRW/KW. The results indicate that the changes in discount rates do not influence the revenues from CERs, but the revenues from electricity sale. Considering that the number of apartment complex and the positive environmental and social benefits from PV system, government needs to promote its diffusion.