• Journal of Energy Engineering
• /
• v.24 no.4
• /
• pp.42-47
• /
• 2015

While the oxygen content of gasoline for automobiles in Korea is regulated to less than 2.3 weight %, European and World-Wide Fuel Charter (WWFC) regulate it to less than 2.7 weight %. The oxygen content of oxygen-containing materials increases the octane number of the fuel due to the secondary combustion in the internal combustion engine. It has been reported to be effective in reducing emissions, such as CO, HC, which is caused by incomplete combustion. Before 2000s in the United States and Europe, there has been many researches about vehicle application of the changes in oxygen content of gasoline. However, there are not many domestic researches which reflect the improvement of the fuel quality and automotive technology. In this study, fuels of three different oxygen contents were applied to GDI and MPI engines. As a result, the changes of fuel consumption and emission gas were very similar depends of the oxygen content changes. The PN in GDI engine was decreased as the oxygen content was increased.

• Applied Biological Chemistry
• /
• v.41 no.1
• /
• pp.84-88
• /
• 1998

Composition of volatile flavor components of chestnut flower sand honey were investigated by GC and GC-MS. A total of 64 components including 14 aromatic compounds, 13 hydrocarbons, 7 fatty acids, 4 terpenes, 12 oxygenated hydrocarbons, and 7 misellaneous compounds and a total 41 components including 7 aromatic compounds, 16 hydrocarbons, 12 fatty acids, 1 terpene, 2 oxygenated hydrocarbons, and 3 misellaneous compounds were identified from total volatile concentrates of chestnut flower and honey respectively. The main components of flower volatile were 2-phenyl ethyl alcohol, 1-phenyl ethyl alcohol and benzyl alcohol which comprise 49.02% of this volatiles The main components of flower volatile were 2-phenyl ethyl alcohol, 1-phenyl ethyl alcohol and benzyl alcohol which comprise 49.02% of this volatiles. Aromatic compounds such as 2-phenyl ethyl alcohol, benzyl alcohol, 1-phenyl ethyl alcohol, 1-(2-aminophenyl) ethanone act as major contributor to the characteristic honey-like flavor of chestnut honey.

• Resources Recycling
• /
• v.1 no.1
• /
• pp.51-57
• /
• 1992

The hydrochloric acid leaching has been studied as a fundamental experiment on the recovery of arsenic from arsenic-bearing copper slime in copper electrorefining. The slime is mainly composed of $\beta-Cu_3As$ Which is intermetallic compound of CU and As. And the minor components are $CU_2O$ and CusAs in the slime. The optimum conditions of leaching of the slime were found to be as follows : 6N hydrochloric acid, particle size passed through 140 mesh, leaching for 150 min at $60^{\circ}C$, ratio of HCI/slime of 3 to 1 ; where 98 percent of arsenic were leached out of the As-bearing slime.

• Korean Journal of Food Science and Technology
• /
• v.20 no.2
• /
• pp.157-163
• /
• 1988

The volatile compounds produced from the browning reaction of 0.5M DL-alanine and 0.5M D-glucose mixture using propylene glycol as a reaction medium were analysed by gas chromatography and gas chromatography-mass spectrometry and effects of temperature($100^{\circ}C,\;120^{\circ}C,\;140^{\circ}C$) and time(20min, 2hours) on the formation of volatile compounds were investigated. Browning reaction were rapidly increased as the reaction temperature and time increased. From methylene chloride extracts, twenty six compounds, including 7 alkyl pyrazines. 4 pyrroles, 3 furans, 1 furanone and 11 miscellaneous compounds were identified. The relative amounts of pyrazines, pyrroles and furans were markedly increased as reaction temperature and time increased. The results showed that caramel-like and burnt sugar-like aroma produced by alanine -glucose reaction must be mainly comprised of nitrogeneous heterocyclic such as pyrazines, pyrroles and oxygen heterocyclic compounds such as 2-hydroxy-3-methyl-2-cyclopenten-1-one and 2,5-dimethyl-4-hydroxy-3(2H)-furanone.

• Korean Chemical Engineering Research
• /
• v.50 no.2
• /
• pp.353-357
• /
• 2012

The new qualitative and quantitative analytical method for hydrocarbon compounds in DME-LPG blending fuel, mixing dimethyl ether (DME) with liquefied petroleum gas (LPG), by using gas chromatography (GC) was investigated. It is difficult to analyze all components of DME-LPG blending fuel by using single column in GC due to consisting of the non-polar LPG and the polar DME which is oxygen-containing compound. Therefore, it has been introduced the Deans switching system, which are useful for analyzing mixtures of a very different nature and/or target analytes in very complex matrix. This technique is to control the pressure between two columns and to selectively change the path of effluent flows to either one of two columns. As a result, we found that DME and LPG can be completely separated at the different columns and the determination of all hydrocarbon compounds in DME-LPG blending fuel can be achieved to this method qualitatively and quantitatively during the operation of one injection. In addition, this method can be applied to the determination of trace components of by-product, such as methanol, methyl formate and ethyl methyl ether, which will be derived from DME synthesis process.

• The Korean Journal of Food And Nutrition
• /
• v.17 no.3
• /
• pp.313-321
• /
• 2004

Separation-concentration of sulfur containing heterocyclic compounds(SCHC) from many reaction meat flavors manufactured with Maillard reaction was carried out. Profile of SCHC was identified and analyzed by GC and GC-MSD. The results were as follows. 1. Profile of SCHC could be identified 7 kinds thiazole and 11 kinds thiophene, the major produced compounds were thiophene, thiazolidine, 4-methyl-5-thiazole ethanol. 2. In the case of SCHC, relationship between changes of reaction conditions and the kind of produced components were as same, but produced amounts appeared the difference. Producing amount of complexed SCHC and caramellike note as well as oxygen containing heterocyclic compounds were high level more than high reaction temperature and long time reaction period. 3. Producing ratio of comparative simple structural SCHC were the highest level at reaction conditions of moisture content 50%, reaction temperature 100$^{\circ}C$ and reaction time 2 hours. Reaction conditions for the revelation of reaction meat flavor were below 110$^{\circ}C$ and less than 2 hours. 4. Relationship between moisture content and reaction temperature as well as reaction time had very relative relation. From the change of moisture content and reaction conditions could be obtained the simultaneously profile. Signal presentation for production of reaction meat flavor could be from extraction-separation-concentration of SCHC through simplification of raw-materials in the flavor and seasoning food industry.

• Journal of Energy Engineering
• /
• v.15 no.1 s.45
• /
• pp.52-59
• /
• 2006

This paper examined the conversion of methane to hydrogen and other higher hydrocarbons using dielectric barrier discharge with AC pulse power. Two metal electrodes of a coaxial-type plasma reactor were separated by gas gap and an alumina tube. The inner electrode was located inside the alumina tube. The alumina tube was located inside the stainless steel tube, which was used as the outer electrode. Effect of feed gas composition (methane, oxygen, argon, water and helium), flow rate, applied frequency, input volt-age on methane conversion and product distribution were studied. The major products of plasma chemical reactions were ethylene, ethane, propane, buthane, hydrogen, carbon monoxide and carbon dioxide. The increment of applied voltage and the usage of inert gas as the background (helium and argon) enhanced the selectivity of hydrocarbons and methane conversion. The addition of water in the feed stream enhanced the conversion of methane and yield of hydrogen. Higher voltage leads to higher yield of $C_2H_6,\;C_3H_8,\;C_4H_{10}$ and yield or $C_2H_2\;and\;C_2H_4$ appeared highly in lower voltage.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2016.11a
• /
• pp.164-164
• /
• 2016

항만 및 해양 구조물은 육상과는 비교할 수 없을 정도로 가혹한 해수 환경에서 사용되며 계속적으로 부식 손상을 받는다. 따라서 강구조물이 장기적으로 안전하게 사용되기 위해서는 적절한 방식은 물론 철저한 유지관리가 필수적이다. 한편, 현재 해양환경 중 항만, 조선, 해양산업 등에 많이 이용되는 강구조물은 이에 대응하기 위하여 일반적으로 도장방식이나 음극방식이 사용되고 있다. 음극방식은 피방식체를 일정전위로 음극 분극하는 원리로써 외부전원을 인가하거나 비전위의 금속을 희생양극으로 연결하여 방식하는 방법이다. 이와같이 해수 중 음극방식을 실시할 경우 해수 중 용존하는 많은 이온들 중에서 특히 $Ca^{2+}$ 이나 $Mg^{2+}$ 이온이 탄산칼슘, 수산화마그네슘을 주성분으로하는 화합물로 형성된다. 이렇게 생성된 전착막은 산소 확산을 방지하는 물리적 장벽을 형성하고 부식율을 감소시키는 것으로 보고되고 있다. 그러나 전착막은 소지 금속과의 결합력이 불균일 함은 물론 막을 형성하는데 있어서 장시간이 소요된다는 단점이 있다. 따라서 본 연구에서는 해수 중 음극방식 응용 원리에 의해 전착막을 형성하고, 석출속도, 밀착성 및 내식특성을 향상시키기 위해 해수 중 기체를 용해시켜 제작한 막의 특성을 분석-평가하였다. 본 연구에 사용된 기판(substrate)은 일반구조용 강(SS400)을 사용하였으며, 면적은 $70mm{\times}30mm$, 두께는 1 mm로 제작하여 실험을 진행하였다. 외부전원은 정류기(Rectifier, xantrex, XDL 35-5T)를 사용하여 3 및 $5A/m^2$ 의 조건으로 인가하였고, 양극은 Carbon Rod를 사용하였다. 이때 해수에 주입한 이산화탄소의 양은 0.5 NL/min 였다. 각 조건별로 제작된 전착막에 대해 외관관찰, 석출량, 모폴로지, 조성원소 및 결정구조 분석을 실시하였고, 밀착성 및 내식특성을 평가하기 위해 테이핑 테스트(Taping Test, JIS K 5600-5-6)와 3.5 % NaCl 용액에서 전기화학적 양극 분극 시험을 진행하였다. 시간에 따른 전착막의 외관관찰 결과 전류밀도의 증가와 함께 상대적으로 많은 피막이 형성되었고, 용해시킨 기체에 의해 더 치밀하고 두터운 피막이 형성됨을 확인할 수 있었다. 성분 및 결정구조 분석 결과 $Mg(OH)_2$ 성분의 Brucite 및 $CaCO_3$ 성분의 Calcite 구조 및 Aragonite 구조를 확인하였으며, 용해시킨 기체의 영향으로 $CaCO_3$ 성분의 Aragonite 구조가 상대적으로 많이 검출되었다. 이는 해수 중 용해된 이산화탄소의 영향으로 인해 풍부한 ${CO_3}^{2-}$ 이온이 형성되고 용액 pH를 낮게 유지시켜 Ca 화합물 형성이 용이한 환경이 조성되는 것으로 판단된다. 밀착성 및 내식성 평가를 실시한 결과 해수중 용해시킨 기체에 의해 제작한 시편의 경우 견고하고 화학적 친화력이 높은 Aragonite 결정이 표면을 치밀하게 덮어 전해질로부터 산소와 물의 침입을 차단하는 역할을 하여 기체를 용해시키지 않은 $3A/m^2$ 및 $5A/m^2$ 보다 비교적 우수한 밀착성 및 내식 특성을 보이는 것으로 사료된다.

• Applied Chemistry for Engineering
• /
• v.24 no.4
• /
• pp.433-437
• /
• 2013

Electrical discharge plasma created in a multi-channel porous ceramic membrane-supported catalyst was applied to the decomposition of a volatile organic compound (VOC). For the purpose of improving the oxidation capability, the ceramic membrane used as a low-pressure drop catalyst support was loaded with zinc oxide photocatalyst by the incipient wetness impregnation method. Alternating current-driven discharge plasma was created inside the porous ceramic membrane to produce reactive species such as radicals, ozone, ions and excited molecules available for the decomposition of VOC. As the voltage supplied to the reactor increased, the plasma discharge gradually propagated in the radial direction, creating an uniform plasma in the entire ceramic membrane above a certain voltage. Ethylene was used as a model VOC. The ethylene decomposition efficiency was examined with experimental variables such as the specific energy density, inlet ethylene concentration and zinc oxide loading. When compared at the identical energy density, the decomposition efficiency obtained with the zinc oxide-loaded ceramic membrane was substantially higher than that of the bare membrane case. Both nitrogen and oxygen played an important role in initiating the decomposition of ethylene. The rate of the decomposition is governed by the quantity of reactive species generated by the plasma, and a strong dependence of the decomposition efficiency on the initial concentration was observed.

• Journal of the Korean Chemical Society
• /
• v.41 no.5
• /
• pp.234-238
• /
• 1997

The photochemical reaction of ammonia in deoxygenated aqueous methanol has been investigated at 25$^{\circ}C$ using 184.9 nm UV light. Amination was carried out by irradiating the solution of reaction mixture, and the formation of methoxyamine, hexamine, 1,1-dimethylhydrazine, dimethylamine, formamide, and a small amount of ethylenediamine was observed. In addition to these, carbonyl compounds such as formaldehyde, ethyleneglycol, glyoxal, and hydrazine were also produced. The initial quantum yields of the products were determined and probable mechanisms for the photochemical reaction were presented on the basis of product analysis.