• Journal of the Korean Society for Precision Engineering
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• v.19 no.7
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• pp.80-87
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• 2002

Liquefied petroleum gas (LPG) is used in spark ignition (SI) engines. Fuel injection rate of an injector is affected by fuel temperature and pressure in LPG liquid injection systems for either a multi-point-injection (MPI) or a direct injection (DI) engine. Even fuel injection conditions are varied, the air-fuel ratio should be accurately controlled to reduce exhaust emissions. In this study, a correction factor fur the fuel injection rate of an injector is derived from density ratio and pressure difference ratio. A compensation method of injected fuel amount is proposed for a fuel injection control system. The experimental results for the LPG liquid injection system in a SI engine show that this system works well fur a full range of engine speed and load condition, and the air-fuel ratio is accurately controlled by the proposed correction factor.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.1112-1120
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• 2017

Petroleum products are composed of various types of hydrocarbon compounds. Like other types of liquids, they presented the variation of density and volume according to temperature change. The method of measuring the density of petroleum products in a liquid phase is based on experimental data obtained mainly for each fractionally distilled petroleum product. In this study, the density and volume changes of kerosene and automotive diesel according to temperature change were measured and the property of change were analyzed. The conversion values were calculated using the density volume conversion table proposed by international standard ASTM. In addition, we analyzed the differences between the reference values and the measured values for the temperature changes specified in the domestic metering law.

• Journal of the Korean Chemical Society
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• v.29 no.5
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• pp.496-502
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• 1985

The solvent extraction and cleanup processes for the simultaneous gas-liquid cliromatographic determination of 16 kinds of organochlorine pesticide residues were investigated. The pesticides were extracted out from-various crops with the aqueous acetone solution acidified (pH < 1.5) by adding conc. $H_3PO_4$. Most of the pesticides were partitioned from the solution with petroleum ether. Evaporated the extracting solvent, the residues were dissolved in ethylether-petroleum ether (6 : 94) eluent and eluted through the Florisil column activated at 650$^{\circ}$C for 2.5hrs. The extraction efficiency was over 94% and impurities were effectively removed by the column chromatography.

• Journal of the Korean Chemical Society
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• v.30 no.5
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• pp.465-474
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• 1986

The solvent extraction and cleanup processes for the simultaneous gas-liquid chromatographic determination of 11 kinds of organophosphorous pesticide residues in crops were investigated. The extracts dissolved with acetone were partitioned with petroleum ether after adding saturated NaCl solution. Evaporated the partitioning solvent, the residue was dissolved in methylene chloride and eluted through mixed adsorbent (1 : 2 : 4 of activated carbon, magnesia and diatomaceous earth) with methylene chloride as an eluent. The pesticides recovered were 82∼105% and the impurities were effectively removed.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.2
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• pp.223-233
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• 2020

Fast pyrolysis is one of the most promising technologies for converting biomass to liquid fuels. Pyrolysis bio-oil can replace petroleum-based fuels used in various thermal conversion devices. However, pyrolysis bio-oil is completely different from petroleum fuels. Therefore, in order to successfully use pyrolysis bio-oil, it is necessary to understand the fuel characteristics of pyrolysis bio-oil. This paper focuses on fuel characteristics and upgrading methods of pyrolysis bio-oil and discusses how these fuel characteristics can be applied to the use of pyrolysis bio-oils. In addition, the fuel quality standards of fast pyrolysis bio-oil were examined.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.9
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• pp.1-9
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• 1999

Liquid Petroleum Gas (LPG) has been widely used for commercial light-duty vehicles worldwide. Since LPG has a higher octane number and a lower maximum combustion temperature than gasoline , it becomes more popular fuel for reducing exhaust emissions. In tihs study, mathematical models of air intake and fuel delivery system are presented, and a PI-controller is designed for air-fuel ratio control. Hardware and software of an engine control module (ECM) are designed for an LPG engine. The ECM is built using a Motorola MC68HC05. In order to control the air-fuel ratio at stoichiometry, the PI-control algorithm is implemented in the ECM. The experiment results show the proto LPG ECM and its control scheme perform well to meet the stoichiometric air-duel ratio requirement.

• Korean Journal of Pharmacognosy
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• v.18 no.3
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• pp.184-187
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• 1987

Fatty acids and sterols were isolated from petroleum ether extract of seeds of Acanthopanax sessiliflorum Seeman. Fatty acids were obtained from the saponified fraction and sterols from nonsaponified fraction of petroleum ether extract. Fatty acids were identified by gas liquid chromatography, and its composition was myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid. The composition of sterols were determined by preparative TLC and gas liquid chromatography. It was confirmed to be a mixture of stigmasterol and ${\beta}-sitosterol$. These fatty acids and sterols were not previously reported from seeds of Acanthopanax sessiliflorum Seemann.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2809-2818
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• 2022

In this investigation work, liquid-liquid extraction (L.L.E) through three distinctive frameworks have been examined for assurance of slip velocity (S.V), and characteristic velocity (C.V) in a non-center rotating column (N.C.R.C) with a wide extend of factors. Three double frameworks with distinctive interfacial tension comprising of toluene-water (high interfacial tension), n-butyl acetate-water (medium interfacial tension), and n-butanol-water (low interfacial tension) were investigated for tests. Two common relationships for the expectation of S.V and C.V, including phase stream rates, rotor speed, column geometry additionally physical properties, are displayed. The recommended relationships were compared with test information gotten from the writing and the display examination. Findings of this study, the present proposed correlations are more accurate than those previously reported.

• Journal of ILASS-Korea
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• v.15 no.1
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• pp.38-43
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• 2010

The LPG(Liquefied Petroleum Gas) fuel attracts attention as a clean alternative fuel. In order to further reduce the exhaust emission and improve performance in LPG engines, the LPLi(Liquid Phase LPG Injection) system is used. In LPLi system, the fuel pump performance is important for keeping the LPG over it's saturated vapor pressure. An external fuel pump is needed to improve the durability for LPG engines. This paper predicted the variation of fuel properties on the LPLi system with an external fuel pump. From each component's thermodynamic model, an 1-D simulation is developed for LPLi system with an external fuel pump. Then the 1-D simulation data analyzed and compared with the rig-test. The 1-D simulation and the rig-test produced similar results.

• Polymer(Korea)
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• v.27 no.1
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• pp.84-89
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• 2003

Pyrolysis of high density polyethylene(HDPE) was carried out to find the effects of temperature and time on the pyrolysis. The starting temperature and activation energy of HDPE pyrolysis increased with increasing heating rate. In general, conversion and liquid yield continuously increased with pyrolysis temperature and pyrolysis time. This tendency is very sensitive with pyrolysis time, especially at 45$0^{\circ}C$. Pyrolysis temperature has more influence on the conversion than pyrolysis time. Each liquid product formed during pyrolysis was classified into gasoline, kerosene, light oil and wax 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 HDPE pyrolysis at 45$0^{\circ}C$ was in the order of light oil > wax > kerosene > gasoline, and at 475$^{\circ}C$ and 50$0^{\circ}C$, it was wax > light > oil > kerosene > gasoline.