• Journal of the Korean Society of Mineral and Energy Resources Engineers
• /
• v.55 no.6
• /
• pp.660-669
• /
• 2018

Enhanced oil recovery (EOR) is a method used to improve the recovery factor of remaining hydrocarbon in reservoir. Polymer and surfactant EOR techniques have limitations depending on reservoir or production conditions (temperature, salinity, etc.) because the polymer and surfactant are highly affected by the reservoir conditions. In this study, analysis of the current improvements to chemical substances and application technologies was performed based on recent research data. Conventional polymer is readily degraded by the conditions of high temperature and high salinity. Therefore, new polymers and injection techniques have been developed to remediate such problems. In addition, surfactant applicable to shale and carbonate reservoirs is developed as petroleum recovery expands to unconventional reservoirs. However, these chemical substances are not widely used in the current oil fields due to high costs. Therefore, further studies must be conducted to reduce the cost and thus increase the effectiveness of EOR techniques.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.36 no.4
• /
• pp.408-412
• /
• 2023

In this paper, in order to analyze high electrical insulation and cooling performance using mineral oil, the liquid insulating oil was changed in electrode shape and distance between electrodes to compare and analyze electrical characteristics according to equal electric field, quasi-equivalent electric field, and unequal electric field. As a result, the breakdown voltages were 36,875 V and 36,875 V in the form of sphere-sphere and plate-plate electrodes with equal electric fields. The breakdown voltage was 31,475 V in the sphere-plate electrode type, which is a quasi-equilibrium field, and the breakdown voltage was 28,592 V, 27,050 V, and 22,750 V in the needle-needle, sphere-needle, and needle-plate electrode types, which are unequal fields. Through this, it is possible to know the difference in breakdown voltage according to the type of electric field. The more equal the field, the higher the breakdown voltage, and the more unequal field, the lower the breakdown voltage. The difference in insulation breakdown voltage could be seen depending on the type of electric field, the insulation breakdown voltage was higher for the more equal electric field, and the insulation breakdown voltage was lower for the more unequal electric field. Also, it was confirmed that the closer the distance between the electrodes, the higher the insulation breakdown voltage, the higher the insulation breakdown current, and the insulation breakdown voltage and the insulation breakdown current were proportional.

• KSTLE International Journal
• /
• v.8 no.1
• /
• pp.1-6
• /
• 2007

Chromatic device was developed using light emitting diodes, optic fibers and photodiodes. Chromatic ratio and total contamination parameters based on transmitted light intensity in Red, Green, and Blue wavelengths were used for oil chemical and particulate contamination assessment. Chromatic ratio criterion was found independent of the particulate contamination of oil; but depended on chemical degradation, being more sensitive for synthetic than mineral hydraulic oil. Total contamination index of the sensor depended on both the chemical degradation and particulate contamination of the oil; being most sensitive in blue wavelength, and least in the red. Test results for synthetic hydraulic oils monitored corroborated with results of other tests such as viscosity, total acid number, elemental optical emission spectroscopy, particulate counts and UV-VIS photospectrometry. Chromatic ratio showed a clearer indication of oil degradation, compared to key monitoring parameters such as total acid number, viscosity and particle counts. The results showed that these parameters are effective criteria for the condition monitoring of synthetic hydraulic oils.

• Tribology and Lubricants
• /
• v.34 no.4
• /
• pp.160-167
• /
• 2018

Vegetable oils can contribute to the goal of energy independence and security owing to their naturally renewable resources. One of the representative vegetable oils is biodiesel, which is being used in domestic and European markets as a blended fuel with automotive diesel. Vegetable oils are promising candidates as base fluids to replace petroleum lubricants because of their excellent lubricity and biodegradability. We prepared biodiesel with a purity of 99.9% via the esterification of waste cooking oil. Blended biodiesel and Petro-lube base oil were mixed to produce five types of mixed lubricating oil. We analyzed the various characteristics of the blended biodiesel with Petro-lube base oil for different blending ratios. The lubricity of the vegetable lubricant improves as the content of biodiesel increases. In addition, since zinc dialkyldithiophosphates (ZnDTPs) are widely used as multifunctional additives in petroleum-based lubricants, we optimized the blending ratio for lubricity, oxidation stability, and shear stability by adding ZnDTP as a performance additive to improve the biodiesel properties, such as oxidation stability and hydrolysis. The optimized lubricants improve by approximately 25% in lubricity and by 20 times in oxidation stability and shear stability after the addition of ZnDTP.

• Journal of Energy Engineering
• /
• v.22 no.2
• /
• pp.136-140
• /
• 2013

The stringent emission norms cannot be met through engine design and exhaust after treatment alone. Use of oxygenated fuel like biodiesel as a alternative to diesel may be the best way to reduce emissions today. In this study, Diesel fuel and pure biodiesel (mahua oil) were tested on a single cylinder naturally-aspirated direct-injection diesel engine. The study aims to investigate the effects of the mahua oil biodiesel on existing diesel engine emissions. The effect of test fuels on engine emissions like CO, HC, $CO_2$, NOx and smoke emissions was investigated with respect to the load on engine. Smoke opacity of Diesel engine was lower in case of biodiesel of mahua oil as compare to mineral diesel. NOx emissions was little higher during the whole range of loading, which is a typical characteristic of biodiesel. However the increments are within in the narrow range. $CO_2$ emissions was bit higher which is the indication of better combustion due to presence of rich oxygen in the mixture, it results in the low values of CO and HC during the whole range of experiments. Thus considering environmental norms most of the engine emissions, it can be concluded and biodiesel derived from mahua oil could be used in a conventional diesel engine without any modification.

• Tuberculosis and Respiratory Diseases
• /
• v.68 no.6
• /
• pp.354-357
• /
• 2010

Exogenous lipid pneumonia is a rare disease resulting from the aspiration or inhalation of vegetable, animal, or mineral oils. In Korea, the most frequently implicated agent is squalen, which can be obtained from shark liver oil. Lipid pneumonia by aspiration of the vegetable oil is very rare. We experienced a 77-year-old man with a history of ingestion of green perilla oil. His clinical course was favorable; after exposure to the oil was stopped, the patient's symptoms improved.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.24 no.7
• /
• pp.938-944
• /
• 2000

Recently, micro fin tube is widely used to heat exchanger for high performance. And, as the alternative refrigerants for R-22, hydrocarbons such as R-290, R-600 and R-600a are very promising because of their low GWP and ODP. Thus, R-290 was used as working fluid in this study. Most design of heat exchanger had been based on heat transfer characteristics of pure refrigerant although refrigerant oil exists in the refrigeration cycles. So, the influence of oil on heat transfer characteristics have to be considered for investigating exact evaporation heat transfer characteristics. But, this is an unresolved problem of refrigeration heat transfer. Therefore the influence of the refrigeration oil to the evaporation heat transfer characteristics of R-290 were conducted in a horizontal micro tin tube. The mineral oil was used as refrigeration oil. The experimental apparatus consisted of a basic refrigeration cycle and a system for oil concentration measurement. Test conditions are as the follows; evaporation temperature $5^{\circ}C$, mass velocity 100 $kg/m^2s$, heat flux 10 $kW/m^2$, oil concentration 0, 1.3, 3.3, 5.7 wt.%, and quality $0.07{\sim}1.0$. When refrigeration oil was entered, oil foaming was observed at the low quality region. And, very small bubbles were observed as quality was increased. Pressure drop and heat transfer coefficient increased as the concentration of refrigeration oil increased to 5 wt.%.. The performance index of heat exchanger was the highest near 3.3 wt.%.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.43 no.2
• /
• pp.52-58
• /
• 2021

The article presents the results of the content of the chemical and biochemical composition of the pupa of the wild silkworm Saturnia pyri belonging to the family Saturniidae, species of Lepidoptera. The nutritional value of silkworm Saturnia pyri pupae was evaluated, which contained 51% dry matter, 52.50% crude protein, 27.89% fat, 10.50% chitin fibers, 2.5% ash and 27 macro- and microelements and 25 mg alpha tocopherols in 100 g oil. The X-ray fluorescence method was used to determine the content of mineral elements in the pupa of the silkworm Saturnia pyri. It was revealed that the pupa of this type of silkworm contains 25 elements, of which the relative amount of K, Mg, Na, Ca, Al is much higher than other elements.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.18 no.3
• /
• pp.254-261
• /
• 2006

The effect of enhanced geometry (pore diameter, gap width) is investigated on the pool boiling of R-123/oil mixture for the enhanced tubes having pores with connecting gaps. Tubes with different pore diameters (and corresponding gap widths) are specially made. Significant heat transfer degradation by oil is observed for the present enhanced tubes. At 5% oil concentration, the degradation is 26 to 49% for $T_{sat}=4.4^{\circ}C$. The degradation increases 50 to 67% for $T_{sat}=26.7^{\circ}C$. The heat transfer degradation is significant even with small amount of oil (20 to 38% degradation at 1% oil concentration for $T_{sat}=4.4^{\circ}C$), probably due to the accumulation of oil in sub-tunnels. The pore size (or gap width) has a significant effect on the heat transfer degradation. The maximum degradation is observed for $d_p$ = 0.20 mm tube at $T_{sat}=4.4^{\circ}C$, and for $d_p$=0.23 mm tube at $T_{sat}=26.7^{\circ}C$. The minimum degradation is observed for $d_p$=0.27 mm tube for both saturation temperatures. It appears that the oil removal is facilitated for the larger pore diameter (along with larger gap) tube. The highest heat transfer coefficient with oil is obtained for $d_p$ =0.23 mm tube, which yielded the highest heat transfer coefficient for pure R-123. The heat transfer degradation increases as the heat flux decreases.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.2 no.4
• /
• pp.291-296
• /
• 2014

For the purpose of energy consumption and green-house gas reduction from building, new insulation materials with improved thermal property have been developed and used. Among new insulation materials, mineral hydrate which compensates for the defects of existing materials is using as a prominent insulation material. The fabrication method of mineral hydrate is similar to that of ALC for building structure but mineral hydrate is only used for insulation. The raw materials that make up of mineral hydrate are cement, lime and anhydrite. Especially anhydrite is all dependant on imports. In this study, Desulfurization Gypsum(DG), by-product of oil plant, was used for replacing for imported anhydrite and waste recycling. DG substituted all of anhydrite and a part of lime. Mineral hydrate used DG had analogous thermal and physical properties, compared to existing mineral hydrate.