• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 추계학술대회 논문집
• /
• pp.321-324
• /
• 2009

Upgrading of pyrolysis wax oil has been conducted in a continuous fixed bed reactor at $450^{\circ}C$, 1hour, LHSV 3.5/h. The catalytic degradation using HZSM-5 catalyst are compared with the thermal degradation and also was studied with a function of experimental variables. The raw pyrolysis wax oil shows relatively high boiling point distribution ranging from around $300^{\circ}C$ to $550^{\circ}C$, which has considerably higher boiling point distribution than that of commercial diesel. The product characteristic from thermal degradation shows a similar trend with that of raw pyrolysis wax oil. This means the thermal degradation of pyrolysis wax oil at high degradation temperature is not sufficiently occurred. On the other hand, the catalytic degradation using HZSM-5 catalyst relative to the thermal degradation shows the high conversion of pyrolysis wax oil to light hydrocarbons. This liquid product shows high gasoline range fraction as around 90% fraction and considerably high aromatic fraction in liquid product. Also, in the catalytic degradation the experimental variable such as catalyst amount and reaction temperature was studied.

• Journal of Electrical Engineering and Technology
• /
• 제12권2호
• /
• pp.840-845
• /
• 2017

In this paper, in order to investigate the lifetime of oil-paper insulation, specimens were artificially aged with thermal and electrical multiple stresses. Accelerated ageing factors and equivalent operating years for each aging temperatures were derived from results of tensile strengths for the aged paper specimens. Also, the evaluation for the multi-stress aged specimens were carried out through the measurement of impulse breakdown voltage at high temperature of $85^{\circ}C$. The lifetimes of the oil-paper insulations were calculated with the value of 66.7 for 1.0 mm thickness specimens and 69.7 for 1.25 mm thickness specimens throughout the analysis of impulse BD voltages using equivalent operating years, which means that dielectric strengths would not be severely decreased until the mechanical lifetime limit. Therefore, for the lifetime evaluation of the oil-paper insulation, thermal aging would be considered as a dominant factor whereas electrical degradation would be less effective.

• 전기학회논문지
• /
• 제65권10호
• /
• pp.1688-1693
• /
• 2016

In this study shall investigate the influence upon the electrical property of transformer oil due to the heat among accelerated heat degradation experiment for a constant hour in the typical insulation oils of mineral base oil, silicon base oil and vegetable oil. In addition, the electric insulation performance of insulation materials in transformer shall be evaluated through the electric property analysis according to the heat degradation of epoxy insulation material, which has been used for electric facilities such as a molded transformer.

• 청정기술
• /
• 제15권3호
• /
• pp.186-193
• /
• 2009

본 연구에서는 상용운전 중에 있는 반연속식 로터리 킬른형 열분해반응기에 지자체에서 발생되는 필름형 혼합 폐플라스틱을 투입한 후 열분해하여 얻은 저급의 열분해유를 세 형태의 반응온도 프로그램에서 분해반응시키고, 여기에서 얻어지는 생성유의 특성을 논의하였다. 원료인 저급 열분해유의 특성은 원소분석 및 발열량 분석, SIMDIST 분석으로 확인하였고, 각 반응온도 프로그램에 따른 분해반응 결과는 각 성분의 수율분포, 액상 생성물의 누적수율과 생성비 등으로 논의하였다. 연구결과는 한 단계 반응온도 프로그램에 비해 다단계 반응온도 프로그램의 경우가 원하는 생성물인 오일수율이 높았고, 상대적으로 잔류물의 수율은 낮게 나타났다. 연속적인 열분해반응에서 반응온도 프로그램은 생성물의 수율분포 등 생성유 특성에 많은 영향을 주었다.

• Food Science and Biotechnology
• /
• 제16권6호
• /
• pp.981-987
• /
• 2007

Effects of lignan compounds (sesamol, sesamin, and sesamolin) extracted from roasted sesame oil on the autoxidation at $60^{\circ}C$ for 7 days and thermal oxidation at $180^{\circ}C$ for 10 hr of sunflower oil were studied by determining conjugated dienoic acid (CDA) contents, p-anisidine values (PAV), and fatty acid composition. Contents of lignan compounds during the oxidations were also monitored. ${\alpha}$-Tocopherol was used as a reference antioxidant. Addition of lignan compounds decreased CDA contents and PAY of the oils during oxidation at $60^{\circ}C$ or heating at $180^{\circ}C$, which indicated that sesame oil lignans lowered the autoxidation and thermal oxidation of sunflower oil. Sesamol was the most effective in decreasing CDA formation and hydroperoxide decomposition in the auto- and thermo-oxidation of oil, and its antioxidant activity was significantly higher than that of ${\alpha}$-tocopherol. Sesamol, sesamin, and sesamolin added to sunflower oil were degraded during the oxidations of oils, with the fastest degradation of sesamol. Degradation of sesamin and sesamolin during the oxidations of the oil were lower than that of ${\alpha}$-tocopherol. The results strongly indicate that the oxidative stability of sunflower oil can be improved by the addition of sesamol, sesamin, or sesamolin extracted from roasted sesame oil.

• 전기학회논문지
• /
• 제56권9호
• /
• pp.1561-1565
• /
• 2007

According to thermal degradation on power transformers, it is known that electrical, mechanical and chemical characteristics for power transformer's oil-paper are changed. In the chemical property, especially, when the kraft paper is aged, the cellulose polymer chains break down into shorter lengths. It causes decrease in both tensile strength and degree of polymerization of paper insulation. Also the paper breakdown is accompanied by an increase in the content of various furanic compounds within the dielectric liquid. It is known that furanic components in transformer oil come only from the decomposition of insulating paper rather than from the oil itself. Therefore the analysis of furanic degradation products provides a complementary technique to dissolved gas analysis for monitoring transformers when we evaluate the aging of insulating paper by the total concentration of carbon monoxide and carbon dioxide dissolved in oil only. Recently, the analysis of furanic compounds by high performance liquid chromatography(HPLC) using IEC 61198 method for estimating degradation of paper insulation in power transformers has been used more conveniently for assessment of oil-paper. It is know that the main products which is produced by aging are 2-furfuryl alcohol, 2-furaldehyde(furfural), 2-furoic acid, 2-acetylfuran, 5-methyl-2-furaldehyde, and 5-hydroxymethyl-2-furaldehyde. For investigating the accelerated aging process of oil-paper samples we manufactured accelerating aging equipment and we estimated variation of insulations at $140^{\circ}C$ temp. during 500 hours. Typical transformer proportions of copper, silicon steel and iron have been added to oil-paper insulation during the aging process. The oil-paper insulation samples have been measured at intervals of 100 hours. Finally we have analyzed that 2-furoic acid and 2-acetylfuran products of furanic compounds were detected by HPLC, and their concentrations were increased with accelerated aging time.

• 환경위생공학
• /
• 제15권4호
• /
• pp.98-104
• /
• 2000

Commercial rubber(IR, NR, BR), SBR, and tire were degraded by thermal degradation process. The oil yield of rubbers and tire ranges about 37~86%, it was increased with increase of operation temperature in pyrolysis. And the yield of pyrolytic oil was increased with increase of heating rate. The maximum oil yields of IR, NR, BR, SBR, and tire were 80, 73, 83, 86 and 55% each at $700^{\circ}C$ with a heating rate of $20^{\circ}C$/min, respectively. The pyrolytic oil components were consisted of about 50 aromatic compounds. The calorific value of purolytic oil of commercial rubber, SBR, and tire was measured by calorimeter, it was 39~40 kJ/g. The BET surface area of pyroblack was $47~63m^2/g$. The optimum condition of pyrolysis was operating temperature of $700^{\circ}C$ with heating rate of $20^{\circ}C$. Therefore, the pyrolytic oil and pyroblack are possible to alternative fuel and carbon black.

• Tribology and Lubricants
• /
• 제24권1호
• /
• pp.7-13
• /
• 2008

In this work, a simple and low cost sensor technique is proposed to test oil color in real time using in-line sensor. It is presented to use a ratio of intensity in red wavelength range to intensities of green and blue wavelength ranges (defined as a 'chromatic ratio') in order to estimate the oil color change. The proposed sensor technique is realized by irradiating a white LED as light source and a RGB color sensor as photoreceiver, and the chromatic ratio of various types of used oils are measured. The results show that chromatic ratio generally reflects chemical deterioration of oil, including oil oxidation and thermal degradation. It is concluded that the proposed sensor could be used for an effective oil monitoring technology.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
• /
• pp.159-163
• /
• 1989

The various degradation phenomena, such as the evolution of gases, tan $\delta$, moisture content and total acid number in power transformer insulation oil, have been measured and analyzed. Mineral oil has been degraded at laboratory by the forced thermal stress of $60^{\circ}C$ and $90^{\circ}C$ respectively. Thermal aging oil has been degraded about 17, 34, 72 days. Also, we extracted insulation oil from working transformers. We measured gases dissolved in samples, tan $\delta$, moisture content, total acid number. Activation energy and resistivity is calculated from them. It is found that gases and tan $\delta$ increases as partial discharge and total acid number increases and that conductivity of the sample increases as activation energy increases.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
• /
• pp.574-574
• /
• 2005

To found out the degradation characteristic of transformer insulation, insulation material was depisited into transformer oil and heated. Due to the thermal stress which added to insulation, the density of carbon dioxide which included in transformer oil was mesured by using the gas density detection equipment of gas sensor and air circulation method. As a result, it didn't match with the transformer supervision standard. But it was found that as thermal stress increased, the density of carbon dioxide propertionally increased.