고체산 촉매를 이용해 합성한 diglycerol ester의 전기절연 특성 및 평가

권미성; 백재호; 김명환; 박대원; 이만식; Miseong Gwon; Jae Ho Baek; Myung Hwan Kim; Dae-Won Park; Man Sig Lee

Applied Chemistry for Engineering, Vol.25, No.3, 254-261, June, 2014

Export Citation

고체산 촉매를 이용해 합성한 diglycerol ester의 전기절연 특성 및 평가

Insulation Properties and Evaluation of Diglycerol Ester Synthesized by Solid Acid Catalysts

권미성^{1, 2}, 백재호¹, 김명환¹, 박대원 ², 이만식^{1, †}

¹한국생산기술연구원
²부산대학교 화공생명공학부

Miseong Gwon^{1, 2}, Jae Ho Baek¹, Myung Hwan Kim¹, Dae-Won Park², and Man Sig Lee^{1, †}

¹Korea Institute of Industrial Technology(KITECH), Cheonan-si 331-822, Republic of Korea
²Pusan National University, Busan 609-735, Republic of Korea

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초록

변압기 내부에서 발생한 열의 냉각과 절연의 목적으로 채워지는 전기절연유는 광유가 널리 이용되고 있지만, 유출 시 야기되는 환경오염 문제와 열적 불안정성 등의 문제가 있다. 친환경적이고 넓은 온도 범위에서 사용 가능한 전기절연유를 합성하기 위해, 디글리세롤과 두 종류의 지방산을 반응시켜 diglycerol ester를 합성하였다. 서로 다른 특성을 가진 올레산과 카프릴산의 몰비에 따른 절연특성을 분석한 결과, 지방산의 몰비가 Oleic acid:Caprylic acid = 1:3일 때 유동점은 .50 ℃, 인화점은 306 ℃로 가장 우수한 절연특성을 보였다. 또한, 합성물은 지방산의 전환율이 상승할수록 인화점은 상승하고 유동점은 감소하였다. SO42-/ZrO2의 소성온도에 따른 촉매특성 및 전환율을 살펴본 결과, 600 ℃에서 소성한 SO42-/ZrO2가 결정성을 가지면서 비표면적 당 산점의 밀도가 높아 가장 높은 전환율을 보였다. 합성한 diglycerol ester는 식물성 절연유와 비교했을 때 전반적으로 식물성 절연유보다 우수한 특성을 보였다.

The transformer is a static electrical device that transfers energy by inductive coupling. Then, heat is occurred at coils, inner transformer was filled with insulating oils for cooling and insulation. Although mineral oil as insulating oil has been widely used, it does not meet health and current environmental laws because it is not biodegradable. Therefore, in this study, the diglycerol ester was synthesized with diglycerol and fatty acids (oleic acid and caprylic acid) over various catalysts for insulating oil having biodegradability, high flash points and low pour points. The sulfated zirconia (SO42-/ZrO2) catalyst prepared at different calcination temperature shows the highest conversion of fatty acids at 600 ℃ due to crystallinity and high density of acid sites per surface area. When the molar ratio of oleic acid and caprylic acid is 1:3, the diglycerol ester shows superior insulation properties that are the flash point of 306 ℃ and pour point of -50 ℃. The insulation properties of synthesized diglycerol ester shows the pour point of -50 ℃ and the flash point of over 300 ℃. Therefore, diglycerol ester is superior to the vegetable oils in insulation properties.

Keywords:diglycerol ester;fatty acid;insulating oil;esterification;solid acid catalysts

[References]

Fofana I, Wasserberg V, Borsi H, Gockenbach E, Challenge of mixed insulating liquids for use in high-voltage transformers. II. Investigations of mixed liquid impregnated paper insulation, IEEE Electrical Insulation Magazine, 18, 5-16 (2002)
Fernandez I, Ortiz A, Delgado F, Renedo C, Perez S., Comparative evaluation of alternative fluids for power transformers, Electric Power Systems Research, 98, 58-69 (2013)
McShane CP, Corkran JL, Harthun RA, Gauger GA, Rapp KJ, Vegetable oil based dielectric fluid, US Patent 6,352,655 (2002)
Prevost TA, Dielectric Properties of Natural Esters and their Influence on Transformer Insulation System Design and Performance, Transmission and Distribution Conference and Exhibition, 30-34 (2006)
Rozga P, The influence of concentrated heat flux on dielectric properties of synthetic and natural esters, Power Modulator and High Voltage Conference (IPMHVC), 378-381 (2012)
한동희, 환경친화형 식물성 변압기 절연유 기술개발, Korea Electrotechnology Research Institute (2006)
Fernandez I, Ortiz A, Delgado F, Renedo C, Perez S, Comparative evaluation of alternative fluids for power transformers, Electric Power Systems Research, 98, 58-69 (2013)
Park HS, Kim JH, Lee HB, Problem considerations and wxpectations inapplying vegetable oil to power transformer, Proceedings of the ITFE Summer conference, 184-186 (2009)
Park JY, Kim DK, Lee JP, Park SC, Kim YJ, Lee JS, Bioresour. Technol., 99(5), 1196 (2008)
Augusta M, Martins G, Vegetable Oils, an Alternative to Mineral Oil for Power Transformers-Experimental Study of Paper Aging in Vegetable Oil Versus Mineral Oil, IEEE Electrical Insulation Magazine, 26, 7-13 (2010)
Lopez DE, Goodwin JG, Bruce DA, Furuta S, Appl. Catal. A: Gen., 339(1), 76 (2008)
Lam MK, Lee KT, Mohamed AR, Appl. Catal. B: Environ., 93(1-2), 134 (2009)
ZrO2 JCPDS No. 83-0944.
ZrO2 JCPDS No. 81-1545.
Heshmatpour F, Aghakhanpour RB, Adv. Powder Technol., 23(1), 80 (2012)
SnO2 JCPDS No. 41-1455.
SiO2 JCPDS No. 46-1045.
Reddy BM, Reddy GK, Rao KN, Katta L, J. Mol. Catal. A-Chem., 306(1-2), 62 (2009)
Han DH, Cho HG, Han SW, Ahn MS, Performance of environment friendly insulating dielectric oil for power transformer, KERI (2004)
Kotwal M, Deshpande SS, Srinivas D, Catal. Commun., 12, 1302 (2011)
Gwon MS, Ryu YB, Park DW, Lee MS, Materials Science Forum, 761, 3 (2013)

[Related Articles]

[1] Fofana I, Wasserberg V, Borsi H, Gockenbach E, Challenge of mixed insulating liquids for use in high-voltage transformers. II. Investigations of mixed liquid impregnated paper insulation, IEEE Electrical Insulation Magazine, 18, 5-16 (2002)

[2] Fernandez I, Ortiz A, Delgado F, Renedo C, Perez S., Comparative evaluation of alternative fluids for power transformers, Electric Power Systems Research, 98, 58-69 (2013)

[3] McShane CP, Corkran JL, Harthun RA, Gauger GA, Rapp KJ, Vegetable oil based dielectric fluid, US Patent 6,352,655 (2002)

[4] Prevost TA, Dielectric Properties of Natural Esters and their Influence on Transformer Insulation System Design and Performance, Transmission and Distribution Conference and Exhibition, 30-34 (2006)

[5] Rozga P, The influence of concentrated heat flux on dielectric properties of synthetic and natural esters, Power Modulator and High Voltage Conference (IPMHVC), 378-381 (2012)

[6] 한동희, 환경친화형 식물성 변압기 절연유 기술개발, Korea Electrotechnology Research Institute (2006)

[7] Fernandez I, Ortiz A, Delgado F, Renedo C, Perez S, Comparative evaluation of alternative fluids for power transformers, Electric Power Systems Research, 98, 58-69 (2013)

[8] Park HS, Kim JH, Lee HB, Problem considerations and wxpectations inapplying vegetable oil to power transformer, Proceedings of the ITFE Summer conference, 184-186 (2009)

[9] Park JY, Kim DK, Lee JP, Park SC, Kim YJ, Lee JS, Bioresour. Technol., 99(5), 1196 (2008)

[10] Augusta M, Martins G, Vegetable Oils, an Alternative to Mineral Oil for Power Transformers-Experimental Study of Paper Aging in Vegetable Oil Versus Mineral Oil, IEEE Electrical Insulation Magazine, 26, 7-13 (2010)

[11] Lopez DE, Goodwin JG, Bruce DA, Furuta S, Appl. Catal. A: Gen., 339(1), 76 (2008)

[12] Lam MK, Lee KT, Mohamed AR, Appl. Catal. B: Environ., 93(1-2), 134 (2009)

[13] ZrO2 JCPDS No. 83-0944.

[14] ZrO2 JCPDS No. 81-1545.

[15] Heshmatpour F, Aghakhanpour RB, Adv. Powder Technol., 23(1), 80 (2012)

[16] SnO2 JCPDS No. 41-1455.

[17] SiO2 JCPDS No. 46-1045.

[18] Reddy BM, Reddy GK, Rao KN, Katta L, J. Mol. Catal. A-Chem., 306(1-2), 62 (2009)

[19] Han DH, Cho HG, Han SW, Ahn MS, Performance of environment friendly insulating dielectric oil for power transformer, KERI (2004)

[20] Kotwal M, Deshpande SS, Srinivas D, Catal. Commun., 12, 1302 (2011)

[21] Gwon MS, Ryu YB, Park DW, Lee MS, Materials Science Forum, 761, 3 (2013)