• Journal of the Korean Institute of Gas
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• v.25 no.6
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• pp.80-84
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• 2021

As the Hydrogen law was enacted, 4 types of hydrogen appliances were designated as inspection products. The types of hydrogen appliances are water electrolysis equipment, hydrogen extraction equipment, stationary fuel cells, and mobile fuel cells. The establishment fo safety standards for hydrogen appliance inspection defines risk factors for each hydrogen appliance and stipulates safety standards to prevent risk factors. The main safety standards for each hydrogen appliance are hydrogen quality and safety control for water electrolysis, toxic substances emission prevention and carbon monoxide emission prevention for hydrogen extraction facilities, vibration safety for mobile fuel cells.

• 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 hydrogen and new energy society
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• v.33 no.4
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• pp.284-292
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• 2022

Hydrogen is promising a candidate for energy supporting the carbon neutrality policy for greenhouse gas reduction, which is being promoted in several countries, including Korea. Although challenging efforts-such as lowering the costs of green hydrogen production and fuel cells-remain, hydrogen fuel cell electric vehicles (FCEVs) are expected to play a significant role in the energy transition from fossil fuels to renewable energy. In line with this objective, the hydrogen FCEV working group in the International Organization for Standardization (ISO) compiled and revised international standards related to hydrogen refueling stations as of 2019. A well-established hydrogen quality management system based on the standard documents will increase the reliability of hydrogen charging stations and accelerate the use of FCEVs. In this study, among the published ISO standards and other references, the main requirements for managing charging stations and developing related techniques were summarized and explained. To respond preemptively to the growing FCEV market, a continuous hydrogen quality monitoring method suitable for use at hydrogen charging stations was proposed.

• Transactions of the Korean hydrogen and new energy society
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• v.17 no.4
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• pp.454-460
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• 2006

In the production of hydrogen from various sources like cracking of LPG, LNG, Crude oil, or alkaline water electrolysis, the things that we keep in mind is the entrapment of unexpected impurities in the stream of produced $H_2$. If it is true that we are not able to produce 100% pure $H_2$, then subsequent procedure is the elimination of the impurities and the determination of the concentrations of each constituents in $H_2$ stream. By the way, each country has different constituents in its fuels and unavoidablely it was cost/economy debates between coutries. Thus, in this paper, our goal is to provide current international issues for hydrogen production.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.3
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• pp.245-255
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• 2016

Commercial production line of FCEV was built in 2013 by Hyundai and followed by Toyota in 2014, with additional manufacturers planning to enter the market around 2017. Now there is limited hydrogen infrastructure over the world, but more hydrogen stations are planned, particularly in Japan, Korea, Germany, UK and USA. ISO TC 197 which was created in 1990 focused standardization in the field of systems and devices for the production, storage, transport, measurement and use of hydrogen. Total number of published ISO standards related to the TC and its SCs (number includes updates) is 17. Now there are 20 participating countries and 13 observing countries. The current status of activity of ISO TC197 was reviewed and particularly issues on hydrogen quality and hydrogen refueling station were discussed.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.12
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• pp.1371-1380
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• 2007

Study on the instability of waste plastic's thermal pyrolysis oil was carried out for the purpose of improving its quality. The reaction of pyrolysis oil with ozone changed double bonds into aldehydes and ketone, estimated that HDPE pyrolysis oil contained $\sim45$ wt% 1-alkene type olefins, and PP pyrolysis oil did $\sim73$ wt% olefins, which consisted of $\sim47$ wt% secondary and $\sim20$ wt% primary alkenes. The dark brown color and odor of pyrolysis oil were improved by eliminating double bonds, indicated that they were directly related to unsaturated hydrocarbons. Container test showed that metal can affected oil quality worse than the brown glass bottle. Antioxidant added into pyrolysis oil was consumed up to 90% within $2\sim3$ days and the wt. composition of unsaturated hydrocarbons in pyrolysis oil was not changed within 50 days, inferring that instability of pyrolysis oil due to unsaturated bonds can be stabilized by antioxidants. Adsorption test on silica gel, activated carbon and alumina to remove precipitates in oil produced a good result, but not enough to remove moisture. However, cheap anhydrous sodium carbonate showed the best removal efficiency of moisture as well as precipitates in oil. Therefore the pyrolysis oil quality improvement was accomplished by applying anhydrous $Na_2CO_3$ into the production plant.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.182-183
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• 2012

Organic light emitting diode (OLED) 나 organic photovoltaic device (OPV)와 같은 유기소자에 전극으로 쓰이고 있는 indium tin oxide (ITO) 박막의 품질을 향상시키기 위해 수소 및 산소의 가스량을 조절하면서 rf power를 이용하여 ITO 박막을 증착한 후 전기적, 광학적 특성을 관찰하여 보았다. 또한 ITO 박막의 대면적화 및 양산화를 위하여 Roll to Roll 장비를 적용하였다. 산소 분율 0.3%에서 두께 180 nm 와 면저항 21 ohm/sq.를 나타냈으며 수소 분율 0.8%에서 두께 180 nm, 면저항 22 ohm/sq.이 관찰되었다. 또한 산소 분율 0.3%로 고정한 후 수소 분율을 변화시키며 관찰한 결과 수소분율 0.3%에서 두께 180 nm, 면저항 19 ohm/sq.를 나타내었다.

• Explosives and Blasting
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• v.21 no.1
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• pp.85-94
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• 2003

발파후에 2차연소 또는 폭발(이하, 2차연소라 한다. )이 일어났다는 사실은 폭약이 폭발후에 어떤 가연성가스가 발생하고 그 가연성가스가 잔존하는 폭발열 또는 기타의 점화원에 의해 연소되었음을 의미한다. 폭약이 폭발하였을 때, 발생 가능한 가연성물질은 유리탄소, 일산화탄소, 수소 등으로 추정할 수 있는데 실험결과에서는 가연성물질의 주성분이 수소인 것으로 나타났다. 본 연구에서는 에멀존계 함수폭약이 산소평형, 알루미늄함량, 알루미늄형태와 크기 그리고 포장지의 두께에 따라 수소가 발생되는 양을 가스크로마토그라피를 이용하여 측정하였다. 상기의 열거한 요인들은 모두 수소발생량과 관계가 있는데, 이중에서도 가장 중요한 요인은 산소평형과 알루미늄의 함량인 것으로 나타났다. 한 예로 알루미늄이 15%가 포함되고 산소평형이 -10인 에멀존계 함수폭약은 폭발후에 19.4%의 수소를 함유하고 있는 후가스를 발생시켰으며 이 가스를 포집하여 공기중에 방출시키면서 성냥불을 가까이 하였더니 연소가 되었다. 따라서 에너지를 높이기 위하여 알루미늄의 함량을 높이고 산소평형을 지나치게 마이너스로 설계한다면, 2차연소는 언제든지 발생할 가능성이 있다고 판단된다. 알루미늄의 함량을 가능한 적게, 산소평형을 가능한 0에 가깝게 설계해야 만이 2차연소 현상을 방지할 수 있을 것이며 ㄸ한 최적의 설계뿐만이 아니라 정확한 제조와 품질검사도 2차연소 현상을 방지하는데 중요한 몫을 할 것으로 판단된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.450-452
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• 2022

Recently, various machine learning algorithms have been actively applied to the field of livestock research, including genetic analysis, and have drawn noteworthy results. In this study, the statistical characteristics of meat color, hydrogen ion concentration, water holding capacity (WHC), shear force, and grilling loss that affect the quality of Hanwoo beef are examined using the Hanwoo beef data collected in various environments. Moreover, the prediction of meat quality is also investigated using the two machine learning algorithms, which are linear regression and regression tree. Analysis results show that meat color has the most significant effect on WHC, which determines the tenderness of beef, and hydrogen ion concentration significantly influences shear force and grilling loss. Through this study, we can confirm the applicability of machine learning algorithms in the research on the quality of Hanwoo beef. In addition, this study can also be applied to the prediction and improvement of the quality of Hanwoo beef.

• Polymer(Korea)
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• v.32 no.6
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• pp.566-572
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• 2008

Polyethylene has been prepared via metallocene catalysts [(TMDS)$Cp_2$]$ZrCl_2$, 1, and [$(n-Bu)_2Cp_2$]$ZrCl_2$, 2, in the presence of hydrogen as a chain transfer reagent. Increase of hydrogen flow to the polymerization reactor resulted in the drop of catalytic activity, reduction of molecular weight of polyethylene, getting narrow of molecular weight distribution of polyethylene, and melting point of the polyethylene wax. It should be noticed that it was possible to control molecular weight down to 1500 and melting temperature to 60 $^\circ$C of polyethylene wax using the catalyst 1 that has been developed by authors as well as the catalyst 2 from Exxon.