• 한국수소및신에너지학회논문집
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• 제27권6호
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• pp.737-746
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• 2016

This article describes a comparison on laminar burning velocity measured by Bunsen and spherical flame methods of synthetic natural gas (SNG) with various composition of hydrogen. In this study, the laminar burning velocity measurements were employed by Bunsen burner and cylindrical constant combustor at which flame images were captured by Schlieren system. These results were also compared with numerical based on CHEMKIN package with GRI 3.0, USC-II and UC Sandiego mechanism. In case of spherical flames, the suitable flame radius range and theoretical models were verified using the well-known previous results in methane/air flames. As an experimental condition, hydrogen content of SNG was adjusted 0% to 11%. Equivalence ratios of Bunsen flames were adjusted from 0.8 to 1.6. On the other hand, those of spherical flames were adjusted from 0.6 to 1.4, relatively. From results of this study, the both laminar burning velocities measured in Bunsen and spherical flame methods were resulted in similar tendency. As the hydrogen content increased, the laminar burning velocity also increased collectively. Laminar burning velocity of measured SNG-air flames was best coincided with GRI 3.0 mechanism by comparison of reaction mechanisms.

• 대한화학회지
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• 제5권1호
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• pp.66-72
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• 1961

A small size Fischer-Tropsch Catalyst testing apparatus, designed for an operating pressure of 150 psig, was test fabricated from ordinary schedule 40 iron pipes. The operability of the apparatus was tested by charging the reactor tube with the Lurgi Fischer-Tropsch iron Catalyst and passing through it the water gas obtained by gasifying the Korean anthracite using steam and oxygen. With the kind of catalyst charged, the apparatus was proven to daily produce about 50c.c. of synthetic greasy product, water and water soluble compounds, by running at a temperature of $250^{\circ}C$ and at a space velocity of 180 volume of gas per volume of catalyst/hr. About 20 consecutive days of operation is claimed to be sufficient for gathering an enough amount of synthetic products for such ordinary tests as distillation analysis, density measurement, iodine value determination etc. This trial fabrication of apparatus may be the first case of its kind in Korea in that the work has been conducted out in much a pilot plant scheme rather than a routine laboratory way which depends on small glass ware apparatus.

• 한국기계가공학회지
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• 제20권11호
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• pp.80-85
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• 2021

The gasification of coffee leaves, which are a type of biomass waste, was conducted on a pilot of a downdraft fixed gasification system to investigate the gasification characteristics. The experiment was performed using a coffee leaf pellet size and a batch-type gasification system consisting of a gasifier, cooling cyclone, scrubber, and bag filter. It was found that the air-to-fuel ratio was 2.32 Nm³/kg·h and the reaction temperature was 700 ℃-900 ℃. However, the air flow rate changed to 0.45 Nm³/min, which was lower than the initial starting value depending on the temperature change during the gasification process. It was concluded that coffee leaves can be converted from biomass waste into useful synthetic gas as an alternative energy source.

• Tribology and Lubricants
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• 제36권3호
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• pp.139-146
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• 2020

Global warming has led to an increase in demand of eco-friendly vehicles, such as electric cars, for reducing greenhouse gas emissions, and especially, regulating carbon dioxide generation. In addition, electric vehicles are equipped with an electric drive-type hermetic scroll compressor and a refrigerant, which exhibit current and future trends of using environmentally friendly refrigerants, including R-1234yf. In this study, polyol ester-based refrigeration oils are prepared via condensation esterification of polyol and fatty acids. The oils can be combined with R-1234yf refrigerant for applications in air conditioning and cooling systems of electric vehicles. The structure of synthetic polyol esters is confirmed via ¹H-NMR and FT-IR spectrum analysis, and the composition of the polyol ester is analyzed via gas chromatogram analysis. Furthermore, kinematic viscosity, viscosity index, total acid value, pour point, and color are analyzed as fundamental physical properties of the synthetic polyol esters. The compatibility and chemical stability of the synthetic polyol ester combined with the R-1234yf refrigerant are obtained via high temperature and high pressure oil-resistant refrigerant tests. The changes in the oil color and catalyst activity are observed before and after the experiment to determine whether it is suitable as a refrigerator oil.

• 자원환경지질
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• 제53권6호
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• pp.793-807
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• 2020

그린뉴딜정책의 실현은 석탄을 연료에서 원료로 활용분야로의 전환을 촉진시킬 것이다. 석탄은 수소의 생산, 인조 흑연 및 활성탄의 제조 원료로 활용될 수 있다. 석탄은 Steam carbon(SC) 반응과 Water-Gas Shift(WGS) 반응 및 탄산화 반응을 통하여 수소를 생산할 수 있으며, CO2격리기술과 연동되어 사용되어야 한다. 인조흑연은 실리콘이나 철 등의 무기촉매의 존재하에서 탄화도가 높은 무연탄 등을 2400~2800℃의 흑연화 온도까지 열처리함으로서 제조될 수 있기 때문에 무연탄은 석유계 피치에 비해 원료 가격경쟁력 측면에서 잠재성이 있다. 한편, 최근 목질기원의 활성탄에 필적하는 넓은 비표면적 혹은 많은 양의 미세기공을 가진 석탄기원의 활성탄이 제조될 수 있음을 여러 연구를 통해 확인되었다. 따라서 석탄기원의 활성탄은 목질기원의 활성탄을 대체할 수 있을 것으로 기대된다.

• 한국연소학회지
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• 제18권2호
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• pp.17-22
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• 2013

In this study, we tested the absorption of $CO_2$ in combustion gas into an alkaline wastewater to simultaneously control $CO_2$ and wastewater. During the experiment, we investigated the effects of operating parameters on neutralization characteristics of the wastewater by using $CO_2$ in a bench-scale semi-batch jet loop reactor (0.1 m diameter and 1.0 m in height). The operating parameters investigated in the study are gas flow rate of 1.0-2.0 L/min, liquid recirculation flow rate of 4-32 L/min, and liquid temperature of $20-25^{\circ}C$. It was shown that the initial pH of wastewater rapidly decreased with increased gas flow rate for a given liquid recirculation flow rate. This was due to the increase in the gas holdup and the interfacial area at higher gas flow rate in the reactor. At constant gas flow rate, the time required to neutralize the wastewater initial pH of 10.1 decreased with liquid recirculation flow rate ($Q_L$), reached a minimum value in the range of $Q_L$ = 16-24 L/min, and then increased with further increase in $Q_L$. Further, the time required to neutralize the wastewater was shortened at higher temperatures.

• 한국연소학회지
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• 제18권3호
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• pp.38-43
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• 2013

In this study, we tested the absorption of $CO_2$ in combustion gas into an alkaline wastewater to simultaneously control $CO_2$ and wastewater. During the experiment, we investigated the effects of operating parameters on neutralization characteristics of the wastewater by using $CO_2$ in a bench-scale semi-batch jet loop reactor (0.1 m diameter and 1.0 m in height). The operating parameters investigated in the study are gas flow rate of 1.0-2.0 L/min, liquid recirculation flow rate of 4-32 L/min, and liquid temperature of $20-25^{\circ}C$. It was shown that the initial pH of wastewater rapidly decreased with increased gas flow rate for a given liquid recirculation flow rate. This was due to the increase in the gas holdup and the interfacial area at higher gas flow rate in the reactor. At constant gas flow rate, the time required to neutralize the wastewater initial pH of 10.1 decreased with liquid recirculation flow rate ($Q_L$), reached a minimum value in the range of $Q_L$ = 16-24 L/min, and then increased with further increase in $Q_L$. Further, the time required to neutralize the wastewater was shortened at higher temperatures.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1999년도 추계 학술발표회 논문집
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• pp.23-29
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• 1999

Experimental studies are conducted to investigate the flame stability and the thermal/fuel NOx formation characteristics of the low calorific value (LCV) coal derived gas fuel. Synthetic LCV fuel gas is produced by mixing carbon monoxide, hydrogen, nitrogen and ammonia on the basis that the thermal input of the syngas fuel into a burner is identical to that of natural gas. The syngas mixture is fed to and burnt with air on flat flame burner. With the variation of the equivalence ratio for specific syngas fuel, flame behaviors are observed to identify the flame instability due to blow-off or flashback and to define stable combustion range. Measurements of NOx content in combustion gas are made for comparing thermal and fuel NOx from the LCV syngas combustion with those of the natural gas one. In addition, the nitrogen dilution of the LCV syngas is preliminarily attempted as a NOx reduction technique, and its effects on thermal and fuel NOx production are discussed.

• 한국가스학회지
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• 제21권1호
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• pp.1-5
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• 2017

독성가스 사고 시 토양 침적은 사고피해범위에 영향을 미치는 주요 변수이다. 본 연구에서는 토양의 깊이 및 유기물 함량 비율이 독성가스 염소의 토양 침적 특성에 미치는 영향을 연구하였다. 실험에 이용된 장치로는 미국의 Air Force Research Laboratory에서 구축한 장치를 벤치마킹하였다. 다양한 합성토양을 이용해 유기물의 함량을 변화시키면서 토양 침적실험을 진행하였다. 다양한 합성토양에 일정 농도의 염소를 노출시킨 후, 염소 침적의 정도를 정량화하기 위해 음이온 크로마토그래피를 이용하여 침적량을 측정하였다. 그 결과, 토양 표면에서의 침적량 변화에 비해 깊이에 따른 침적량의 변화 경향은 볼 수 없었으나, 염소 노출 시간에 따른 표면 침적량의 차이는 증가함을 확인 할 수 있었다. 또한, 유기물 함량에 따른 침적량은 유기물 함량이 증가함에 따라 비례관계를 보였다. 토양 표면에서의 염소 침적량의 증가는 주로 토양 내 유기물 함량에 의존함을 확인하였다.

• 센서학회지
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• 제23권4호
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• pp.266-271
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• 2014

Chemical sensors are used in various industrial facilities such high-risk and prevent the leakage of substances, important in life and environmental protection and the safe use of industry, used for management. In particular, high-temperature environments such as power generation equipment of the rotating part due to leakage generated by the various oil, power plants Shut Down, fire, work environment (exposure to various chemical solution and gas leak) and various water, air and soil pollution causes. Thus, over the long term through various channels such as crops and groundwater contamination caused by the slow, serious adverse effect on the ecosystem. In this paper, synthetic lube oil and high pressure hydraulic fluid leakage and immediately detect a new Printed Electronic implementation of technology-based film-type sensors, and its performance test. Thus, industrial accidents and environmental pollution and for early detection of problems, large accidents can be prevented. Experimental results of the synthetic lube oil and high pressure hydraulic fluid solution after the contact time depending on the experiment and the oil solution of the sensor material of the conductive porous PE resistance value by a chemical reaction could be confirmed that rapid increase. Also implemented in the film-type oil sensor electrical resistance change over time of the reaction rate and the synthetic lube oil is about 2 minutes or less, the high pressure hydraulic fluid is less than about 1 minute was. Therefore, more high-pressure hydraulic fluid such as a low volatility synthetic lube oils are the resistance change and the reaction rate was confirmed to be the slowest.