• Korean Chemical Engineering Research
• /
• v.57 no.3
• /
• pp.400-407
• /
• 2019

Oxy-combustion with a circulating fluidized bed (Oxy-CFBC) technology has been paid attention to cope with the climate change and fuel supply problem. In addition, Oxy-CFBC technology as one of the methods for carbon dioxide capture is an eco-friendly that can reduce air pollutants, such as $SO_2$, NO and CO through a flue gas recirculation process. The newly developed $100kW_{th}$ pilot-scale Oxy-CFBC system used for this research has been continuously utilizing to investigate oxy-combustion characteristics for various fuels, coals and biomasses to verify the possibility of fuel diversification. The anthracite is known as a low reactivity fuel due to a lot of fixed carbon and ash. Therefore, this study aims not only to improve combustion efficiency of an anthracite, but also to capture carbon dioxide. As a result, compared to air-combustion of sub-bituminous coal, oxy-combustion of anthracite could improve 2% combustion efficiency and emissions of $SO_2$, CO and NO were reduced 15%, 60% and 99%, respectively. In addition, stable operating of Oxy-CFBC could capture above 94 vol.% $CO_2$.

• Journal of Hydrogen and New Energy
• /
• v.31 no.4
• /
• pp.351-362
• /
• 2020

Recently, renewable power is rapidly increasing globally due to extensive effort to mitigate climate change and conventional power generation industry faces new challenges. The gas turbine technology has potentials to expand its role in future power generation based on the intrinsic characteristics such as fuel diversity and fast load following ability. Hydrogen is one of the most promising fuel in terms of reducing emissions and storing variable renewable energy and replacing hydrocarbon fuel with hydrogen has become very popular. Therefore, this paper presents the core technologies to combust hydrogen added fuel efficiently in gas turbines and the analysis of domestic and international R&D trends.

• Journal of the Korean Institute of Gas
• /
• v.15 no.1
• /
• pp.9-14
• /
• 2011

Heavy duty diesel engine has relatively small portion of whole vehicles due to long drive distance and large engine displacement, but largely influences atmosphere environment. City buses changed to CNG (Compressed Natural Gas) bus with Korea-Japan Worldcup. Heavy duty truck and intercity bus, however, were impossible to use CNG because those kinds of vehicles had long drive distance and CNG station was installed mainly at the around of the bus garage of city. Insulation container storing the natural gas as a liquid makes heavy duty truck and intercity bus possible to use the natural gas. Drive using diesel is possible where is hard to recharge the gas. With LNG (Liquefied Natural Gas), the dependence on oil is largely decreased, PM (Particulate Matter) and NOx which is chronic disadvantage of diesel is remarkably reduced and finally $CO_2$, the representative green house gas, is reduced over 10%.

• Monthly Duck's Village
• /
• s.92
• /
• pp.50-59
• /
• 2011

2008년 급등하였던 국제곡물 가격은 209년 들어 하락하여 2010년 상반기까지 안정세를 보였으나, 기상악화로 인한 구소련 지역의 밀 생산 감소로 러시아가 수출 금지 조치를 취하면서 2010년 7월부터 밀 가격 급등을 시작으로 현재까지 강세를 보이고 있다. 옥수수 국제 가격 상승은 사료비 상승의 주된 요인으로 작용하여 축산 농가의 수익성을 악화시키고, 밀과 대두 국제 가격 상승은 이를 원료로 하는 가공품 가격 상승으로 이어져 소비자들의 부담으로 연계된다. 따라서 본고에서는 2008년의 애그플레이션 경험을 토대로 최근의 국제곡물 가격상승 원인과 2011년 상반기 국내 물가에 미치는 영향을 분석하고, 시사점을 제시하였다. 최근의 국제곡물 가격 상승은 생산 감소, 수요 증가, 곡물 선물 투기 증가에서 기인하고 있다. 2010/11년도 세계 곡물 생산량은 전 세계적인 이상기후로 전년보다 2% 감소하고, 소비량은 2.4% 증가하여 곡물 기말재고율은 전년대비 3.1%p 하락할 것으로 예상된다. 향후 바이오연료 소비는 지속적으로 증가할 전망이며, 이에 따른 세계 곡물 수요 증가는 불가피해 보인다. 곡물 수급이 전년보다 좋지 않은 상황에서 곡물 선물에 대한 투기가 증가하고, 중국과 인도의 육류 소비 증가에 따른 곡물 소비 증가도 국제곡물 가격 상승의 주된 원인으로 작용하고 잇다. 2010년 하반기 국제곡물 가격을 적용하면, 2011년 상반기 국내 물가 상승은 불가피한 것으로 나타났다. 2011년 상반기 국제곡물 가격을 적용하면, 2011년 상반기 국내 물가 상승은 불가피한 것으로 나타났다. 2011년 상반기 배합사료는 2010년 6월 시세보다 11.5%, 제분 부문은 31.3%, 유지 및 식용유는 6.6%, 제당 부문은 30.0%의 물가 상승요인이 있는 것으로 나타났다. 한편 전분 및 당류는 전년 6월대비 10.9%의 물가 상승요인이 있을 것으로 예상된다. 이와 같이 밀, 옥수수, 대두의 대부분을 수입에 의존하는 우리나라는 국제곡물 가격이 상승할 경우 국내물가 상승이 불가피한 실정이며, 국내 생산을 늘린다 하더라도 수요량을 충족하기에는 한계가 있다. 따라서 국제곡물 수급 및 가격을 상시 모니터링하여 향후 국제곡물 가격을 전망하는 관측시스템 개발을 통해 조기경보를 주고, 이에 따른 매뉴얼을 만들어 대응해야 할 것이다. 한편, 정부 차원에서는 세계 곡물 생산량 감소와 수요 증가로 곡물 공급에 차질이 생길 경우 수입선 다변화 등의 빠른 정책적 대응을 위해 주요 곡물 생산국과의 네트워킹을 강화시킬 필요가 있다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.519-521
• /
• 2022

As appearance of diverse electric power supplies and fuel cells have been emerging, UAVs have capacity to prolong their flight missions. Nowadays, the rotary based UAVs that are commonly distributed on the open market, adapt rechargeable batteries and have around 50 centimeters in width and generally within 30 minutes in hovering flight capacities. UAV's flight time highly depends on the capacity and the weight of its batteries. To cope with the flight time, recharging methods are also being researched. their researches are mainly divided into coupled and decoupled in manner. In this article, we propose the method to refine the position more effectivly and precisely adapting QR Code and 3-D position estimation so that UAVs enable to land on the recharging system successfully.

• Environmental and Resource Economics Review
• /
• v.31 no.1
• /
• pp.113-139
• /
• 2022

The iron and steel industry is a manufacturing industry with the largest greenhouse gases emissions and has a great ripple effect on the national economy as a core material industry. This study internationally compared the decoupling patterns of greenhouse gases emissions in the iron and steel industry from 1990 to 2019, focusing on Korea, Japan, and Germany. In particular, unlike previous studies that considered only fuel combustion emissions, this study considered all fuel combustion emissions, industrial process emissions, and indirect emissions from the use of electricity and heat. As a result of the analysis, Korea is interpreted as expansive coupling, Japan as decoupling, and Germany as unclear. Therefore, the decoupling path that the Korean iron and steel industry should take should not be in Germany, but in the form of seeking a decoupling method similar to Japan or more effective than Japan. In addition, this study considered the characteristics of the iron and steel industry as much as possible and presented the causes of the decoupling analysis results and implications for the Korean iron and steel industry through comparison with Japan and Germany. In particular, four factors were suggested as factors which has promoted decoupling in Japan: high value-added of Japanese iron and steel products, development of energy efficiency technology in the Japanese iron and steel industry, strategic M&A of the Japanese iron and steel industry, and maintaining competitiveness according to the closed distribution structure of Japanese iron and steel products. The Korean iron and steel industry should also use the case of Japan as a benchmark to further increase added value through quality uprade and product diversification of iron and steel products, while at the same time making efforts to fundamentally reduce greenhouse gas emissions through the development of new technologies.

• Journal of the Korean Applied Science and Technology
• /
• v.32 no.2
• /
• pp.348-361
• /
• 2015

To reduce the effects of greenhouse gas (GHG) emissions, the government has announced the special platform of technologies as parts of an effort to minimize global climate change, and the government distributed biodiesel since 2006 as the further efforts. Although there are some debates about some quality specifications and unbalanced of source (44% from palm oil), more than 400kton/year of biodiesel was produced in 2013. Moreover the amounts will be increased when the RFS is activated. To solve the unbalanced situation and to achieve the diversity of feeds, it is essential that many researches should be considered. Especially, free and bond glycerines are one of the important properties seriously affected to the combustion system in vehicle & cold properties. Previous method (KS M 2412) couldn't cover the biodiesel derived from lauric oil($C_{12:0}$) such as PKO (Palm Kernel Oil), Coconut oil because those compositions are lighter than other conventional biodiesel sources. In this study, we review the existed method and figure out the factors should improve to analysis the glycerine from PKO and Coconut oil biodiesel. Modifying the analysis conditions to enhance the resolution and change the internal standards to avoid the overlapped- peaks between Capric acid ME ($C_{10:0}$) and standard#1(1,2,4-butantriol). From this revised method, we could solve the restrictions of previous methods. And check the possibility of new method to analyze the glycerine in biodiesel regardless of sources.

• Journal of the korean Society of Automotive Engineers
• /
• v.18 no.5
• /
• pp.53-68
• /
• 1996

마그네슘이 자동차 경량화에 관심이 되는 이유는 근본적으로 CAFE 규제와 같이 경량화를 통한 화석연료의 소모를 크게 억제해야 한다는 사회적인 규제이나, 지난 10여년간의 기술발전으로 내식성이 나쁘다거나 취급이 위험한 금속이라는 인식이 크게 개선된 데에도 있다. 다른 경량금속에 대한 Mg 지금 가격의 비교조건이 호전되었고 향후 원소 재공급의 다변화가 추진되고 있는 것도 환경을 변화시킨 중요한 요인이다. 그간 중요한 경량화 대체 재료로 연구투자가 많았던 유기고분자 재료 및 FRP 등과 같은 복합재료는 폐기부품의 재활용이 어려움 때문에 호나경친화적인 단점이 부각되어, 이 소재의 증가가 주춤해 있다. 마그네슘의 경우에는 재활용이 가능하고, 진동흡수효과가 매우 커서 소음발생을 크게 줄일 뿐만 아니라, 주행 및 내구성시험에서 치수안정성이 좋고 많은 종류의 전자기기 사용에 의한 전자파 차폐효과도 큰 장점을 가지고 있다. 본 고에서는 Mg 다이캐스팅으로 자동차부품의 경량화 현황과 선진국에서 보는 전망을 미국을 중심으로 정리하고, 이와 관련한 Mg 다이캐스팅으로 자동차부품의 경량화 현황과 선진국에서 보는 전망을 미국을 중심으로 정리하고, 이와 관련한 Mg 기술적인 이슈와 시장전망도 서술하였다. 그리고 현재 우리나라의 연구계와 부품업계에서 추진하고 있는 연구개발 동향을 자동차 업계에 소개하는 의미도 있다. 이처럼 우리나라의 현황을 정리해 보는 것은 국내 자동차 산업이 국제적인 경쟁을 하고 있고 Mg기술과 원료확보에서 일본의 견제를 받고 있는 우리의 현실에서도 필요한 작업으로 생각된다.값들로 구성되는 형상을 내구 성능, 성형성등을 고려하여 최종 형상으로 결정한다. 내구성능의 예측은 금속부품의 내구수명 예측에 널리 이용되고 있는 방법이 방진 고무부품의 경우에도 적용 가능한지를 검토하고, 방진 고무부품에도 일반적으로 적용될수 있는 내구수명 예측방안의 개발 가능성을 타진해 보았다. 본 연구의 목표는 시제품을 제작하기 이전에 설계된 부품에 대한 스프링 상수 및 내구특성을 체계적으로 규명하여 제품 시험의 횟수를 줄이고, 보다 정밀한 제품을 제작할 수 있도록 하기 위한 것이다.세포수는 초기 배반포기배에서 팽윤 배반포기배로 진행됨에 따라 두배에서 세배 정도 증가되었음을 알 수 있었다. 또한, differential labelling과 bisbenzimide기법에서 얻어진 각각의 총세포수를 비교하였을 때 총세포수는 발달의 진행 정도에 따라 증가되며 그와 동시에 동일한 군 간의 세포수도 거의 유사함을 알 수 있었다. 따라서, ICM과 TE를 differential labelling하는 기법은 수정란의 quality를 평가하는데 매우 유용한 기법으로서 착상전 embryo 발달을 연구하는데 효과적으로 이용될 수 있다는 것을 시사한다. 고도의 유의차를 나타낸 반면 비수구, 초생수로구 및 Bromegrass 목초구 간에는 아무런 유의차가 인정되지 않았다. 7. 농지보전 처리구인 배수구와 초생수로구는 비처리구에 비해 낮은 침두 유출량과 낮은 토양유실량을 나타내었다.구보다 14% 절감되는 것으로 나타났다.작용하는 것으로 사료된다.된다.정량 분석한 결과이다. 시편의 조성은 33.6 at%

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.14 no.4
• /
• pp.141-147
• /
• 2010

Liquefied natural gas(LNG) is natural gas that has been converted temporarily to liquid form for ease of storage and transport it. Natural gas is the worlds cleanest burning fossil fuel and it has emerged as the environmentally preferred fuel of choice. In Korea, the demand of this has been increased since the first import from the Indonesia in 1986. LNG takes up about 1/600th the volume of natural gas in the gaseous state by cooling it to approximately $-162^{\circ}C(-260^{\circ}F)$. The reduction in volume therefore makes it much more cost efficient to transport and store it. Modern LNG storage tanks are typically the full containment type, which is a double-wall construction with reinforced concrete outer wall and a high-nickel steel inner tank, with extremely efficient insulation between the walls. The insulation will be installed to LNG outer tank for the isolation of cryogenic temperature. The insulation will be installed in the base slab, wall and at the roof. According to the insulation's arrangement, the different aspects of temperature transmission is shown around the outer tank. As the result of the thermal & stress analysis, by the installing cellular glass underneath the perlite concrete, the temperature difference is greatly reduced between the ambient temperature and inside of concrete wall, also reducing section force according to temperature load.

• Journal of Venture Innovation
• /
• v.5 no.1
• /
• pp.91-106
• /
• 2022

Cryptocurrency, stood out the sharp cost rising of Bitcoin has been spotlighted by means of the solution for stagflation because it is decentralized with an existing currency differently. Especially getting into 4th industrial revolution, technologies using block chain and internet of things have been used in the many fields, and the power of influence is also widespread. Nevertheless like a remark of Elon Musk of Tesla CEO, the problems of environmental contamination for cryptocurrency have been pointed out continuously and the most representative of them is an enormous electric usage as the use of fossil fuels. Also the amount generated of carbon dioxide result in the acceleration of global warming mainly based on the climate changes of earth if the existing mining method is continued. On the other hand, review researches have been conducted restrictively as the connection with environmental contamination as the mining of cryptocurrency. In this study, it intended to review problems for environmental contamination as the diversification of ecological system of cryptocurrency concretely. Upon investigation existing prior documents on the putting recent data first, the mining of cryptocurrency has affected on the environmental contamination conflicting with carbon neutrality as increasement of the electric usage and electronic wastes. And POS method without the mining process appeared, but it had a demerit collapsing a decentralization and then we met turning point on appearing various environmental-friendly cryptocurrency. Finally the appearance of cryptocurrency using new renewable energy acted on the opportunity of the usage maximization of energy storage apparatus and the birth of national government intervention. Based on these results, we mention clearly that hereafter cryptocurrency will regress if not go abreast the value of currency as well as environmental approach.