• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.5
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• pp.121-126
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• 2020

In many parts of the world, climate warming has caused tremendous environmental disasters to repeat every year. Overuse of fossil fuels, the main source of energy, has affected the global environment, destroying the global ecosystem and depleting resources. To overcome this, efforts to reduce carbon emissions through the development of renewable energy are being actively studied at home and abroad. Already, new technologies are being reported abroad to reduce carbon emissions. Zero Energy House is a model that reduces low carbon emissions and energy use due to the use of high-density materials for high-heated materials, and can live in real life by receiving the minimum required energy through renewable energy. Although the government is trying to apply this in Korea, it is difficult to become common because of the lack of economic feasibility. The purpose of this study is to study models that can zero carbon emissions, which are eco-friendly elements, secure construction economy of zero energy house by using ventilation system, heat exchanger and energy storage system for public use, and attach automation system to window opening/closing to maintain indoor temperature.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.5
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• pp.625-633
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• 2011

Characteristics of a commercial metal hydride (MH) hydrogen supply system have been investigated and an operating strategy was developed based on the experimental data. As a prior step, charging/discharging capacity, thermal properties such as heat capacity, heat of reaction of MH system were experimentally measured. And then P-C-T data for various operating conditions were collected and a correlation between P, C and T predicting the behavior of MH was derived. Based on the basic experimental data, an operating strategy of MH system was developed, in which the hot water temperature supplied into the water jacket of MH was controlled depending on the pressure of MH, thereby the pressure of MH could be maintained at a suitable range. By adjusting the temperature of hot water from $40^{\circ}C$ to $60^{\circ}C$, the maximum discharging capacity of hydrogen could be increased by 4.7%, and consequently more stable hydrogen supply and longer operation time of fuel cell system could be achieved.

• Journal of the Korean Institute of Gas
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• v.28 no.1
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• pp.53-58
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• 2024

Due to the development of industry and improvement of living standards, the amount of natural gas used in the world is constantly increasing, and related industrial facilities such as power plants, storage facilities, and supply pipelines are constantly increasing. Natural gas is a convenient and clean fuel that does not pollute the environment, but in the event of an accident due to leakage, it can cause human casualties, large-scale property damage, and negative effects on the global warming effect. In addition to the severe penalties under the Severe Disaster Punishment Act, it is necessary to ensure safety. Therefore, by applying the principle of laser-based absorption spectroscopy, we developed a long-range portable methane leakage gas detection system that can detect the concentration of methane leaking from a distance of up to 30 meters and verified its effectiveness.

• Explosives and Blasting
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• v.40 no.3
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• pp.19-32
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• 2022

Hydrogen is a fuel having the highest energy compared with other common fuels. This means hydrogen is a clean energy source for the future. However, using hydrogen as a fuel has implication regarding carrier and storage issues, as hydrogen is highly inflammable and unstable gas susceptible to explosion. Explosions resulting from hydrogen-air mixtures have already been encountered and well documented in research experiments. However, there are still large gaps in this research field as the use of numerical tools and field experiments are required to fully understand the safety measures necessary to prevent hydrogen explosions. The purpose of this present study is to develop and simulate 3D numerical modelling of an existing hydrogen gas station in Jeonju by using handheld LiDAR and Ansys AUTODYN, as well as the processing of point cloud scans and use of cloud dataset to develop FEM 3D meshed model for the numerical simulation to predict peak-over pressures. The results show that the Lidar scanning technique combined with the ANSYS AUTODYN can help to determine the safety distance and as well as construct, simulate and predict the peak over-pressures for hydrogen refueling station explosions.

• Korean Chemical Engineering Research
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• v.55 no.3
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• pp.332-340
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• 2017

This study aims to propose a new optimization-based approach for design and analysis of the stand-alone hybrid energy supply system using renewable energy sources (RES). In the energy supply system, we include multiple energy production technologies such as Photovoltaics (PV), Wind turbine, and fossil-fuel-based AC generator along with different types of energy storage and conversion technologies such as battery and inverter. We then select six different regions of Korea to represent various characteristics of different RES potentials and demand profiles. We finally designed and analyzed the optimal RES stand-alone energy supply system in the selected regions using multiobjective optimization (MOOP) technique, which includes two objective functions: the minimum cost and the minimum $CO_2$ emission. In addition, we discussed the feasibility and expecting benefits of the systems by comparing to conventional systems of Korea. As a result, the region of the highest RES potential showed the possibility to remarkably reduce $CO_2$ emissions compared to the conventional system. Besides, the levelized cost of electricity (LCOE) of the RES-based energy system is identified to be slightly higher than conventional energy system: 0.35 and 0.46 $/kWh, respectively. However, the total life-cycle emission of $CO_2$ ($LCE_{CO2}$) can be reduced up to 470 g$CO_2$/kWh from 490 g$CO_2$/kWh of the conventional systems.

• Journal of Soil and Groundwater Environment
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• v.28 no.spc
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• pp.40-54
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• 2023

산업혁명 이후 화석연료의 광범위한 사용, 삼림 벌채, 토지사용의 변화 등과 같은 인위적 활동은 대기 중 온실가스(GHGs, greenhouse gases) 농도를 지속적으로 증가시켜 지구의 기후위기를 유발하였다. 우리나라의 경우 최근 30년 사이 평균 온도가 1.4℃ 상승하였으며, 국제사회의 일원으로 책임을 다하기 위해 2016년 11월 3일 파리협정을 비준하였다. 이에 파리협정의 목표인 산업화 이전 대비 지구 평균온도 상승을 2℃ 아래, 가능한 1.5℃ 아래로 억제하기 위해 2050년까지 CO₂ 순배출량을 0으로 만들어야 하며, 이를 위해 다양한 정책 마련과 함께 경제 및 사회 전반에 걸쳐 많은 노력이 경주되고 있는 실정이다. 탄소중립을 달성하기 위해서는 첫 번째로 GHGs 배출을 줄이고, 두번째로 대기에서 CO₂ 포집을 촉진하기 위해 현재 가동되는 다양한 산업분야의 생산 시스템을 개혁하는 것이 가장 중요한 과제로 고려되고 있다. 그동안 지하수토양 관련 연구분야에서는 지속가능성(sustainability), 복원성(resilience), 녹색성장(green growth) 등과 같은 사회적 요구에 부응하여, 녹색정화(green remediation), 자연 저감(natural attenuation), 탄소포집저장(carbon capture and sequestration), 지열발전등의 기술이 초기단계로 개발이 되고 연구가 되어 왔다. 이러한 기존 연구들은 탄소중립2050의 달성을 위해 고도화되어야하며, 추가적으로 자연 및 인위기원 탄소배출 연구, 토양의 역할을 고려한 저탄소 토지이용 기술, 광물탄산화 등의 연구 및 기술개발이 필요하다고 판단된다. 본 논문에서는 탄소중립2050의 간단한 내용과 함께, 이를 달성하기 위한 지하수토양 분야의 혁신기술 및 선도연구를 소개하였다.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.4
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• pp.500-507
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• 2010

Regard to the global warming, the shipping industries are progressed the dedicated endeavor to reduce greenhouse gas. As the study results of 2009 GHG study team, the $CO_2$ emission of shipping industries exceeded slightly 1.0 billion ton during one year(2007) and it is 3.3% of total $CO_2$ amount exhausted from all industries. This paper are introduced the energy efficiency design index / operation indicator monitoring system(EDiMS) which matched with EVAMOS software released by the dynamics laboratory of Mokpo maritime university. EDiMS can continuously be monitored amounts of $CO_2$, NOx, SOx, and PM emitted from ship and it can be applied as the useful tool of the inventory work of air pollution and the ship energy management plan for the mitigation or reduction of ship emission.

• Journal of the Korean Institute of Gas
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• v.28 no.1
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• pp.73-84
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• 2024

In this study, a quantitative risk impact assessment is performed using an ALOHA program to identify the risks when applying ammonia as fuel for combined cycle power plants as one of the solutions of climate change. The worst and the alternative accident scenarios are established for the Sejong combined cycle power plant and the effective ranges are calculated in terms of flammability, thermal radiation, overpressure and toxicity. The analysis results show that the toxic risk is the most critical and the effective distance is highly proportional to the mixing ratio of natural gas and ammonia by showing the Pearson's correlation coefficient over 98% as 0.991, 0.987 and 0.989 for the Level Of Concern(LOC)-1, LOC-2 and LOC-3, respectively. In addition, the coefficients of linearity for LOC-1, LOC-2 and LOC-3 are calculated to 133, 70 and 29, respectively so it can be confirmed that the effective distance increases as the criterion decreases.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.3
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• pp.174-179
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• 2016

To protect the ocean environment, the use of liquefied natural gas (LNG) carriers, bunkering ships, and fueled ships is increasing. Recently, Korean shipbuilders have developed and supplied a partial reliquefaction facility for boil-off-gas (BOG). Despite reasonable insulation, heat leakage in vessel storage tanks causes LNG to be continuously evaporated as BOG. This research analyzed the maximum liquid yield rate for various partial reliquefaction systems (PRS) and considered related factors affecting yields. The results showed a liquid yield of 48.7% from an indirect PRS system (heat exchanges between cold flash gas and compressed natural gas), and 41% from a direct PRS system (BOG is mixed with flash gas and discharged from a liquid-vapor separator). The primary factor affecting liquid yield was heat exchanger effectiveness; the exchanger's efficiency and insulation characteristics directly affect the performance of BOG reliquefaction systems.

• Membrane Journal
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• v.31 no.5
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• pp.315-326
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• 2021

Lithium ion battery (LIB) demands increase every year globally to reduce the burden on fossil fuels. LIBs are used in electric vehicles, stationary storage systems and various other applications. Lithium is available in seawater, salt lakes, and brines and its extraction using environmentally friendly and inexpensive methods will greatly relieve the pressure in lithium mining. Membrane separation processes, mainly nanofiltration (NF), is an effective way for the separation of lithium metal from solutions. Electrodialysis and electrolysis are other separation processes used for lithium separation. The process of reverse osmosis (RO) is already a well-established method for the desalination of seawater; therefore, modifying RO membranes to target lithium metals is an excellent alternative method in which the only bottleneck is the interfering presence of other metal elements in the solution. Selectively removing lithium by finding or developing suitable NF membranes can be challenging, but it is nonetheless an exciting area of research. This review discusses in detail about lithium recovery via nanofiltration, electrodialysis, electrolysis and other processes.