• Transactions of the Korean hydrogen and new energy society
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• v.26 no.5
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• pp.499-506
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• 2015

Recently the Korean government announced its decision to select the $3^{rd}$ proposal, which targets reducing $CO_2$ by 37% of the BAU level by 2030, for the Intended Nationally Determined Contribution (INDC). According to this proposal, natural gas (or equivalent gas) combined cycle (NGCC) are suggested as alternatives for conventional pulverized coal (PC). In this study, we analyzed the environmental, economic, and energy mixing aspects of synthetic natural gas combined cycle(SNGCC) using NETL material (2011~2012 version) and other domestic materials (2014 version). We found the following conclusions: 1) Considering carbon capture and storage (CCS) integration, $CO_2$ emission factors of SNGCC and supercritical PC are the same. However, 60% of $CO_2$ from SNGCC is produced as high pressure and high purity (99%) gas, making it highly suitable for CCS, which is now strongly supported by the government. 2) Based on the economic analysis for SNGCC using domestic materials and comparison with NGCC, it was found that the settlement price of SNGCC was 30% lower than that of NGCC.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.11a
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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.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.1023-1025
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• 2019

Coal and Natural gas are two biggest contributors to a generation of energy throughout the world. Most of these resources create environmental pollution while making energy affecting the natural habitat. Many approaches have been proposed as alternatives to these sources. One of the leading alternatives is Solar Energy which is usually harnessed using solar farms. In artificial intelligence, the most researched area in recent times is machine learning. With machine learning, many tasks which were previously thought to be only humanly doable are done by machine. Neural networks have two major subtypes i.e. Convolutional neural networks (CNN) which are used primarily for classification and Recurrent neural networks which are utilized for time-series predictions. In this paper, we predict energy generated by solar fields and optimal angles for solar panels in these farms for the upcoming seven days using environmental and historical data. We experiment with multiple configurations of RNN using Vanilla and LSTM (Long Short-Term Memory) RNN. We are able to achieve RSME of 0.20739 using LSTMs.

• Journal of Soil and Groundwater Environment
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• v.25 no.3
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• pp.12-22
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• 2020

Managed aquifer recharge (MAR) is a promising water management strategy for securing stable water resources to overcome water shortage and water quality deterioration caused by global environmental changes. A MAR demonstration site was selected at Imgok-ri, Sangju-si, Korea, based on screening for the frequency of drought events and local water supply situations. The abundant groundwater discharging from a nearby abandoned coal mine is one of the potential recharge water sources for the MAR implementation. However, it has elevated levels of arsenic (~12 ㎍/L). In this study, the potential of the natural attenuation of arsenic by the field geological media was investigated using batch and column experiments. The adsorption and desorption parameters were obtained for two drill core samples (GM1; 21.8~22.8 m and GM2; 26.0~27.8 m depth) recovered from the potentially water-conducting fracture-zones in the injection well. The effluent arsenic concentrations were monitored during the continuous flow of the mine drainage water through the columns packed with the core samples. GM2 removed about 60% of arsenic in the influent (0.1 mg-As/L) while GM1 removed about 20%. The results suggest that natural attenuation is an acitive process occurring during the MAR operation, potentially lowering the arsenic level in the mine drainage water below the regulatory standard for drinking water. This study hence demonstrates that using the mine drainage water as the recharge water source is a viable option at the MAR demonstration site.

• Korean Chemical Engineering Research
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• v.52 no.2
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• pp.154-165
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• 2014

Development of unconventional natural resources such as shale gas, shale oil and coal bed methane, has been activated and improved the productivity due to the recent technology advance in horizontal drilling and hydraulic fracturing. However, the flowback water mixed with chemical additives, and the brine water containing oil, gas, high levels of salts and radioactive metals is produced during the gas production. Potential negative environmental impact due to large volumes of the produced wastewater is increasingly seen as the major obstacles to the unconventional natural resource development. In this study an integrated framework for the flowback and brine water treatment is proposed, and we reviewed the upcoming state of the art technology in water treatment. Basic separation processes which include not only membrane, evaporation, crystallization and desalination processes, but the potential water reuse and recycling techniques can be applied for the unconventional natural resource industry.

• Journal of the Korea Concrete Institute
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• v.27 no.5
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• pp.531-539
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• 2015

Properties of normal-strength mortar containing coarsely-crushed coal bottom ash considering standard particle size distribution of fine aggregate were investigated. Mortar containing raw bottom ash was applied as a reference. By crushing the bottom ash with a particle size larger than fine binder but smaller than fine aggregates, i.e., coarse-crushing, water absorption and specific gravity of the particles could be controlled as similar levels to those of natural fine aggregates. Workability and strength of the mortar were not changed and even increased when the coarsely-crushed bottom ash was added considering standard particle size distribution in Standard Specification for Concrete, while those were decreased when raw bottom ash was added without any treatment. When a replacement ratio of coarsely-crushed bottom ash was less than 30 vol.%, there were no significant decrease in dynamic modulus of elasticity and dry shrinkage of the mortar.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.5
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• pp.685-695
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• 2004

Size-segregated measurements of aerosol composition are used to estimate the transport of natural and anthropogenic aerosols at Gosan site during May 2002. The results of measurement show that not only soil dust but also anthropogenic aerosols, including sulfur and enriched trace metals such as Pb, Zn, Cu, are transported to Gosan. This study combines the size- and time-resolved aerosol composition measurements with factor analysis in order to identify some source materials. As a result, coarse particles (2.5${\mu}m$~12${\mu}m$) are influenced by soil, sea-salt, coal, coal combustion, and nonferrous sources. But fine particles have different sources. The fine particles, which the diameter is from 0.56${\mu}m$ to 2.5${\mu}m$, are more affected by road dust, oil combustion, industry. municipal incineration, and ferrous metal sources. The very fine particles, from 0.09${\mu}m$ to 0.56${\mu}m$, mainly supplied by biomass burning, oil combustion, nonferrous and ferrous metal sources.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.345-348
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• 2008

본 연구에서는 가스화 반응, 수성가스 전환 반응, 메탄화 반응 등으로 구성된 SNG제조 공정에 대한 해석을 통해, 석탄 촤의 가스화 반응에 의해 생성된 합성가스를 이용한SNG제조 공정 특성을 파악하고자 하였고, SNG제조 공정 중 가스화 공정에 대한 실험을 통해 가스화 공정의 조건에 따른 합성가스 발생 특성 및 메탄화 반응의 특성을 살펴보았다. 석탄 촤를 대상으로 하여 가스화 공정의 $O_2$/feed ratio와 steam/feed ratio 조건 변화에 따른 합성가스 발생 특성을 살펴본 결과 steam을 투입하지 않은 경우 발생되는 합성가스 중 CO의 농도는 55$\sim$65%, $H_2$ 9$\sim$11%, $CO_2$ 24$\sim$29% 범위였고, $O_2$/feed ratio가 증가할수록 CO의 농도는 증가하고, $H_2$와 $CO_2$의 농도는 감소하는 경향을 나타내었다. 또한,steam을 투입하는 경우 합성가스 중 CO의 농도는 20$\sim$37%, $H_2$ 16$\sim$18%, $CO_2$ 42$\sim$55% 범위였다. 메탄화 공정 해석 결과 메탄의 농도를 최대로 얻을 수 있는 조건은 $H_2$/CO 비가 3인 조건이었고 온도가 낮을 수록 생성농도가 높아짐을 알 수 있었다. 가스화 특성 실험 결과 및 공정해석 결과, 메탄화 반응에 대한 실험 및 공정해석 결과는 고체시료의 가스화 반응을 통해 발생한 합성가스를 이용한 SNG 제조 공정 특성 파악 및 SNG를 제조하기 위해 필요한 단위 공정에 대한 설계 자료 및 운전조건을 결정할 수 있는 주요 인자로 활용될 수 있을 것으로 판단된다.

• Journal of Energy Engineering
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• v.5 no.1
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• pp.8-18
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• 1996

As a part of comprehensive IGCC process simulation, the thermal performance analysis was performed for coal gas firing combined power plant. The combined cycle analyzed consisted of il Texaco gasifier and a low temperature gas cleanup system for the gasification block and a GE 7FA gas turbine, a HRSG and steam turbine for the power block. A steady state simulator called ASPEN(Advanced System for Process Engineering) code was used to simulate IGCC processes. Composed IGCC configuration included air integration between ASU and gas turbine and steam integration between gasifier, gas clean up and steam turbine. The results showed 20% increase in terms of gas turbine power output(MWe) comparing with natural gas case based on same heat input. The results were compared with other study results which Bechtel Canada Inc. performed for Nova Scotia power plant in 1991 and the consistency was identified within two studies. As a result, the analysing method used in this study is verified as a sound tool for commercial IGCC process evaluation.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.12
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• pp.587-613
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• 1999

Environmental problems such as global climate change, depletion, ocean and air pollution, and resource degradation-compounded by an expanding world population-respect no border and threaten the health, prosperity and jobs of all mankind. Our efforts to promote democracy, free trade, and stability in the world will fall short unless people have a livable environment. We have an enormous stake in the management of the world's resources. By increasing demand for timber, natural gas, coal and consumer's goods have destroyed the grounds for living. Greenhouse gas emissions anywhere in the world have threatened coastal communities, and then changed the Earth's climate system. The burning of coal, oil, and other fossil fuels is increasing substantially the concentration of heat-trapping gasses such as carbon dioxide, methane, and nitrous oxide in our air. The earth's temperature and sea levels are rising as a result. Since 1972 there has been a marked growth in the number and scope of environmental treaties. In particular, after the 1992 Rio Conference, international legal instruments became more concentrated on addressing environment within the context of sustainable development and incorporated a number of new concepts and innovative approaches. A preliminary analysis of recent conventions and in particular those associated with the Rio Conference indicates various ideas, concepts and principles which have come to the fore including sustainable development, equity, common concern of humankind, common but differentiated responsibilities and global partnership. However, international trade also has an environmental impact which must be minimized or countered. Positive measures are to be preferred to achieve environmental goals, but where trade provisions are necessary, they should be appropriately used within environmental conventions to facilitate the reduction and limitation of the negative impacts of trade and to enhance the complementarity of the multilateral trade regime with the imperatives of environmental protection, in the interests of environmental protection and sustainable development generally. The international community has to recognize and endorse this need to achieve complementarity between trade and environment issues.