• Korean Chemical Engineering Research
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• v.45 no.5
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• pp.424-432
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• 2007

Biodiesel is gaining more attractive due to its eco-friendly and the fact that it is prepared from renewable sources. It is monoalkyl esters of long chain fatty acids derived from vegetable oils and animal fats via transesterification reaction with alcohol in the presence of catalyst. This paper will review briefly (1) the effect of reaction conditions such as catalyst type, amount of free fatty acid and moisture, molar ratio of alcohol and oil, alcohol type, reaction temperature and time and stirring intesity, (2) downstream process of biodiesel after transesterification reaction, and (3) potentialities of biodiesel as an alternative fuel based on its properties in diesel engines.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.7
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• pp.474-481
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• 2010

Because international environmental and energy problems such as global warming and ozone depletion, exhausting of fossil energy sources are more serious than before, renewable energy system is attracting people's attention more and more. Organic waste bioenergy system among a variety of renewable energy system is expected to have an effect on building a society which is eco-friendly and recycles resources owing to carbon neutral effects. So this is considered as the role of an energy source of the building. Previous studies on the organic waste bioenergy are mainly bioenergy technology and activation plan of the bioenergy supply. But the performance evaluation studies of bioenergy systems installed in buildings are rarely. This study is to evaluate applicability of the organic waste bioenergy system as the building energy supply system by energy and environmental, economical analysis.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.143-144
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• 2019

Recently, environmental pollution related to global warming is on the rise. Meanwhile, renewable energy is a representative example of many efforts to develop eco-friendly energy to solve the depletion of natural resources and the depletion of petroleum resources in conjunction with global warming. Among them, photovoltaic power generation is increasing the subsidies for the government to increase the production of photovoltaic electricity of the general public, showing a high growth rate. However, polysilicon, which is a raw material of the photovoltaic panel, generates waste called polysilicon sludge in the manufacturing process. In order to produce 1 ton of polysilicon, about 2 tons of waste polysilicon sludge is generated. In 2012, polysilicon sludge was generated at 78,000 tons, with an average of about 220 tons per day. The sludge generated due to insufficient treatment of polysilicon sludge is currently solidified and is processed by landfilling. Therefore, in this study, polysilicone sludge is used as the concept of admixture, and the physical properties of the matrix according to the polysilicon sludge replacement ratio based on light burned magnesia is determined.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.6
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• pp.786-794
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• 2022

Green ammonia is a promising renewable energy carrier. Green ammonia can be used in various energy conversion devices (e.g., engine, fuel cell, etc.). Ammonia has to be fed with hydrogen for start-up and failure protection of some energy conversion devices. Ammonia can be converted into hydrogen by decomposition and partial oxidation. Especially, partial oxidation has the advantages of fast start-up, thermally self-sustaining operation and compact size. In this paper, thermodynamics, start-up and operation characteristics of ammonia partial oxidation were investigated. O₂/NH₃ ratio, ammonia flow rate and catalyst volume were varied as operation parameters. In thermodynamic analysis, ammonia conversion was maximized in the O₂/NH₃ range from 0.10 to 0.15. Ammonia partial oxidation reactor was successfully started using 12 V glow plug. At 0.13 of O₂/HN₃ ratio and 10 LPM of ammonia flow rate, ammonia partial oxidation reactor showed 90% of ammonia conversion over commercial Ru catalyst. In addition, Increasing O₂/NH₃ ratio from 0.10 to 0.13 was more effective for high ammonia conversion than increasing catalyst volume at 0.10 of O₂/NH₃.

• Journal of Environmental Policy
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• v.12 no.1
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• pp.3-35
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• 2013

Through Influence between the qualitative Environment-friendly Planning Elements (Independent variable) of eighty Apartment House on the four boundary areas in Metropolitan 2th Newtown as representative case of domestic Composition case of Eco-City and the quantitative deal price of Apartment House (dependent variable), it was analyzed empirically with use of the statistical measuring technique. This study has been meaning that it was groped the scheme of quantitative measuring analysis on environmental economics through the developmental extention for he classification system of the qualitative Environment-friendly Planning Elements on urban & architecture. And, As the result of empirical analysis, it was confirmed empirically that the economical induction effect was much more weight and worthy of notice through Environment-friendly Planning Elements in Metropolitan 2th Newtown influenced to the deal price of Apartment House, particularly it was found noticeable meaning that Environment-friendly Planning Elements of applicabled the green new techniqe like New & Renewable Energy were used already and it was influenced much to the deal price of Apartment House.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.06a
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• pp.203-204
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• 2014

As the marine environment is becoming more important with growing demand for the marine transport due to the globalization, some advanced ports have made efforts to establish Green Port to protect the marine environment. The Korean ports as the world's fifth ranked country have also made efforts to establish Green Port but most efforts are focused on hardware aspects such as renewable energy generation, installation of AMP and fuel conversion of port facilities. The purpose of this study is to develop Eco-Ship assessment scheme for Green Port in a software aspect and present measures to improve global green-competitiveness of Korean ports through diversification of their efforts for Green Port.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.1
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• pp.26-31
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• 2007

Hydrogen has a high potential to be a renewable substitute for fossil fuels, because of its high gravimetric energy density and environment friendliness. In particular, Magnesium have attracted much interest since their hydrogen capacity exceeds that of known metal hydrides. One of the approaches to improve the kinetic is addition of metal oxide. In this paper, the effect of $Fe_2O_3$ concentration on the kinetics of Mg hydrogen absorption reaction was investigated. $MgH_x-Fe_2O_3$ composites have been synthesized by hydrogen induced mechanical alloying. The powder synthesized was characterized by XRD, SEM and simultaneous TG, DSC analysis. The hydrogenation behaviors were evaluated by using a sievert's type automatic PCT apparatus. Absorption and desorption kinetics of Mg catalyzed with 5,10 mass% $Fe_2O_3$ are determined at 423, 473, 523, 573, 623K.

• Tribology and Lubricants
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• v.38 no.2
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• pp.41-52
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• 2022

Mineral electrical insulating oil, which is widely used in transformers, exhibits excellent cooling performance and transformer efficiency. However, given that it is composed of petroleum-based components, it is weak in terms of biodegradability. This causes environmental problems in case of leakage and a low flash point, which is a factor that would cause great damage in the event of a fire in a substation. In this context, the use of eco-friendly electric insulating oil composed of bio-based vegetable oil and synthetic ester, which has excellent biodegradability and flame retardancy performance, has recently been expanded to the field of electric power, and various research and development (R&D) studies are in progress. According to different research results, vegetable oil and synthetic ester manufacturing technology, thermal stability, oxidation stability, property change, and quality control, which are characteristics of eco-friendly electrical insulating oils, are major factors affecting the maintenance of insulating oil properties. In addition, power companies have established and operated quality control standards according to the use of eco-friendly electrical insulating oil as they expand the exploitatoin of renewable energy in electricity production. In particular, deterioration and oxidation characteristics were jointly identified in R&D as an important influencing factor according to the content of saturated and unsaturated fatty acids present in vegetable oils and synthetic esters in power transformer applications.

• Journal of the Korea Society of Computer and Information
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• v.25 no.3
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• pp.81-88
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• 2020

The Renewable Portfolio Standard(RPS) which is in operated by country for many years is eco-friendly energy business. Although a variety of institute are accessing the RPS, it consists of a centralized system. Also, it shows opacity of data access in user's point of view. And each institutes is possessing their own data collected by themselves. Therefore decentralization and integrated control is demanded. Also, when institutes are attacked, the interruption of RPS can be existed. For resolving this issue, this study proposes the RPS using blockchain. Using the consortium method of blockchain, every institutes has possessing same data inserting REC data in block data, it is resolvable that transparency and security issue as transaction through verification of certain block. Furthermore, in case of one institute is paused by external attack, the role can be replaced by other institutes. This study tried the processing of putting data through ethereum network, therefore it presents the possibility of introducing the blockchain method in RPS.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.73-76
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• 2009

Generally, wind or solar power system is operated as a stand-alone power system, the efficiency of which could be higher by designing wind-solar combined system considering average wind speed and solar radiation of the desert region, Mongolia. This system is designed to generate electricity for power users and pumps the ground water for irrigation using deep well pump. The ground water can be used for farming or forestation where there is no or little irrigation system. In connection with this study, a renewable energy park, Green Eco Energy Park, was developed at about 50km east of Ulaanbaatar. 3 sets of 10kW wind power generator and 70 kW of solar power module were installed there. The electricity generated from the system is used to on-site office building and deep well pump for ground water pumping. A 10kW stand-alone solar pumping system, which has no rechargeable battery system, is installed to pump the ground water with the amount of generated power. The ground water is stored in 3 artificial ponds and then it is used for raising nursery tree and farming. The purpose of this study is to provide a possible energy solution to desert regions where there is no or little power system. The system also supply power to ground water pump, and the water can be used for farming and forestation, which will also be a solution of preventing desertification or spreading of desert area.