• Korean Journal of Materials Research
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• v.18 no.12
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• pp.650-654
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• 2008

The emission of carbon dioxide from the burning of fossil fuels has been identified as a major contributor to green house emissions and subsequent global warming and climate changes. For these reasons, it is necessary to separate and recover $CO_2$ gas. A new process based on gas hydrate crystallization is proposed for the $CO_2$ separation/recovery of the gas mixture. In this study, gas hydrate from $CO_2/H_2$ gas mixtures was formed in a semi-batch stirred vessel at a constant pressure and temperature. This mixture is of interest to $CO_2$ separation and recovery in Integrated Coal Gasification (IGCC) plants. The impact of tetrahydrofuran (THF) on hydrate formation from the $CO_2/H_2$ was observed. The addition of THF not only reduced the equilibrium formation conditions significantly but also helped ease the formation of hydrates. This study illustrates the concept and provides the basic operations of the separation/recovery of $CO_2$ (pre-combustion capture) from a fuel gas ($CO_2/H_2$) mixture.

• Journal of Korean Society of Rural Planning
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• v.14 no.2
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• pp.25-32
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• 2008

Wind energy, which is one of renewable energy, would be useful resources that can be applied to making energy recycling villages without using fossil fuels. This study analyzed energy potential on wind power considering weather condition in three rural villages and compared with energy consumption surveyed. A wind turbine system in the 5kW class can generate 26.1%, 73.9% and 39.5% of the yearly mean consumption of electric power per house in Makhyun, Boojang and Soso respectively. A 750kW wind turbine system can generate 1.7%, 30.3% and 22.1% of the total amount of electric power consumption in three study villages respectively. Wind power energy density was too low in Makhyun and Soso, so it is determined that the application of wind turbine system is almost impossible. Wind energy potential was generally low in Boojang either, but it is evaluated that there is a little possibility of wind power generation relatively. For practical application of renewable energy to rural green-village planning, assessment of energy potential for the local area should be preceded.

• Journal of Digital Convergence
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• v.11 no.2
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• pp.249-256
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• 2013

Recent days, the global warming problem due to excessive use of fossil fuels has been the world wide issue so that Korea government and developed countries make an alternative plan for eco-friendly and transportations by utilizing bicycles for health promotion. Existing Public Bicycle Rental Service Systems provide simple service such as bicycle rental management and tracking the location. However there is no user-side service for the information of the measure of carbon reduction, or use of bicycles. The proposed system in this paper provides users' health information, environmental information, personal information, counseling services and the measures of carbon reduction. The new system has been developed to carry out reducing carbon and growing green in terms of using bicycles by adopting Web 2.0 technology.

• Korean Journal of Computational Design and Engineering
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• v.20 no.2
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• pp.193-209
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• 2015

For reasons such as global warming, depletion of fossil fuels and the danger of nuclear energy the research and development of renewable energy is actively underway. Wind energy has advantages over another renewable energy in terms of location requirements, energy efficiency and reliability. Nowadays the research and development area is expanded to offshore because it can supply more wind reliability and free from noise pollution. In this study, the monopile offshore wind turbine transportation and installation (T&I) process are investigated. In addition, the schedule and cost for the process are estimated by discrete event simulation. For the simulation, simulation models for various means of T&I are developed. The optimum T&I execution plan with shortest duration and lowest cost can be found by using different mission start day and T&I means.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.228.2-228.2
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• 2010

In this work, the hydrogen production costs of the nuclear energy sources are estimated in the necessary input data on a Korean specific basis. G4-ECONS was appropriately modified to calculate the cost for hydrogen production of HTE process with Very High Temperature nuclear Reactor (VHTR) as a thermal energy source rather than the LUEC (Levelized Unit Electricity Cost). The general ground rules and assumptions follow G4-ECONS. Through a preliminary study of cost estimates, we wished to evaluate the economic potential for hydrogen produced from nuclear energy, and, in addition, to promptly estimate the hydrogen production costs for an updated input data for capital costs. The estimated costs presented in this paper show that hydrogen production by the VHTR could be competitive with current techniques of hydrogen production from fossil fuels if $CO_2$ capture and sequestration is required. Nuclear production of hydrogen would allow large-scale production of hydrogen at economic prices while avoiding the release of $CO_2$. Nuclear production of hydrogen could thus become the enabling technology for the hydrogen economy. The major factors that would affect the cost of hydrogen were also discussed.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.451-458
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• 2017

An Electric Vehicle (EV) is operated with the electric energy of a battery in place of conventional fossil fuels. Thus, a suitable charging infrastructure must be provided to expand the use of electric vehicles. Because the battery of an EV must be charged to operate the EV, expanding the number of EVs will have a significant influence on the power supply and demand. Therefore, to maintain the balance of power supply and demand, it is important to be able to predict the numbers of charging EVs and monitor the events that occur in the distribution system. In this paper, we predict the hourly charging rate of electric vehicles using transformation matrix, which can describe all behaviors such as resting, charging, and driving of the EVs. Simulation with transformation matrix in a specific region provides statistical results using the Monte-Carlo Method.

• Journal of the Korean Ceramic Society
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• v.55 no.3
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• pp.185-202
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• 2018

Photoelectrochemical (PEC) cells can convert solar energy, the largest potential source of renewable energy, into hydrogen fuel which can be stored, transported, and used on demand. In terms of cost competitiveness compared with fossil fuels, however, both photocatalytic efficiency and cost-effectiveness must be achieved simultaneously. Improvement of cost-effective, scalable, versatile, and eco-friendly fabrication methods has emerged as an urgent mission for PEC cells, and solution-based fabrication methods could be capable of meeting these demands. Herein, we review recent challenges for various nanostructured oxide photoelectrodes fabricated by solution-based processes. Hematite, tungsten oxide, bismuth vanadate, titanium oxide, and copper oxides are the main oxides focused on, and various strategies have been attempted with respect to these photocatalyst materials. The effects of nanostructuring, heterojunctions, and co-catalyst loading on the surface are discussed. Our review introduces notable solution-based processes for water splitting photoelectrodes and gives an outlook on eco-friendly and cost-effective approaches to solar fuel generation and innovative artificial photosynthesis technologies.

• Journal of Power System Engineering
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• v.13 no.6
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• pp.29-34
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• 2009

Recently, we have a lot interest in a sudden rise of oil prices and a change weather for the earth warmming, so, development of new alternative fuels need in order to spare fossil fuel and reduce exhaust emissions for air pollution prevention. Biodiesel, which can be generated from natural renewable sources such as new or used vegetable oils or animal fats, may be used as fuel in diesel engine of compression ignition engine. In this paper, the combustion characteristics between neat diesel oil and biodiesel blends(10 vol.% biodiesel and 20 vol.% biodiesel) were tested using four stroke, direct injection diesel engine, especially this biodiesel was produced from soybean oil at our laboratory. This analysis showed that cylinder pressures, the rate of pressure rises and the rate of heat releases were decreased as the blending ratios of biodiesel to diesel oil increased because of lower heating value of biodiesel in spite of increased oxygen content in biodiesel.

• Journal of the Korean Electrochemical Society
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• v.18 no.2
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• pp.86-94
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• 2015

In order to solve incoming environmental crisis and an energy crunch caused by the consumption of fossil fuels, lots of investigations and developments for solar cell application are getting a spotlight in various aspects. Amongst many solar cells, a flexible dye sensitized solar cell is an attractive research field from fundamentals to commercialization. In this manuscript, we introduce materials and available techniques for the future scientific research and technical developments in commercialization.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.3
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• pp.266-273
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• 2013

With the worldwide trend of controlling the utilization of fossil fuels inducing global climate change, many efforts will have to be made on securing a sustainable energy supply. Tidal current is a concentrated form of gravitational energy, its resource is significant, but limited locations. To effectively capture tidal current energy from the sea, a group of tidal turbines should be formed and positioned with optimal size and spacing for absorbing from multiple points. Thus, the flow field including turbines becomes a huge domain, a so-called tidal farm. It can be very convenient technically and economically if a whole turbine farm is simulated by means of actuator disc thoery. So, the analysis method using actuator discs coupled with a solution of Reynolds Averaged Navier-Stokes (RANS) equations is adopted for actual tidal turbines. Actuator discs have regions where similar forces imposed by actual turbines are applied to a flow. As working in group formation, turbines naturally have interaction effects on one another. Therefore, the present paper investigate the evaluation on the operating performance of tidal farm in terms of the mutual influence among turbine units with various lateral and longitudinal spacing. Authors expect that results of the present study contribute to the development of tidal farm for the future potential energy.