• Transactions of the Korean hydrogen and new energy society
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• v.33 no.4
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• pp.309-317
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• 2022

There are 2,517 buses on 143 routes in Busan. One company is operating 36 hydrogen city buses (1.4%) and two hydrogen charging stations. By 2030, the number of hydrogen city buses will be increased to 500 and 40 hydrogen charging stations. In the survey of city bus companies, 61.5% of respondents answered 'not reviewing (at all)' and 23.0% of respondents '(actively) reviewing hydrogen buses'. And as for the level of help that hydrogen city buses give to bus companies, 23.5% answered 'helpful'. In order to promote the introduction of hydrogen city buses, first, it is necessary to stipulate support for hydrogen bus purchase cost and hydrogen charging station construction cost in related ordinances so that bus companies do not increase their burden of purchasing hydrogen buses in the future. Second, identify the number of new city buses introduced, convert about 50% to hydrogen city buses by the mid-term, and build 50% of the chargers in public garages with hydrogen chargers. Third, expand hydrogen refueling stations in city bus garages.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.4
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• pp.293-300
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• 2022

The Changwon city which announced 2040 hydrogen policy vision is planning to establish the new hydrogen-centered city. The building of plant which is available to produce the 5 ton/day of liquid hydrogen is promoted as one of the projects in order to achieve the vision. However, the analysis in terms of local economic and environmental aspects is insufficient because this liquid hydrogen plant is the first in Korea. Therefore, in this study, the financial feasibility of the liquid hydrogen plant project was analyzed by reviewing the benefits of liquid hydrogen supply and environmental improvement, and the feasibility of this project has been investigated which is being built based on the hydrogen industrial plan of Changwon city.

• New & Renewable Energy
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• v.17 no.4
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• pp.28-35
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• 2021

It is very important to secure hydrogen acceptability to achieve the hydrogen economy. This study empirically analyzed the factors affecting acceptance by using the results of a questionnaire administered to residents of Jeonju-Wanju Hydrogen Demonstration City. The results indicated that the safety of hydrogen infrastructure and local industry and economic growth positively affected acceptance. In particular, local industry and economic growth were more effective in improving resident acceptance. As policy factors, support for government policies and disclosure of information on projects were also positive factors. As perceptual factors, the higher interest in hydrogen and less safety concerns positively affected acceptability. Therefore, as far as hydrogen safety is concerned, it seems necessary to support local industry development to improve acceptability, disclose information related to industrial development, and introduce targeted experience programs.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.1
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• pp.15-20
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• 2015

During the liquefaction of hydrogen, the ortho hydrogen is converted into the para form with heat release that evaporates the liquefied hydrogen into the gaseous one backwards. The ortho-para conversion catalysts are usually used during liquefaction to avoid such boil-off. In order to compare and analyze the performance of the ortho-para hydrogen conversion catalysts, in-situ FT-IR device was designed and manufactured to measure the para hydrogen conversion rate in real-time. $LaFeO_3$ and $La_{0.7}Sr_{0.3}Cu_{0.3}Fe_{0.7}O_3$ perovskite catalysts were prepared by the citrate sol-gel method and their spin conversion characteristics from ortho to para hydrogen were investigated by in-situ FTIR spectroscopy at 17K. It was found that the spin conversion was affected by surface area, particle size, and crystallite size of the catalysts. Thus, the $La_{0.7}Sr_{0.3}Cu_{0.3}Fe_{0.7}O_3$ perovskite catalyst that had higher surface area, higher crystallite size, and smaller particle size than $LaFeO_3$ showed the better spin conversion property of 32.3% at 17K in 120min interaction with the perovskite catalysts.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.40-45
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• 1999

The effect of the addition of helium, neon, argon and xenon on the production of negative hydrogen ions has been studied in a magnetically confined dc filament discharge. The addition of helium and neon produced effects similar to an equivalent increase in hydrogen pressure. However, the addition of argon and low fractions of xenon produced significant increases in the negative ion density for hydrogen at pressures around 1 mTorr. The addition of argon and xenon, by increasing electron density and decreasing electron temperature, achieved conditions closer to optimum for negative ion production. The largest enhancement of negative hydrogen ion density occurred with the addition of argon; it is suggested that this is due to a resonant energy exchange between excited argon atoms and hydrogen molecules.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.6
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• pp.674-683
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• 2022

In this study, we examined the case of Fukushima Hydrogen Research Field (FH2R) Namie hydrogen town. We found that the case has three aspects of socio-technical experiment: a living-scale test-bed of hydrogen technologies, activities for enhancing social acceptability, and a designed module for policy transfer to diffuse. This study aims to provide a benchmark for planning a green hydrogen city in near future.

• Advances in Energy Research
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• v.5 no.2
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• pp.179-205
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• 2017

This research presents an in-depth analysis of location planning of the solar-hydrogen power plants for electricity production in different cities situated in Kerman province of Iran. Ten cities were analyzed in order to select the most suitable location for the construction of a solar-hydrogen power plant utilizing photovoltaic panels. Data envelopment analysis (DEA) methodology was applied to prioritize cities for installing the solar-hydrogen power plant so that one candidate location was selected for each city. Different criteria including population, distance to main road, flood risk, wind speed, sunshine hours, air temperature, humidity, horizontal solar irradiation, dust, and land costare used for the analysis. From the analysis, it is found that among the candidates' cities, the site of Lalezar is ranked as the first priority for the solar-hydrogen system development. A measure of validity is obtained when results of the DEA method are compared with the results of the technique for ordering preference by similarity to ideal solution (TOPSIS). Applying TOPSIS model, it was found that city of Lalezar ranked first, and Rafsanjan gained last priority for installing the solar-hydrogen power plants. Cities of Baft, Sirjan, Kerman, Shahrbabak, Kahnouj, Shahdad, Bam, and Jiroft ranked second to ninth, respectively. The validity of the DEA model is compared with the results of TOPSIS and it is demonstrated that the two methods produced similar results. The solar-hydrogen power plant is considered for installation in the city of Lalezar. It is demonstrated that installation of the proposed solar-hydrogen system in Lalezar can lead to yearly yield of 129 ton-H2 which covers 4.3% of total annual energy demands of the city.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.3
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• pp.234-240
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• 2015

In the face of the world's growing energy storage needs, liquid hydrogen offers a high energy density solution for the storage and transport of energy throughout society. A 5 L liquid hydrogen storage tank has been designed, fabricated and tested to investigate boil-off rate of liquid hydrogen. As the insulation plays a key role on the cryogenic vessels, various insulation methods have been employed. To reduce heat conduction loss, the epoxy resin-based insulation supports G-10 were used. To minimize radiation heat loss, vapor cooled radiation shield, multi-layer insulation, and high vacuum were adopted. Mass flow meter was used to measure boil-off rate of the 5 L cryogenic vessel. A series of performance tests were done for liquid nitrogen and liquid hydrogen to compare with design parameters, resulting in the boil-off rate of 1.7%/day for liquid nitrogen and 16.8%/day for liquid hydrogen at maximum.

• Membrane Journal
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• v.33 no.1
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• pp.46-51
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• 2023

The purpose of this study is to analyze the utilization forms of hydrogen fuel cells, which are the core of building a smart city, and suggest ways to solve them. In the case of power plants to utilize hydrogen fuel cell, it was analyzed as the most promising form of use in the future due to the advantage of being free from intermittence problems. However, despite many advantages, local residents' opposition continues to emerge due to concerns about explosions and the problem of carbon dioxide generation in the case of certain hydrogen production methods, and it is analyzed that resolving them will be the main key to establishing the smart city. Finally, by analyzing the current hydrogen production method and identifying the problems facing it, the solution for the complete construction of the smart city was presented.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.6
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• pp.469-480
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• 2019

This study was conducted to evaluate the degradation and mineralization of PPCPs (Pharmaceuticals and Personal Care Products) using a CBD(Collimated Beam Device) of UV/H₂O₂ advanced oxidation process. The decomposition rate of each substance was regarded as the first reaction rate to the ultraviolet irradiation dose. The decomposition rate constants for PPCPs were determined by the concentration of hydrogen peroxide and ultraviolet irradiation intensity. If the decomposition rate constant is large, the PPCPs concentration decreases rapidly. According to the decomposition rate constant, chlortetracycline and sulfamethoxazole are expected to be sufficiently removed by UV irradiation only without the addition of hydrogen peroxide. In the case of carbamazepine, however, very high UV dose was required in the absence of hydrogen peroxide. Other PPCPs required an appropriate concentration of hydrogen peroxide and ultraviolet irradiation intensity. The UV dose required to remove 90% of each PPCPs using the degradation rate constant can be calculated according to the concentration of hydrogen peroxide in each sample. Using this reaction rate, the optimum UV dose and hydrogen peroxide concentration for achieving the target removal rate can be obtained by the target PPCPs and water properties. It can be a necessary data to establish design and operating conditions such as UV lamp type, quantity and hydrogen peroxide concentration depending on the residence time for the most economical operation.