• Environmental and Resource Economics Review
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• v.21 no.2
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• pp.237-269
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• 2012

This study applies a discrete-continuous choice model to a national survey data set of automobile uses to investigate the potential impacts of a bonus-malus system for new cars in Korea. Not only the impacts on the discrete choice of automobile type and class but also those on the continuous decision making of car operation are analyzed. The characteristics of automobiles and individuals that determine car choice and operation are identified. The simulation based on the estimation result shows that an appropriately designed bonus-malus system can induce a reduction in energy consumption and $CO_2$ emission substantially without additional government expenditure.

• Applied Chemistry for Engineering
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• v.34 no.3
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• pp.291-298
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• 2023

This research evaluates the sustainability of gasifying livestock manure to produce fuel gas from an economic and carbon emission perspective. The entire process, including gasification, fuel gas purification, and pipeline installation to transport the produced fuel gas to the demanding industrial complex, is analyzed for realistic feasibility. The study is conducted using an ASPEN PLUS simulation with experimental data. The results of the economic and CO₂ life cycle assessments confirm that the fuel gas produced from livestock manure is competitive with natural gas despite having a lower calorific value. When used as a fuel with a high hydrogen content, the fuel gas emits less CO₂ per calorific value, making it more environmentally friendly. A scenario analysis is also performed to determine the expected economics, with price competitiveness being influenced by several factors. Although a significant decrease in natural gas prices could reduce the price competitiveness of the proposed process, it can still be supported by government policies. The cash flow analysis also confirms the economic viability of the process.

• Journal of the Korean Institute of Gas
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• v.27 no.4
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• pp.78-84
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• 2023

Recently, the world's countries are tightening regulations on CO2 and air pollutants emission to solve them. In addition, eco friendly vehicles is increasing to replace automobiles in internal combustion engine. The government is supporting the expansion of hydrogen refueling infrastructure according to the hydrogen economy road map. In particular, refueling station is important to secure the safety that supplies high-pressure hydrogen with a wide LFL range. This paper is on guidelines for the determination safety distances to ensure worker safety from accident as jet fire. The safety distance is set according to the procedure of the EIGA doc 075/21. For accident frequency is upper 3.5E-05 per annum, safety distance is decided via consequence analysis where the risk of harm is below individual harm exposure threshold.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.4
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• pp.181-190
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• 2008

To response climate change and Kyoto protocol and to reduce greenhouse gas emissions, marine geological storage of $CO_2$ is regarded as one of the most promising option. Marine geological storage of $CO_2$ is to capture $CO_2$ from major point sources(eg. power plant), to transport to the storage sites and to store $CO_2$ into the marine geological structure such as deep sea saline aquifer. To design a reliable $CO_2$ marine geological storage system, it is necessary to perform numerical process simulation using thermodynamic equation of state. The purpose of this paper is to compare and analyse the relevant equations of state including ideal, BWRS, PR, PRBM and SRK equation of state. To evaluate the predictive accuracy of the equation of the state, we compared numerical calculation results with reference experimental data. Ideal and SRK equation of state did not predict the density behavior above $29.85^{\circ}C$, 60 bar. Especially, they showed maximum 100% error in supercritical state. BWRS equation of state did not predict the density behavior between $60{\sim}80\;bar$ and near critical temperature. On the other hand, PR and PRBM equation of state showed good predictive capability in supercritical state. Since the thermodynamic conditions of $CO_2$ reservoir sites correspond to supercritical state(above $31.1^{\circ}C$ and 73.9 bar), we conclude that it is recommended to use PR and PRBM equation of state in designing of $CO_2$ marine geological storage process.

• Economic and Environmental Geology
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• v.45 no.5
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• pp.589-597
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• 2012

Recently, an understanding of new sources of liquid hydrocarbons such as bioethanol is economically very important. Bioethanol is actually ethyl alcohol or also referred to as ethanol, identical to drinking alcohol by its composition. There are mainly two ways of producing ethanol, namely by synthesis of hydrocarbons and from biomass. Only the second approach deserves the terminology 'bioethanol'. The present dissertation is also designed with purpose of developing the energy-saving process for the separation of bioethanol. The world population is expected to grow past 8 billion by 2030 which are almost 60% in Asia Pacific. History has shown that energy use rises much faster than population expands. World wide demand for energy will increase significantly during the next 15 years driven by population growth and the transition of emerging markets into the global economy. In developing nations, a smaller increment in GDP per capita yields a higher increment in energy consumption compared to developed countries. In this study, we analised total 2,454 dissertations for the bioethanol during the 2001~2012 periods by the programs of 'web of science' and 'recently developped program by Korea Institute of Science Technology Information'.

• Journal of the Korean Wood Science and Technology
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• v.45 no.5
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• pp.588-598
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• 2017

Currently, bioethanol, a fuel additive for transportation, is produced mainly by using biomass (first generation) such as corn and sugar canes. First generation biomass can cause various problems in terms of increase in agricultural prices and ethical reasons. To address these problems, a nonedible lignocellulosic biomass can be utilized. Agricultural byproducts such as straw, bagasse, and forest byproducts from the wood processing industry. Therefore, production of wood based bioethanol can be an effective utilization route of second generation biomass, and its raw materials are more abundant than first generation resources. Furthermore, it is possible to secure cheap raw materials. One of the biggest advantages of using biofuels is that it contributes to the reduction of greenhouse gases by minimizing the environmental impact, unlike fossil fuels. In this study, we investigated the greenhouse gas reduction effects that can be achieved through the use of Lignocellulosic bioethanol and government policies on renewable energy currently being implemented in ASEAN countries (Indonesia, Malaysia, Thailand and the Philippines). In these four countries, policies and incentives related to biofuels have been developed. It is expected that the reduction ratio of carbon dioxide emission and the mixed biofuel will be gradually increased in the future.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.4
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• pp.323-329
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• 2017

Nowadays, considering global warming and enhanced prohibition to discharge pollutants at sea, all of existing operation-ships must lead to the reduction of fuel consumption. International standards of International Maritime Organization and EU rules governing harbor pollutants are being strengthened. Therefore, ship-owners and operators are seeking ways to reduce $CO_2$, SOx, and NOx emissions. Although world trade continues to expand, total fuel usage for sea transport tends to diminish. However, ICS(International Chamber of Shipping) has set a goal of reducing $CO_2$ emissions from shipping by 50% until 2050. In addition, with respect to the Paris Climate Change Accord in 2015, IMO proposes to set up a reduction target of GHG emission from existing operation-ships. For setting up a reduction target of GHG from international maritime transport, "A data collection system for fuel consumption" will be introduced in the near future. In order to effectively reduce the use of fuel in a ship in accordance with the trend of compulsory fuel saving from operation ships, this paper suggested adoption of an Incentive-Penalty scheme based on Emission-Trading-Scheme, Carbon Tax, and basic calculation formula after verifying the EEOI level for a year.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.163-163
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• 2010

중적외선 영역 ($3{\sim}5\;{\mu}m$)은 공기 중에 존재하는 이산화탄소나 수증기에 의해 흡수가 일어나지 않기 때문에 군사적으로 중요한 파장 영역이며, 야간에 적을 탐지하는데 응용되고 있다. InSb는 77 K에서 중적외선 파장 흡수에 적합한 밴드갭 에너지 (0.228 eV)를 갖고 있으며, 다른 화합물 반도체와 달리 전하 수송자 이동도 (전자: $10^6\;cm^2/Vs$, 정공: $10^4\;cm^2/Vs$)가 매우 빠르기 때문에 적외선 화상 감지기 재료로 매우 적합하다. 또한 현재 중적외선 영역대에서 널리 사용되는 HgCdTe (MCT)와 대등한 소자 성능을 나타냄과 동시에 낮은 기판 가격, 소자의 제작 용이성 때문에 MCT를 대체할 물질로 주목 받고 있다. 하지만, 기판과 절연막의 계면에 존재하는 결함 때문에 에너지 밴드갭 내에 에너지 준위를 형성하여 높은 누설 전류 특성을 보인다. 따라서 InSb 적외선 소자의 구현을 위하여 고품질의 절연막의 연구가 필수적이라고 할 수 있겠다. 절연막의 특성을 알아보기 위해, n형 InSb 기판에 플라즈마 화학 기상 증착법 (PECVD)을 이용하여 $SiO_2$, $Si_3N_4$를 증착하였으며, 증착 온도를 $120^{\circ}C$에서 $240^{\circ}C$까지 $40^{\circ}C$ 간격으로 변화하여 증착온도가 미치는 영향에 대하여 알아보았다. 절연막과 기판의 계면 특성을 분석하기 위하여 77 K에서 커패시턴스-전압 (C-V) 분석을 하였으며, 계면 트랩 밀도는 Terman method를 이용하여 계산하였다 [1]. $Si_3N_4$를 증착하였을 경우, $120{\sim}240^{\circ}C$의 증착 온도에서 $2.4{\sim}4.9{\times}10^{12}\;cm^{-2}eV^{-1}$의 계면 트랩 밀도를 가졌으며, 증착 온도가 증가할수록 계면 트랩 밀도가 증가하는 경향을 보였다. 또한 모든 증착 온도에서 flat band voltage가 음의 전압으로 이동하였다. $SiO_2$의 경우 $120{\sim}200^{\circ}C$의 증착온도에서 $7.1{\sim}7.3{\times}10^{11}\;cm^{-2}eV^{-1}$의 계면 트랩 밀도 값을 보였으나, $240^{\circ}C$ 이상에서 계면 트랩밀도가 $12{\times}10^{11}\;cm^{-2}eV^{-1}$로 크게 증가하였다. $SiO_2$ 절연막을 사용함으로써, $Si_3N_4$ 대비 약 25% 정도 낮은 계면 트랩 밀도를 얻을 수 있었으며, 모든 증착 온도에서 양의 전압으로 flat band voltage가 이동하였다. 두 절연막에 대한 계면 트랩의 원인을 분석하기 위하여 XPS 측정을 진행하였으며, 깊이에 따른 조성 분석을 하였다. 본 실험에서 최적화된 $SiO_2$ 절연막을 이용하여 InSb 소자의 pn 접합 연구를 진행하였다. Be+ 이온 주입을 진행하고, 급속열처리(RTA) 공정을 통하여 p층을 형성하였다. -0.1 V에서 16 nA의 누설 전류 값을 보였으며, $2.6{\times}10^3\;{\Omega}\;cm^2$의 RoA (zero bias resistance area)를 얻을 수 있었다.

• Journal of Korea Port Economic Association
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• v.25 no.4
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• pp.1-20
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• 2009

Green logistics is regarded as an inevitable global trend in the 21st century. It can be accomplished through more broad and active reverse logistics globally, resulting in use of less fossil fuels, finally reducing carbon dioxide and other pollutants. Many countries such as U.S., Japan, EU nations have already set up policies related to carbon reduction, so-called 'green policies.' This paper aims to identify evaluation criteria for logistics policies and relative importance among those criteria, especially in the field of ports and in-land hub terminals. We examined projects related to carbon reduction from domestic and foreign ports and logistics centers and found evaluation factors and assessment indicators. With pre-evaluative items and pre-assessment indicators, we have done a survey and selected evaluation factors and assessment indicators for ports and inland hub terminals in Korea. By analyzing the mutual importance of each pre-evaluative items and pre-assessment indicators related to carbon reduction policies, this research provides guidelines on selecting the key items for the propulsion of carbon reduction projects. This study shows the importance of preliminary evaluation items and indexes with AHP in evaluating carbon reduction policies and the result shows the restrictions and change in transportation and use of alternative fuels. Lastly, it provides a guideline to policy-makers and firm managers in the field of green logistics.

• Membrane Journal
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• v.32 no.5
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• pp.292-303
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• 2022

An eco-friendly energy conversion device without the emission of pollutants has gained much attention due to the rapid use of fossil fuels inducing carbon dioxide emissions ever since the first industrial revolution in the 18th century. Polymer electrolyte membrane fuel cells (PEMFCs) that can produce water during the reaction without the emission of carbon dioxide are promising devices for automotive and residential applications. As a key component of PEMFCs, polymer electrolyte membranes (PEMs) need to have high proton conductivity and physicochemical stability during the operation. Currently, perfluorinated sulfonic acid-based PEMs (PFSA-PEMs) have been commercialized and utilized in PEMFC systems. Although the PFSA-PEMs are found to meet these criteria, there is an ongoing need to improve these further, to be useful in practical PEMFC operation. In addition, the well-known drawbacks of PFSA-PEMs including low glass transition temperature and high gas crossover need to be improved. Therefore, this review focused on recent trends in the development of high-performance PFSA-PEMs in three different ways. First, control of the side chain of PFSA copolymers can effectively improve the proton conductivity and thermal stability by increasing the ion exchange capacity and polymer crystallinity. Second, the development of composite-type PFSA-PEMs is an effective way to improve proton conductivity and physical stability by incorporating organic/inorganic additives. Finally, the incorporation of porous substrates is also a promising way to develop a thin pore-filling membrane showing low membrane resistance and outstanding durability.