• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.583_584
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• 2009

본 논문은 난방에너지부문에 통합수요관리정책을 추진할 경우의 효과를 분석하기 위해서 난방기술별 비교우위 및 난방방식간의 전환효과를 분석하였다. 냉방공급방식으로는 전기냉방, 가스냉방, 빙축열 냉방을 채택하였으며, 동일한 냉방서비스 공급에 대한 1차에너지소비량, 이산화탄소배출량, 그리고 연료비용을 비교분석하였다. 또한, 에너지원별 에너지가격정책에 따른 가격왜곡현상의 유무에 따른 영향을 시나리오에 기초하여 분석하였다. 본 연구의 시나리오 분석을 통해, 전기냉방수요의 20%를 가스냉방수요로 전환할 경우에 연간 3,141억원의 사회적 편익이 발생할 수 있음을 확인하였다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.414-415
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• 2012

Reforming catalyst of synthesis gas for GTL-FPSO process is presented in this paper. In the present study, the Ni foam catalyst was compared with the existing $Al_2O_3$ pellet catalyst. The SCR reaction on the catalyst was evaluated at the different temperature. The $CH_4$ conversions increased with the reactor temperature. Also, the Ni foam catalyst had a higher $CH_4$ conversion than a pellet catalyst.

• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.285-290
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• 2013

Recently a novel bio refinery process with using nonedible biomass, especially microalgae, has been developed in order to directly reduce $CO_2$ concentration from flue gas and simultaneously produce renewable bio fuel. Micro algae-to-biofuel processes are composed of microalgae cultivation, harvesting, lipid extraction, and bio fuel conversion. So, there are concerns about the energy efficiencies of bio refinery processes. In this study, the net energy ratio of microalgae processes were calculated for the microalgae produced from a pilot photobioreacto using $CO_2$ released from coal combustion. In this study, trans-esterification and pyrolysis processes were used to analyze the net energy efficiencies. Micro algae-to-biofuel processes might produce bio fuels with the higher energy than that of the total consumed energy for cultivation, harvesting, extraction and conversion. If the lipid content of microalgae was higher, the trans-esterification conversion process was more effective than that of pyrolysis process.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.712-717
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• 2015

In this study, the experiment of CO production was performed using carbon dioxide and coal. The synthesis characteristics of CO gas was investigated using the chemical activation method of KOH. The preparation process has been optimized through the analysis of experimental variables such as activating chemical agents to coal ratio, the flow rate of gas and reaction temperature during $CO_2$ conversion reaction. Without the catalyst of KOH, the 66.7% of $CO_2$ conversion was obtained at the conditions of $T=950^{\circ}C$ and $CO_2$ flow rate of 300 cc/min. On the other hand, the 98.1% of $CO_2$ conversion was obtained using catalyst of KOH at same conditions. It was found that the feed ratio(Coal : KOH = 4 : 1) had better $CO_2$ conversion and CO selectivity than other feed ratios.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.322-322
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• 2013

$CO_2$를 $CH_4$와 열 및 전기화학적인 반응을 통해 고농도의 CO 및 $H_2$로 구성된 합성가스로 효율적으로 전환시키기 위해, 반응가스 주입용 간극형 노즐을 가진 비이송식 직류 열플라즈마 토치 시스템을 설계, 제작하고 다양한 조건에서 이 두 가스의 개질 실험을 수행하였다. 설계 제작된 간극형 노즐과 리액터 내 고온 반응 영역을 활용한 $CO_2$ 및 $CH_4$ 반응가스의 효율적인 처리를 통하여, 최고 70% 이상의 $CO_2$ 및 $CH_4$의 전환율과 최고 80% 이상의 CO 및 $H_2$선택도를 달성할 수 있음을 확인하였다. 또한, 상기 조건의 경우, 플라즈마 입력 전력 10.6 kW 대비 49 lpm 의 반응가스 처리량을 통하여 얻은 것으로 최고 2.5 mmol/kJ 이상의 Specific Energy Requirement (SER) 조건도 만족할 수 있음을 보였다. 특히, 제안된 막대 음극-반응 가스 주입구를 가진 양극 노즐 플라즈마 토치의 경우, $CH_4$ 반응가스를 음극에 직접 닿지 않도록 간극을 통해 주입하게 함으로써, 반응 가스 분해에 의한 음극 등 전극 부식을 최소화하면서도 고에너지 전자가 풍부한 아크 컬럼에 의해 $CO_2$ 및 $CH_4$의 전환 반응을 효율적으로 일으킬 수 있어 효율적인 $CO_2$ 및 $CH_4$ 개질을 위한 열플라즈마 토치 시스템의 개발이 기대된다.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.5
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• pp.528-532
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• 2007

The generation of high-purity hydrogen from hydrocarbon fuels is essential for efficient operation of fuel cell. In general, most feasible strategies to generate hydrogen from hydrocarbon fuels consist of a reforming step to generate a mixture of $H_2$, CO, $CO_2$ and $H_2O$(steam) followed by water gas shift(WGS) and CO clean-up steps. The WGS reaction that shifts CO to $CO_2$ and simultaneously produces another mole of $H_2$ was carried out in a two-stage catalytic conversion process involving a high temperature shift(HTS) and a low temperature shift(LTS). In the WGS operation, gas emerges from the reformer is taken through a high temperature shift catalyst to reduce the CO concentration to about $3\sim4%$ followed to about 0.5% via a low temperature shift catalyst. The WGS reactor was designed and tested in this study to produce hydrogen-rich gas with CO to less than 0.5%.

• Journal of the Society of Disaster Information
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• v.14 no.3
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• pp.288-295
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• 2018

Purpose: The paper aims to compare the effectiveness of the two types of transport demand management measures, namely pull measures and push measures. Method: Case studies of two metropolitan areas in the developing world assess the extent to which increases in fuel prices can contribute to reducing automobile use and increasing the public transport use and the potential of urban rail transit to cause mode shift from automobiles. Within the case studies, a stated response survey of current car users has been conducted for Cairo and an on-line survey of rail transit users in Algiers. Results: There was a major proportion of car drivers who intend to switch to public transport, depending on the range of fuel prices in Cairo and a considerable proportion of rail users who have switched from automobiles resulting in a measurable reduction in CO2 emissions in Algiers. Conclusion: Investments in urban rail can be highly effective where there are demands for better public transport, but this type of pull measures can be much more effective if combined with push measures which significantly raise driving costs.

• Clean Technology
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• v.28 no.1
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• pp.9-17
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• 2022

Electrochemical carbon dioxide (CO₂) reduction technology, one of the promising solutions for climate change, can convert CO₂, a representative greenhouse gas (GHG), into valuable base chemicals using electric energy. In particular, carbon monoxide (CO), among various candidate products, is attracting much attention from both academia and industry because of its high Faraday efficiency, promising economic feasibility, and relatively large market size. Although numerous previous studies have recently analyzed the GHG reduction potential of this technology, the assumptions made and inventory data used are neither consistent nor transparent. In this study, a comparative life cycle assessment was carried out to analyze the potential for reducing GHG emissions in the electrochemical CO production process in a more transparent way. By defining three different system boundaries, the global warming impact was compared with that of a fossil fuel-based CO production process. The results confirmed that the emission factor of electric energy supplied to CO₂-electrolyzers should be much lower than that of the current national power generation sector in order to mitigate GHG emissions by replacing conventional CO production with electrochemical CO production. Also, it is important to disclose transparently inventory data of the conventional CO production process for a more reliable analysis of GHG reduction potential.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.705-708
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• 2001

Enzymatic synthesis and purification of sugar esters using supercritical $CO_2$ were investigated. The observed yield of suagr ester produced by transesterification of methyl glucoside and oleic acid using a lipase(Novozym 435) was 67% at 24 hours of reaction in the supercritical $CO_2$. The solubility of the fatty acids in the supercritical $CO_2$ was measured to find the conditions of supercritical separation of the fatty acids from the reaction mixture. The solubility of capric and oleic acid was 5 ${\times}$ $10^{-4}$, 1.7 ${\times}$ $10^{-4}$ mol/mol $CO_2$, respectively, varying at $35{\sim}50^{\circ}C$ and 80${\sim}$120 atm.

• Journal of the Korean Institute of Gas
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• v.5 no.4 s.16
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• pp.27-32
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• 2001

It is desired that carbon dioxide causing a greenhouse effect be removed at a high temperature and high pressure in a steam reforming reaction. In this research, a pellet form of adsorbent CaO is employed to capture $CO_2$. The adsorbent was manufactured using a high pressure molding on powdered $CaCO_3$ followed by calcination. Then its properties were analyzed and the adsorption experiments were carried out in a batch adsorption chamber. The pore area was found to be dependent on a molding pressure and the pore distribution showed two peaks. It is examined that $CO_2$ binds to CaO by means of chemisorption and its maximum conversion is nearly $80\%$ at $700^{\circ}C$.