• Bulletin of the Korean Chemical Society
• /
• 제19권8호
• /
• pp.825-830
• /
• 1998

The electrocatalytic reduction of dioxygen by Co(TTFP)(Y)2 {Y=H2O or HO-} is investigated by cyclic voltammetry, spectroelectrochemistry, hydrodynamic voltammetry at a glassy carbon electrode in dioxygen-saturated aqueous solutions. Electrocatalytic reduction of dioxygen by CoⅡ(TTFP)(Y)2 establishes a pathway of 2e- reduction to form hydrogen peroxide, and then the generated hydrogen peroxide is reduced to water by CoⅠ(TTFP)(Y)2 at more negative potential. CoⅡ(TTFP)(Y)2 may bind dioxygen to produce the adduct complex [CoⅡ-O2 or CoⅢ-O2] which exhibits a Soret band at 411 nm and Q band at 531 nm.

• 한국전자거래학회지
• /
• 제15권3호
• /
• pp.163-181
• /
• 2010

최근 온난화 현상에 따른 범세계적 위기가 초래됨에 따라 선진국을 중심으로 교토의정서가 체결되었으며, 이를 계기로 온실가스 규제가 본격화되기 시작하였다. 또한 교토의정서의 교토유연성체계라는 시장메커니즘이 도입되어 온실가스 배출에 대한 소유권이 설정되고, 수급에 따라 배출권 가격이 형성되는 등 새로운 무형의 자원을 거래하는 탄소시장이 등장하게 되었다. 학계에서는 탄소배출효과를 측정하는 방법론과 이를 탄소배출권의 경제적 비용으로 전환하고자 하는 연구들이 태동하기 시작하였다. 본 연구에서는 전자정부 정보화사업 중 하나인 G2B 시스템을 통해 전통적인 조달업무 프로세스가 온라인화 됨에 따라 저감되는 탄소 배출저감효과 즉, e-transformation화에 따른 탄소저감효과를 측정하는 ECRE(Evaluation of $CO_2$ Reduction in E-transformation)모델과 절차를 제시하고자 한다. ECRE 모델은 세계 기후협의체(IPCC)의 방법론을 근간으로 하여 크게 '이동 수단에 따른 탄소저감효과', '종이 문서 절감에 따른 탄소저감효과' 2가지의 탄소배출량을 측정하고 이를 탄소배출권의 경제적 비용으로 환산한다. 또한 본 연구에서는 탄소저감효과를 효과적으로 측정하기 위하여 5단계와 10개의 세부절차로 구성된 절차를 제시하였다. 본 연구에서 제시한 ECRE 모델과 절차를 이용하여 정부기관은 물론 온실가스 규제를 받게 되는 에너지 환경기업 등에서 정보화사업을 통한 탄소감축 실적의 추정 및 추가적인 정보화사업 추진으로 기대되는 탄소저감효과를 사전에 시뮬레이션해 볼 수 있는 도구로서 활용이 기대된다.

• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2008년도 하계학술발표대회 논문집
• /
• pp.1117-1121
• /
• 2008

Recently energy consumption and $CO_2$ emission issue are important problem on international society. The present study has been conducted economic analysis considering economical value of $CO_2$ reduction effect. We analyze annual energy cost and annual $CO_2$ emission of the cogeneration system and gas boiler system in hotel. The first results shows that annual energy cost of cogeneration system (751,740,126 won) is more profitable than gas boiler system (801,128,408 won) by 6.2% (49,388,281 won). The second results shows that annual $CO_2$ emission of cogeneration system (3,297 ton) is less than gas boiler system (3,536 ton) by 6.8% (239 ton). The Economical value of $CO_2$ reduction effect is 4,773,898 won. The cost effect according to the reduction of $CO_2$ is corresponding to 9.7% of reduction cost for total energy cost. The result of this study means that $CO_2$ reduction effect is essential item in introduction and change of facility for economic analysis.

• KIEAE Journal
• /
• 제14권2호
• /
• pp.87-98
• /
• 2014

This study is to identify quantitatively the function of carbon dioxide emissions reduction due to temperature and energy reduction according to direct carbon dioxide storage, shade provision, and evaportanspiration of urban park. According to the result of study, landscape tree indicated high carbon dioxide storage effect compare to bush, in which broadleaf tree indicated higher storage function than coniferous tree. It is believed to be the storage of carbon dioxide can be increased by increasing the composition rate of forest plants in the urban park. According to the direct estimation result of carbon dioxide storage in terms of example area, storage of carbon dioxide is estimated to be "seoul a zone" $476,818.8kg{\cdot}CO_2/m^2yr$, "anyang b zone" $186,435.7{\cdot}CO_2/m^2yr$, "daejeon c zone" $262,826{\cdot}CO_2/m^2yr$, "kwangju d zone" $231,657.8{\cdot}CO_2/m^2yr$. The carbon dioxide storage per unit area estimated to be "seoul a zone" $3.4{\cdot}CO_2/m^2yr$, "anyang b zone" $5.0{\cdot}CO_2/m^2yr$, "daejeon c zone" $2.6{\cdot}CO_2/m^2yr$, "kwangju d zone" $5.6{\cdot}CO_2/m^2yr$. The result of indirect carbon dioxide reduction effect estimated to be "seoul a zone" $291,603.4{\cdot}CO_2/m^2yr$, "anyang b zone" $165,462.4{\cdot}CO_2/m^2yr$, "daejeon c zone" $141,719.2{\cdot}CO_2/m^2yr$, "kwangju d zone" $154,803.4{\cdot}CO_2/m^2yr$. Carbon dioxide reduction potential amount through the urban park was increased to 1.6 times to 1.8 times when calculated to the indirect effect.

• 환경영향평가
• /
• 제8권4호
• /
• pp.59-72
• /
• 1999

The purpose of the study is to propose the concrete and realistic alternative measures for $CO_2$ emission reduction on commercial sector. To achieve the purpose, this study adopted AIM/KOREA simulation model modified from AIM(Asia-Pacific Integrated Model) originally developed by Japan National Environmental Research Institute. The results of simulation demonstrate that the $CO_2$ emission from the commercial sector in 1995 was estimated 864 million TC(tons of carbon); however, according to the base scenario, $CO_2$ emission in 2020 is expected to be increased to 1,872 million TC, which is 2.17 times greater than that in 1995. In order to mitigate the ever-increasing $CO_2$ emission, the results of AIM/KOREA simulations under various scenarios showed that the 30-thousand-won carbon tax scenario does not successfully motivate the selection of advanced technology; however, with the 300-thousand-won carbon tax, a substantial amount of $CO_2$ emission reduction by 1.69 million TC from the BaU((Business-as-Usual)scenario is expected to be achieved by year 2020. Such substantial reduction of $CO_2$ emission under the 300-thoudsand-won carbon tax scenario is due to the introduction of advanced technology, such as use of condensing boilers, forced by heavier carbon tax. Under the scenario that presumes the maximum introduction of gas-burning industrial appliances, an 2.66 million TC of $CO_2$ reduction was expected. The results of this study suggest that the $CO_2$ emission reduction measures can be interpreted in many different views. However, if people and industries are fully aware of the economic benefit of energy saving, a certain level of $CO_2$ reduction by a successful introduction of advanced energy saving technology appears to be achieved without carbon tax or subsidies.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
• /
• pp.2921-2927
• /
• 2011

Modal Shift from road to rail has been adapted in several countries as one of effective ways of reducing $CO_2$ emissions caused by transport. Generally, effect analysis of $CO_2$ reduction toward modal shift is calculated mainly from use stage and less consideration from other stages of life cycle, even though, in some case of modal shift needs that new line construction or new vehicle manufacturing. In this study, modal shift effect analysis is performed with considering construction, manufacturing vehicle and use stage. As a result we can get total $CO_2$ reduction effect using life cycle thinking and check the necessity of including other life cycle stage not only considering use stage. In conclusion, there is no $CO_2$ reduction effect if the reduction amount of $CO_2$ in use stage is not bigger than allocated annual amount of $CO_2$ in construction and manufacturing vehicle stage. According to this fact, analysing $CO_2$ reduction effect of Modal Shift should be considered not only the use stage.

• 한국세라믹학회지
• /
• 제55권4호
• /
• pp.381-391
• /
• 2018

In this work, photocatalytic $CO_2$ reduction over a CdSe-graphene-$TiO_2$ nanocomposite has been studied. The obtained material was successfully fabricated via ultrasonic technique. The physical properties of the as-synthesized materials were characterized by some physical techniques. The $TiO_2$ and CdSe dispersed graphene nanocomposite showed excellent results of strong reduction rates of $CO_2$ compared to the results of bare $TiO_2$ and binary CdSe-graphene. An outstanding point of the combination of CdSe-$TiO_2$ and graphene appeared in the form of great photocatalytic reduction capability of $CO_2$. The photocatalytic activity of the asfabricated composite was tested by surveying for the photoreduction of $CO_2$ to alcohol under UV and visible light irradiation, and the obtained results imply that the as-prepared CdSe-graphene-$TiO_2$ nanocomposite is promising to become a potential candidate for the photocatalytic $CO_2$ reduction.

• 한국재료학회지
• /
• 제33권2호
• /
• pp.29-46
• /
• 2023

The electrochemical reduction of carbon dioxide (CO₂) to value-added products is a remarkable approach for mitigating CO₂ emissions caused by the excessive consumption of fossil fuels. However, achieving the electrocatalytic reduction of CO₂ still faces some bottlenecks, including the large overpotential, undesirable selectivity, and slow electron transfer kinetics. Various electrocatalysts including metals, metals oxides, alloys, and single-atom catalysts have been widely researched to suppress HER performance, reduce overpotential and enhance the selectivity of CO₂RR over the last few decades. Among them, single-atom catalysts (SACs) have attracted a great deal of interest because of their advantages over traditional electrocatalysts such as maximized atomic utilization, tunable coordination environments and unique electronic structures. Herein, we discuss the mechanisms involved in the electroreduction of CO₂ to carbon monoxide (CO) and the fundamental concepts related to electrocatalysis. Then, we present an overview of recent advances in the design of high-performance noble and non-noble singleatom catalysts for the CO₂ reduction reaction.

• 청정기술
• /
• 제30권3호
• /
• pp.188-194
• /
• 2024

이 연구는 환원 온도 변화가 코발트-망간(CM) 기반 촉매의 구조와 성능에 미치는 영향을 조사하며, 이산화탄소(CO₂)의 직접 수소화 반응에서 촉매의 역할에 중점을 두고 있다. CM 촉매는 350 ℃의 환원 온도에서 CO₂를 장쇄 탄화수소로 성공적으로 전환하는 것으로 관찰되었다. 이러한 효율은 촉매의 코어-쉘 구조가 제공하는 최적의 조건에 기인하며, 이는 역수성가스전환(Reverse Water-Gas Shift, RWGS)과 피셔-트롭쉬(Fischer-Tropsch, FT) 반응을 모두 효과적으로 반응한다. 그러나 환원 온도가 섭씨 600 ℃까지 상승하면 이러한 효과적인 반응 과정이 방해받아 메탄으로 선택성이 전환된다. 이러한 변화는 고온에서 촉매의 표면이 과도하게 환원되어 RWGS 부위가 감소하고 결과적으로 CO 생성이 억제되기 때문에 발생한다. 이러한 연구 결과는 코발트 기반 촉매의 설계 및 최적화에서 환원 온도를 제어하는 것이 중요하다는 점을 강조하며 환원 온도조절을 통한 RWGS와 FT 반응 간의 균형 잡힌 상호 작용을 유지하는 것이 중요하다.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
• /
• pp.227-234
• /
• 2004

For gaseous fuel combustion with inherent $CO_2$ capture and low NOx emission, chemical-looping combustion(CLC) may yield great advantages of savings of energy to $CO_2$ separation and suppressing the effect on environment. In chemical-looping combustor, fuel is oxidized by metal oxide medium (oxygen carrier particle) in a reduction reactor. Reduced particles are transported to oxidation reactor and oxidized by air and recycled to reduction reactor. The fuel and the air are never mixed, and the gases from reduction reactor, $CO_2$ and $H_2O$, leave the system as separate stream. The $H_2O$ can be easily separated by condensation and pure $CO_2$ is obtained without any loss of energy for separation. The purpose of this study is to demonstrate inherent $CO_2$ separation and no NOx emission and to confirm high $CO_2$ selectivity, no side reaction (i.e., carbon deposition, hydrogen generation) by continuous reduction and oxidation experiment in a 50kWtb chemical-looping combustor. NiO/bentonite particle was used as a bed material and $CH_4$ and air were used as reacting gases for reduction and oxidation respectively.