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        검색결과 716

        581.
        2015.11 서비스 종료(열람 제한)
        Steel slag has been used as the alternative binder to replace Portland cement that furthermore used as in construction and/or for stabilization/solidification of heavy metals in mine soil. One of the treatments to modify the leaching behavior of the mine soil is by carbonation. The purpose of this study was to assess the potential of carbonation in various steel slags. Based on chemical and mineralogical characterization of four kinds of slag that were used in this study, it showed that all slags had high potential for reacting with CO2 that was in accordance with the high CaO and MgO content. CO2 sequestration by aqueous carbonation of several kinds of stainless steel slags with different liquid to solid ratio was investigated in this study. The effect of chemical properties and reaction time on the performance of the carbonation process was also investigated. Converter slag, blast furnace slag (BFS) and ladle furnace slag (LFS) were used. Carbonation experiment was conducted in a closed reactor under the conditions; 1bar, 400rpm and 25℃, with solid to liquid ratios of 0.4, 0.6 and 1.0. Carbonation kinetic test was relatively fast and completed within 5 hours. The CO2 consumption increased when the liquid to solid ratio increased because of the dilution effect. Our results showed that the higher CaO and MgO contents in the slag, the higher CO2 consumption was observed. Pohang converter slag and Dangjin LFS showed slightly different tendency. At L/S ratio 0.4, Pohang slag with higher CaO and MgO content had higher CO2 consumption than Dangjin LFS. As the water content increased, Dangjin LFS had higher CO2 consumption than Pohang converter slag that was caused by the texture of Dangjin LFS with smaller particle size than Pohang converter slag. However, both Pohang BFS and Dangjin BFS have poor capacity in CO2 sequestration.
        582.
        2015.11 서비스 종료(열람 제한)
        우리나라는 1990년대부터 급속한 산업화와 인구증가로 도시 폐기물양이 증가하고 있다. 그 중 생활폐기물은 매립, 소각, 재활용 등의 방법으로 처리된다. 최근 국내 및 국외 선진국에서는 폐기물과 관련된 정책 및 패러다임을 갖고 최대한 폐기물을 자원순환으로 전환하고 이를 통해 매립처리량을 줄여 국토를 효율적으로 이용하는 방향으로 변모하고 있으며, 따라서 매립처리량이 줄어든 대신 재활용과 소각으로 처리되는 생활폐기물의 양이 증가하고 있다. 소각은 반입되는 폐기물의 약 90% 이상의 부피를 감소시켜 처리하는 것으로, 소각시 발생되는 소각재는 비산재와 바닥재로 나뉜다. 비산재는 소각재의 약 20%를 차지하며, 상대적으로 가볍고 다이옥신 및 유해 중금속성분들이 많아서 지정폐기물로 처리되고 있다. 반면 바닥재는 소각재의 약 80%를 차지하며, 대부분 일반폐기물로 매립 처리되고 있는 실정이다. 소각재 중 많은 양을 차지하고 있는 바닥재는 그 성분이 골재 및 자갈의 특성과 유사하다. 따라서, 여러 선진국에서는 바닥재를 도로건설의 경량 골재로 이용하거나 아스팔트 또는 콘크리트의 골재로 재이용하고 있고, 다른 재활용 제품으로의 사용을 위한 다양한 연구가 진행 중이다. 현재 우리나라에서도 정책적 방향에 따라 소각재를 콘크리트 및 건설자재로 재이용하기 위한 연구가 진행되고 있다. 국내에서는 바닥재를 재활용하기 위해서 “폐기물관리법 제14조의 3 제2항 [별표 5의2] 폐기물의 재활용 기준 및 구체적인 재활용 방법” 35항에 보면 바닥재를 재활용하기 위한 기준을 만족하도록 정하고 있다. 본 연구에서는 해당 기준에 있는 항목(강열감량, pH, 염소화합물, 시안화합물, 중금속 용출실험)들을 실험하여 평가하였으며, 기존의 전처리방법(세정, CO2 강제숙성)을 비교 실험하고, 세정+ CO2주입을 동시에 처리하는 방법을 이용하여 재활용기준을 만족하기 위한 최적 방법을 도출하고자 하였다.
        583.
        2015.05 서비스 종료(열람 제한)
        We carried out to investigate of CO2 reaction mechanism in oxy gasification reaction field. Capacity of gasification system is 0.5ton/day and that consists of feeder, gasification reactor assembled ash melting function, multi cyclone, wet scrubber, combustion chamber, heat exchanger, bag filter, ID fan and noncatalyst (steam reformer)/catalyst reformer. Gasification temperature was about 1,400~1,450℃ and RPF was used as a input material. We confirmed to possibility of Boudouard Reaction at the oxy gasification system. Boudouard Reaction is a reaction between carbon(soot) and carbon monoxide in the reaction field. We can find that the more Boudouard Reaction, the more residence time. For optimal reforming conditions such as temperature, amount of steam and residential time were investigated. It can be acquired that conditions of 45% H2 concentration and 3.0 H2/CO ratio in non-catalyst syngas reforming test and conditions of 60% H2 and 35% CO2 concentration in catalyst syngas reforming test.
        584.
        2015.05 서비스 종료(열람 제한)
        2010년 기준 온실가스 발생을 10% 저감하기 위해서는 11조원 이상의 비용이 발생할 것으로 추정하고 있다. 이러한 기후변화협약의 후속조치로 이산화탄소 배출저감을 위해 노력하고 있으며 장기적으로 에너지절약기술 추진, 청정에너지 이용확대, 첨단 환경기술개발, 이산화탄소 흡수원 확대 및 차세대 에너지 기술개발을 통하여 이산화탄소 배출을 줄이기 위한 혁신적인 계획을 제시하고 있다. 또한 저효율 에너지기기의 보급 확대, 대체연료 개발의 가속화, 풍력 및 태양광 발전의 개발, 메탄가스의 연료화 기술 및 장치개발 등이 거론되고 있으나, 이러한 기술접목에 따른 구체적인 이산화탄소 저감대책에 대한 환경적인 평가 등이 제대로 수립되지 못한 실정이다. 최근 정부에서도 저탄소 녹생성장을 국가의 추진동력으로 생각하고 있으며 이를 구체화하기 위한 일환으로 녹색마을 600개 시범사업 등을 통해서 저탄소 녹색도시를 그 대책의 일환으로 추진하고 있다. 이에 따라 국내 신재생에너지 기술개발도 기후변화협약에 대한 장기적인 대책으로 연구개발을 추진할 필요성이 있으며, 대체에너지 기술개발 등 기후변화협약에 능동적으로 대처할 수 있는 대응책이 필요하다. 이러한 상황에 대비하고 저탄소 녹색마을을 제도적으로 보급하기 위해서는 주민들에게 유효 에너지단위당 방출되는 온실효과 유발가스를 양으로 환산하여 에너지기술과 시스템을 비교하고 우열을 가릴 수 있도록 하는 새로운 저탄소녹색마을 기본설계방안을 연구 방안으로 강구되어야 할 것이다. 이러한 바이오매스를 적절히 에너지로 전환하는 경우 산업 및 농업시설에서의 냉난방용 에너지원으로, 더 나아가서는 녹색 마을단위의 에너지원으로 활용하여 농업생산력의 제고 및 국가차원의 대체에너지개발 및 온실가스 감축의 효과를 기대할 수 있을 것이다. 그러므로 저탄소 녹색도시의 성패는 신재생에너지 기술과 그 기술을 녹색마을에 어떻게 접목하는 가가 중요한 이슈가 될 것이다. 그 중에서도 바이오에너지의 경우는 녹색마을에서 쉽게 접목이 가능하고 이를 통해서 탄소중립소재를 활용하여 현재 사용하고 에너지원에서 발생하는 CO2배출량을 저감할 수 있는 방안으로 바이오에너지별 적용하고 져 한다. 따라서 본 논문에서는 경기도내에서 발생하는 바이오매스인 임산폐기물 및 축분 등의 바이오에너지원과 태양열 및 지열을 이용하여 전과정적으로 CO2발생량을 계산하고 이를 저탄소 녹색마을에 적용하는 데 있다. 이를 위하여 경기도내 P 도시의 년 CO2발생량을 산정하고 이를 토대로 바이오매스를 재활용한 대체에너지 등의 기술적용을 통하여 실제 CO2배출량을 저감할 수 있는 방안의 일환으로 연구를 시도하는 것이다.
        585.
        2015.05 서비스 종료(열람 제한)
        A simple in-situ biomethane system to upgrade biogas was developed by using differential solubility of biogas which normally contains 35-45% carbon dioxide (CO2) and 55-65% methane (CH4) by volume. The biomethane system consists of mesophilic plug-flow sorghum digester coupled with a leachate recycle loop to an external CO2 stripper. The leachate produced in the mesophilic plug-flow digester flows to the stripper where dissolved CO2 is removed. Then the leachate that CO2 was completely stripped out is recycled back to the plug-flow reactor, resulting in absorbing CO2 and enriched CH4 contents in digester offgas from the mesophilic plug-flow digester. Offgas CH4 contents was correlated well with leachate recycle rates and alkalinity. To maintain a biogas methane content over 95%, 3 volume of leachate recycle per volume of reactor per day(3 v/v-d) and at the reactor alkalinity of 4 g/L as CaCO3 was required. Even at an intermittent stripping ratio up to 3 hours stripping(N2 sweep gas 700 ml/min) and 1 hour no-stripping, the offgas methane content over 95% was achieved. It thus resulted in a 25% reduction in the total energy and sweep gas consumption. The TVS removal efficiency of the biomethane system was 80 percent which corresponded to 96% of the control reactor. The leachate recycle rates directly affected methane productivity that appeared to be 0.71 v/v-d at 3 volume of leachate recycle per volume of reactor per day(3v/v-d) and at the reactor alkalinity of 4 g/L as CaCO3.
        586.
        2015.04 서비스 종료(열람 제한)
        Many industries put emphasis on Environment-Friendliness as environmental problems are on the rise all over the world. Among themselves the Modular Bridge research is going on. Also performing cross-section optimization and duration reducing, this research aims at developing the modular bridge with Environment-Friendliness and economic feasibility. However, The difficulty lies in verifying environmental effectiveness because there is no field applications of the modular bridge until now. Therefore, this thesis is 40m bending steel girder modular bridge CO2 emission quantification per work type and materials according to each form to verify environmental effectiveness of the modular bridge.
        587.
        2014.11 서비스 종료(열람 제한)
        Biogas is a gaseous mixture produced from microbial digestion of organic materials in the absence of oxygen. Raw biogas, depending upon organic materials, digestion time and process conditions, contains about 45-75% methane, 30-50% carbon dioxide, 0.3% of hydrogen sulfide gas and fraction of water vapor. Pure methane has a caloric value of 34,400 kJ/m³, but the lower heating value of raw biogas changes between 13,720 and 27,440 kJ/m³. To achieve the standard composition of the biogas the treatment techniques like absorption must be applied. In this paper the experimental results of the methane purification in simulated biogas mixture consisted of methane, carbon dioxide and hydrogen sulfide were presented. The air-lift reactor is performed with MEA in order to increase the simultaneous purification for the gaseous mixtures of CO2 and H2S which are main components of the biogas. The effects of feed pressures and mixed gas on the separation of CO2-CH4 by membrane are investigated. It was shown that it was possible to achieve the purification of methane from the concentration of 55% up to 99%. The flow cell reactor was used to measure the reaction rate constant and to determine the optimal conditions of process for improving process efficiency.
        588.
        2014.10 KCI 등재 서비스 종료(열람 제한)
        Hydrochlorofluorocarbon (HCFC) is an ozone-depleting substance that is subject to environmental regulations based onthe Montreal Protocol, and in Republic of Korea, which is regarded as a developing country, its use will be restricted inphase starting in 2013 until finally being prohibited in 2030. HCFC is regulated Based on the Tokyo Protocol, HCFC isa regulated construction material for carbon dioxide reduction with GWP of 1,700~2,400 times that of CO2, with a GWPof 1. Using the CO2 in the heat insulating material in the extrusion process conditions are the first extruder, the polystyreneresin (melting point) and the blowing agent (CO2:Ethanol:HCFC) as interval (Mixing zone) which is the combinedpressure 11.0MPa, temperature 200oC, second within the extruder discharge pressure 6.5 MPa, and determines that it isdesirable to set the temperature of 115oC, the blowing agent mixing ratio (CO2:Ethanol:HCFC), taking into account thestability of the thermal conductivity of 30:20:50%, 25:25:50% is expected to be utilized in the foaming agent.
        589.
        2014.10 서비스 종료(열람 제한)
        Currently, global warming problem is serious. One of reasons of global warming is CO2 emissions. As an alternative means to prevent this, there is an environment-friendly effect of modular bridge method. After analyzing the CO2 emissions of the steel modular bridge which is used in a modular bridge based on D/B W.B.S analysis program and by comparing the CO2 emissions with that of the similar type of bridge, it is intended to analyze the environmental-friendly of modular bridge through the evaluation of the CO2 emissions of modular steel girder bridge of 21m.
        590.
        2014.09 KCI 등재 서비스 종료(열람 제한)
        In this work, the separation characteristics of CO2 from CO2 and CH4 mixed gas was studied using pressure swingadsorption (PSA) process. Zeolite 13X was used as an adsorbent to adsorb CO2 from gaseous stream in a fixed-bed ofadsorbent. The adsorption experiments were performed with various gas flow rates, adsorption pressures and temperatures.The deactivation model was used to analyze the adsorption kinetics of CO2 using the experimental breakthrough data.From this work, it was found that the activation energies of adsorption and deactivation were 29.15 and 13.0 kJ/mol,respectively. And the experimental breakthrough curves were agree very well with the adsorption isotherm models basedon Freundlich equation.
        591.
        2014.06 KCI 등재 서비스 종료(열람 제한)
        We examined the combined impacts of future increases of CO2 and temperature on the growth of four marine diatoms (Skeletonema costatum, Chaetoceros debilis, Chaetoceros didymus, Thalassiosira nordenskioeldii). The four strains were incubated under four different conditions: present (pCO2: 400ppm, temperature: 20℃), acidification (pCO2: 1000ppm, temperature: 20℃), global warming (pCO2: 400ppm, temperature: 25℃), and greenhouse (pCO2: 1000ppm, temperature: 25℃) conditions. Under the condition of higher temperatures, growth of S. costatum was suppressed, while C. debilis showed enhanced growth. Both C. didymus and T. nodenskioldii showed similar growth rates under current and elevated temperature. None of the four species appeared affected in their cell growth by elevated CO2 concentrations. Chetoceros spp. showed increase of pH per unit fluorescence under elevated CO2 concentrations, but no difference in pH from that under current conditions was observed for either S. costatum or T. nodenskioeldii, implying that Chetoceros spp. can take up more CO2 per cell than the other two diatoms. Our results of cell growth and pH change per unit fluorescence suggest that both C. debilis and C. didymus are better adapted to future oceanic conditions of rising water temperature and CO2 than are S. costatum and T. nodenskioeldii.
        592.
        2014.06 KCI 등재 서비스 종료(열람 제한)
        As global warming is higher by CO2, most of countries have an effort to develop CO2 reducing technology like a CO2 sequestration and a CO2 curing method using cement based materials. In this study, CO2 uptake rate and compressive strength were investigated when CO2 curing method was applied in cement mortar. The CO2 uptake rate was ranged from 10.1% to 11.6% by mass measurement method and from 6.2% to 16.3% by TGA method. This means that mass measurement method by electronic scale is more accurate than TGA method to estimate CO2 uptake rate. The early compressive strength of 1 hour CO2 curing specimens was higher than that of 1 hour atmospheric curing specimens, but lower than that of 5 hours steam curing specimens. 3 days and 7 days compressive strength of specimens by atmospheric curing and steam curing were increased both. But compressive strength of 1 hour CO2 curing specimens was lower than that of other two curing methods.
        593.
        2014.06 KCI 등재 서비스 종료(열람 제한)
        In this study, the variations of the carbon dioxide fluxes were investigated with soil temperatures in the grassplot and seasonal variations of carbon dioxide concentrations and fluxes were analysed. Soil temperatures, carbon dioxide concentrations and fluxes were measured on the grassplot in Pukyong National University. Field measurements were carried out 25 times from March in 2010 to March in 2011 with nine points on the grassplot. Seasonal variations of carbon dioxide concentrations and fluxes showed an inverse relation. In summer, carbon dioxide concentrations are lower and carbon dioxide fluxes are higher. In winter, carbon dioxide concentrations are higher and carbon dioxide fluxes are lower. On the grassplot, carbon dioxide emission rate increase when the soil temperature is more than 20℃ and the emission rate decrease when the soil temperatures are less than 10℃. When the accumulated rainfall for five days before measurement day is 20~100 mm, it is showed that the more rainfall, the more carbon dioxide emissions. Carbon dioxide emission rate from the grassplot to the upper atmosphere was increased or decreased by the factors such as soil temperature, growth and wither of grass and rainfall. The results of this study showed that the emission of carbon dioxide in the grassplot is dominantly controlled by seasonal factors (especially soil temperature and rainfall).
        594.
        2014.05 KCI 등재 서비스 종료(열람 제한)
        Industrial gas drying, dilute gas mixtures purification, air fractionation, hydrogen production from steam reformers and petroleum refinery off-gases, etc are conducted by using adsorptive separation technology. The pressure swing adsorption (PSA) has certain advantages over the other methods, such as absorption and membrane, that are a low energy requirement and cost-effectiveness. A key component of PSA systems is adsorbents that should be highly selective to a gas being separated from its mixture streams and have isotherms suitable for the operation principle. The six standard types of isotherms have been examined in this review, and among them the best behavior in the adsorption of CO2 as a function of pressure was proposed in aspects of maximizing a working capacity upon excursion between adsorption and desorption cycles. Zeolites and molecular sieves are historically typical adsorbents for such PSA applications in gas and related industries, and their physicochemical features, e.g., framework, channel structure, pore size, Si-to-Al ratio (SAR), and specific surface area, are strongly associated with the extent of CO2 adsorption at given conditions and those points have been extensively described with literature data. A great body of data of CO2 adsorption on the nanoporous zeolitic materials have been collected according to pressure ranges adsorbed, and these isotherms have been discussed to get an insight into a better CO2 adsorbent for PSA processes.
        595.
        2014.03 KCI 등재 서비스 종료(열람 제한)
        DNA damage such as genotoxicity was identified with comet assay, which blood cell of a marine parrot fish (Oplegnathus fasciatus) was exposed to an acidified seawater, lowered pH gradient making of CO2 gas. The gradient of pH were 8.22, 8.03, 7.81, 7.55 with control as HBSS solution with pH 7.4. DNA tail moment of fish blood cell was 0.548 ± 0.071 exposed seawater of pH 8.22 condition, on the other hand, DNA tail moment 1.601 ± 0.197 exposed acidified seawater of pH 7.55 lowest condition. The approximate difference with level of DNA damage was 2.9 times between highest and lowest of pH. DNA damage with decreasing pH was significantly increased with DNA tail moment on blood cell of marine fish (ANOVA, p < 0.001). Ocean acidification, especially inducing the leakage of sequestered CO2 in geological structure is a consequence from the burning of fossil fuels, and long term effects on marine habitats and organisms are not fully investigated. The physiological effects on adult fish species are even less known. This result shown that the potential of dissolved CO2 in seawater was revealed to induce the toxic effect on genotoxicity such as DNA breakage.
        596.
        2014.03 KCI 등재 서비스 종료(열람 제한)
        In this study, before and after sunset carbon dioxide concentration and air temperature were observed in two points of atmosphere (lower observation point of the GL + 0.1 m, the upper observation point of GL + 1.0 m) on the foreshore at located in Suncheon Bay and their variations were analyzed. Observation was performed on the foreshore on 2~4 August 2010. Instrument (VAISALA, GMP343) was set two hours before sunset and then observation was made continuously for six hours. In three days, observed carbon dioxide concentration was 375~419 ppm, and the air temperature was in the range of 28.7~32. 5℃. The average concentration of carbon dioxide was 388~399 ppm in the upper observation point and 386~396 ppm in the lower observation point. It was higher in the upper observation point and its fluctuations were similar in two observation points. Correlation coefficients between carbon dioxide concentration and air temperature in the upper observation point were in the range of –0.64~–0.88, and were calculated –0.65 to -0.90 in the lower observation point. For the carbon dioxide concentration, correlation coefficients between the upper part and the lower part were very high as 0.98 in three times. For the air temperature, correlation coefficients between the upper part and the lower part were very high as 0.97 and 0.99. In the same observation time, the slope of the linear regression function as carbon dioxide concentration in the lower observation point for the upper observation point was in the range of 0.97~1.01. Carbon dioxide concentration was slightly higher in the upper observation point. Because carbon dioxide in the lower observation point was closer on the surface of the foreshore and absorbed from atmosphere to the foreshore. In this study, it was showed that the vertical variation of carbon dioxide concentration was insignificant in the several meter scale of atmosphere on the surface of the foreshore.
        597.
        2014.03 KCI 등재 서비스 종료(열람 제한)
        폐콘크리트 처리 시 발생하는 시멘트 미분은 CO2 포집을 위한 광물탄산화 재료로 활용할 수 있다. 이번 연구에서는 폐콘크리트를 활용한 CO2 포집을 위한 기초연구로 수화시멘트의 수성탄산화 방안과 탄산염광물 형성 특성에 대한 자료를 확보하고자 하였다. 실험을 위해 물 : 시멘트 비를 6 : 4로 하여 28일간 수중 경화하여 시멘트 풀을 제작하고, 첨가제(NaCl과 MgCl2)를 활용한 용출실험과 두 종류의 수성탄산화(직접수성탄산화와 간접수성탄산화)실험을 수행하였다. 용출실험 결과, Ca2+ 이온의 용출은 시험된 최대 농도에서 보다 0.1 M NaCl과 0.5 M MgCl2에서 최대로 나타났으며, MgCl2는 NaCl에 비해 10배 이상의 Ca2+ 이온을 용출력을 보였다. 미분(< 0.15 mm)의 시멘트 풀은 직접수성탄산화에 의해 1시간 이내에 탄산화에 의해 포트랜다이트가 거의 모두 탄산염광물로 변화하고, CSH(calcium silicate hydrate)의 분해에 의한 탄산화도 진행되는 것으로 나타났다. 그러나 직접수성탄산화에는 NaCl과 MgCl2와 같은 첨가제가 크게 효율적이지 못하였다. NaCl과 MgCl2를 첨가제로 사용한 용출액에 대한 간접수성탄산화로 100% 순수한 방해석을 생성되었다. MgCl2에 의한 용출액의 경우 탄산화를 위해 알칼리용액 의한 pH의 조절이 필요하였으며, Mg2+ 이온의 영향으로 탄산화가 느리게 진행되었다. 수성탄산화 방법과 첨가제의 종류가 생성되는 탄산칼슘광물의 종류와 결정도 영향을 미치는 것으로 나타났다.
        598.
        2014.02 서비스 종료(열람 제한)
        지구온난화로 인한 재앙을 방지하기 위하여 온실가스 배출을 감축하려는 노력은 지속적으로 추진되어 왔다. 최근에는 이미 배출된 이산화탄소를 포집하고 격리하여 온실가스를 감축하려는 방안도 활발히 연구 되고 있는 실정이다. 이산화탄소의 격리 방법 중 이산화탄소를 지반 내에 영구히 저장하는 방안이 제안되어 연구되고 있다. 이산화탄소의 차폐성능이 확인된 지반에 이산화탄소를 주입하기 위하여 주입공을 건설하여야 한다. 일반적으로 이산화탄소 주입공은 대심도공내에 강재 케이싱을 삽입 하고 그 주위를 환체 시멘트를 이용하여 차폐하지만, 주입공 주위의 환체 시멘트는 저장된 이산화탄소의 누출 경로가 될 가능성이 매우 높다고 알려져 있다. 본 연구에서는 이산화탄소의 지반 내 격리를 위한 주입공의 내구성과 차폐성능 향상을 위한 환체 시멘트의 개질개선을 위한 기초적인 연구로 고온고압 하에서 양생된 환체 시멘트의 미세구조 특성을 분석하고자 한다. 유정용으로도 사용되는 Type G 시멘트를 대심도 지반상태인 고온고압 (80 °C, 10 MPa) 상태에서 28일간 양생하였다. 이를 위하여 고온고압의 양생환경을 구현하기 위한 실험장치가 개발되었다. 고압의 질소가스를 투입하여 압력을 높였으며, 히팅 자켓을 이용하여 양생 온도를 유지하였다. 다양한 미세구조 분석 장치를 사용하여 고온고압에서 양생된 시멘트의 미세구조의 구성성분과 기계적 성질을 파악하였다.
        599.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        Biogas from anaerobic digestion of biological wastes is a renewable energy resource. It has been utilized to provideheat and electricity. Raw biogas contains about 55~65% methane, 30~45% carbon dioxide, 0.5% of hydrogen sulfidegas and fraction of water vapor. The presence of CO2 and H2S in biogas affects less caloric value of raw biogas andcorrosion of engine etc.. Reducing CO2 and H2S contents improves a quality of fuel. In this paper, the absorption processusing aqueous monoethanol amine has been investigated as one of the leading technologies to purify the biogas. Liquidabsorbent is circulated through the reactor, contacting the biogas in countercurrent flow. The experimental results of themethane purification in simulated biogas mixture consisted of methane, carbon dioxide and hydrogen sulfide werepresented. It was shown that using aqueous solution used is effective in reacting with CO2 in biogas and it was possibleto achieve the purification of methane from the concentration of 55% up to 98%. This technique proved to be efficientin enriching and purifying of biogas, and has to be used to improve process efficiency.
        600.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        Carbon dioxide generated from construction materials and construction material industry among the fields ofconstruction is approximately 67 million tons. It is about 30% of the carbon dioxide generated in the fields of construction.In order to reduce carbon dioxide in the fields of construction, it is necessary to control the use of fossil fuel consumedand decrease carbon emission by reducing the secondary and tertiary curing generating carbon dioxide in constructionmaterial industry. Therefore, this study manufactured mortar by having cement as the base and substituting three bindingmaterials up to 50% and then adopted different curing methods to analyze congelation and strength characteristics. According to the result of strength characteristics by the types of binding materials and replacement ratio, the specimensubstituting ESA (Early Strength Admixture) and FPC (Fine Particle Cement) showed active strength improvement. Inparticular, the specimen substituting ESA as 25% indicated the greatest strength improvement, and as the number of curingincreased, the strength grew higher, too. And when the binding material was used by substitution, it showed strengthcharacteristics similar to or higher than the specimen conducting tertiary autoclave curing as the secondary steam curing.