배연가스 분석에 의한 가연성과 유기성폐기물을 혼합한 고형화연료 연소 특성평가

하상안(Sang-An, Ha) 유기성자원학회 2009 유기물자원화 Vol.17 No.3

본 연구는 가연성폐기물, 음식물폐기물 및 하수슬러지를 혼합하여 연료로 제조하여, 연소장치에서 다양한 연소조건에 따라 배출되는 배연가스를 분석하여 연소특성을 조사하였다. CO가스성분은 연소과정에서 불완전연소 부분을 평가하는 가스성분으로서, 연소장치의 실험조건이 온도 800℃와 공기비 2일 때 가장 낮게 발생하였다. CO2는 시료가 완전 연소되어 최종적으로 발생되는 부산물로서 연소조건이 가장 최적상태인 온도 800℃와 공기비 2일 때 가장 높은 농도가 발생하였다. SO2발생은 시료 중에 황 함유량이 높은 S.1에서 높게 나타났다. NOx는 질소성분이 높은 S.1시료와 온도 800℃의 조건에서 공기비 m=2의 조건에서 NOx의 발생이 높게 나타났다. HCl가스는 연소과정에서 산소의 촉매 반응을 통해서 분진이나 금속촉매물질과 반응하여 다이옥신류를 발생시키는 전구물질로서 분석결과에서 보면 시료의 Cl함유량이 많은 시료와 동일한 시료에서 온도 800℃와 공기비 2일 때가 가장 낮은 HCl의 농도가 발생되었다. NH3는 시료의 혼합비율과 온도조건보다는 공기비 2일 때 연소시작 3분 후에 가장 낮게 나타났으며, 연소온도 보다는 공기비가 NH3의 생성에 더 큰 영향을 미치는 것으로 나타났다. H2S발생은 시료의 황 함유량이 높은 S.1시료와 하수슬러지나 음식물쓰레기 혼합 비율이 높은경우 높게 나타났다. 연소실험에서 혼합비율에 따라서 제조된 S.1과 S.2의 시료를 연소한 결과 CxHy농도 무연탄연소시 발생농도와 비슷하게 나타남으로서, 성형하여 제조된 연료는 보조연료 및 주연료로서 가치가 있는 것으로 평가되었다 The main objective of this study is to investigate the characteristics of combustion by analyzing fuel gases from a combustion equipment with various combustion conditions for refuse-derived fuels (RDFs). CO gas is a parameter for indicating of incomplete combustion during a combustion process. The lowest CO gas was produced when the experiment conditions were m=2 under airfuel condition and 800℃. CO2 gas is a final product after complete combustions. The highest amount of CO2 gas was produced when the experiment conditions were m=2 under air-fuel condition and 800℃. The highest level of SO2 gas was produced in S.1 sample containing the highest sulfur. The highest level of NOx gas was produced in S.1 sample with the highest nitrogen content and air-fuel condition of m=2 under temperature of 800℃. HCl gas that is generated by reacting with metals catalyst through oxygen catalyst reaction during combustion process is a precursor of dioxin formation. The higher level of HCl gas was produced in the sample with higher chlorine content. The lowest level of HCl gas was produced when the experiment conditions were air-fuel condition of m=2 and 800℃. The lowest level of NH3 gas was generated when the experiment condition was m=2 under air-fuel condition and after 3 minutes. Air-fuel condition is more important to create NH3 gas than operating temperatures. Higher level of H2S gas was generated in S.1 sample with the higher sulfur content and was created in RDFs that contain higher mixture ratios of sewage sludge and food wastes. A result of combustion, gases and gases levels from the combustion of S.1 and S.2 were very similar to the combustion of a stone coal. As results of this research, when evaluating the feasibility of the RDFs, the RDFs could be used as auxiliary and main fuels.

개질기용 예혼합 버너의 화염형태 및 안정성 특성

이필형(Pil Hyong Lee),박봉일(Bong Il Park),조순혜(Soon Hye Jo),황상순(Sang Soon Hwang) 한국연소학회 2010 한국연소학회지 Vol.15 No.3

Fuel processing systems which convert fuel into rich gas (such as stream reforming, partial oxidation, autothermal reforming) need high temperature environment (600~1,000℃). Generally, anode-off gas or mixture of anode-off gas and LNG is used as input gas of fuel reformer. In order to make efficient and low emission burner system for fuel reformer, it is necessary to elucidate the combustion and emission characteristic of fuel reformer burner. The purpose of this study is to develop a porous premixed flat ceramic burner that can be used for 1~5 ㎾ fuel cell reformer. Ceramic burner experiments using natural gas, hydrogen gas, anode off gas, mixture of natural gas & anode off gas were carried out respectively to investigate the flame characteristics by heating capacity and equivalence ratio. Results show that the stable flat flames can be established for natural gas, hydrogen gas, anode off gas and mixture of natural gas & anode off gas as reformer fuel in the porous ceramic burner. For all of fuels, their burning velocities become smaller as the equivalence ratio goes to the lean mixture ratio, and a lift-off occurs at lean limit. Flame length in hydrogen and anode off gas became longer with increasing the heat capacity. In particular, the blue surface flame is found to be very stable at a very lean equivalence ratio at heat capacity and different fuels. The exhausted NOx and CO measurement shows that the blue surface flame represents the lowest NOx and CO emissions since it remains very stable at a lean equivalence ratio.

브라운 가스와 수증기 혼합연료의 화염특성에 관한 수치 해석적 연구

장동순 ( Dong Soon Jang ),신미수 ( Mi Soo Shin ),방건웅 ( Gun Woong Bahng ) 한국폐기물자원순환학회 2013 한국폐기물자원순환학회지 Vol.30 No.6

The stoichiometric gas from an advanced alkaline electrolysis process as developed by Yull Brown is called as HHO gas or Brown gas. By this process, two moles of H2 and 1mole of O2 gases are generated stoichiometrically in a wellpremixed state. Due to the fact that very clean fuel can be obtained relatively easily by the simple equipment of electrolysis, the research of this gas has been continuously performed, even though the criticism has been made by many researcher of this area. The main controversial argument is in that the use of high quality electrical energy is used again for the generation of another combustible fuel with less than 100% efficiency in its energy transform. In fact, since Brown gas exists in the state of a completely mixed state only with oxygen molecule, there is no time delay due to turbulent mixing occurring in practical combustion process. Therefore, the high reaction rate is likely to have a high chance of backfire. Further, since there is no inert material like nitrogen as in air, the flame temperature rises unnecessarily high. In order to prevent the backfire phenomenon, the increase of injection velocity of fuel nozzle causes the formation of very unstable long flame with good chance of flame lift-off. One of practical application methods, the co-combustion of Brown gas with other fuel like gasoline and LNG, etc has been reported in open literature in order not only to increase the combustion efficiency but also for the reduction of pollutant emission such as NOx. In order to control the negative aspect of flame characteristics of Brown gas, in this study, an novel method is employed by premixing Brown gas with water vapor and the co-combustion performance and characteristics has been studied numerically for a combustor operated for kiln drying method. To this end, a commercial code(STAR-CCM+7.06) has been employed with the program verification against operational data of kiln drying combustor and a parametric numerical calculation has been made with the change of the amount of water vapor in the fuel mixture of Brown gas and water vapor. The calculation results show that the combustion feature looks quite stable without showing any unstable flame feature like long thin flame and backfire. Further temperature and streamline contours with the amount of water vapor content look consistent and physically acceptable. This result suggests that the addition of water vapor in the Brown gas looks one of promising method for the use of Brown gas as clean fuel.

Well-to-wheel greenhouse gas emissions of battery electric vehicles in countries dependent on the import of fuels through maritime transportation: A South Korean case study

Choi, Wonjae,Song, Han Ho Elsevier 2018 APPLIED ENERGY Vol.230 No.-

<P><B>Abstract</B></P> <P>Well-to-wheel (WTW) analysis of battery electric vehicles (BEVs) has been mainly performed in the U.S., China, and Europe, which are countries that can produce sizable amounts of fuels or import additionally required fuels through land transportation. However, the situation characterizing these countries is far different from that of countries dependent on the import of fuels through maritime transportation, such as Japan, South Korea, and Taiwan, because the dependence on fuel imports through maritime transportation affects not only the energy mix but also the complexity and results of WTW analysis. In addition, determining the WTW greenhouse gas (GHG) emissions of driving BEVs in these countries is very important since these countries have large amounts of GHG emissions and strong interests in the widespread adoption of BEVs. Therefore, unlike previous studies, this study evaluates the WTW GHG emissions of BEVs in South Korea as an example of such countries. To perform WTW analysis of BEVs, comprehensive life cycle analyses of five power generation fuels (coal, natural gas, petroleum-based fuel, uranium, and bio heavy oil) are conducted. In addition, ten different power generation technologies and two different electric grids (mainland and the Jeju Island) in South Korea are analysed. The fuel economies of BEVs and conventional vehicles are also considered for evaluating the WTW GHG emissions. The result of this study shows that import processes commonly increase the life cycle GHG emissions of power generation fuels. The GHG emissions of natural gas from the upstream process are ∼40% higher than those of the U.S due to the liquefaction and regasification required for importing natural gas. However, although natural gas produces large amounts of GHG emissions from the upstream process, the electricity generated from natural gas still produces the lowest GHG emissions among the fossil fuels like other countries due to the high efficiency of combined cycle systems. The life cycle GHG emissions of electricity of the Korean mainland and Jeju are calculated to be 578 g CO<SUB>2</SUB> eq/kWh and 544 g CO<SUB>2</SUB> eq/kWh, respectively, which are higher than that of the EU and lower than that of the U.S. and China. Driving BEVs in South Korea was found to have advantages of 90–110 g CO<SUB>2</SUB> eq/km and 50–60 g CO<SUB>2</SUB> eq/km on average over driving internal combustion engine vehicles (ICEVs) and hybrid electric vehicles (HEVs), respectively, not only on the Korean mainland but also on Jeju Island. Because the GHG emissions from the upstream process of major power generation fuels and the life cycle GHG emissions of the electricity from major power generation technologies are determined in this study, these results are expected to be informative for other countries, which may have different detailed generation mixes, in similar situations.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A case of countries dependent on fuel imports via maritime transportation is studied. </LI> <LI> 5 power generation fuels, 10 generation methods, and 2 electric grids are analysed. </LI> <LI> Importing raises the GHG emissions of power generation fuels, especially natural gas. </LI> <LI> WTW GHG emissions of BEVs with each generation fuel and method are calculated. </LI> <LI> The average WTW GHG emissions of BEVs are lower than those of ICEVs and HEVs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Well-to-wheel greenhouse gas emissions of BEVs in countries dependent on the import of fuels through maritime transportation.</P> <P>[DISPLAY OMISSION]</P>

FUEL PERFORMANCE CODE COSMOS FOR ANALYSIS OF LWR UO2 AND MOX FUEL

BYUNG-HO LEE,구양현,JAE-YONG OH,Jin-SikCheon,YOUNG-WOOK TAHK,손동성 한국원자력학회 2011 Nuclear Engineering and Technology Vol.43 No.6

The paper briefs a fuel performance code, COSMOS, which can be utilized for an analysis of the thermal behavior and fission gas release of fuel, up to a high burnup. Of particular concern are the models for the fuel thermal conductivity, the fission gas release, and the cladding corrosion and creep in UO2 fuel. In addition, the code was developed so as to consider the inhomogeneity of MOX fuel, which requires restructuring the thermal conductivity and fission gas release models. These improvements enhanced COSMOS’s precision for predicting the in-pile behavior of MOX fuel. The COSMOS code also extends its applicability to the instrumented fuel test in a research reactor. The various in-pile test results were analyzed and compared with the code’s prediction. The database consists of the UO2 irradiation test up to an ultra-high burnup, power ramp test of MOX fuel, and instrumented MOX fuel test in a research reactor after base irradiation in a commercial reactor. The comparisons demonstrated that the COSMOS code predicted the in-pile behaviors well, such as the fuel temperature, rod internal pressure, fission gas release, and cladding properties of MOX and UO2 fuel. This sufficient accuracy reveals that the COSMOS can be utilized by both fuel vendors for fuel design, and license organizations for an understanding of fuel in-pile behaviors.

Gas Fueled 추진선박의 FGS Room 내 천연가스 누출시 방출특성 및 환기효율성 검토

강호근(Ho-keun Kang),김기평(Ki-pyoung Kim),박재홍(Jae-hong Park) 한국마린엔지니어링학회 2010 한국마린엔지니어링학회 학술대회 논문집 Vol.2010 No.10

According to the requirement of Res.MSC.285(86) for natural gas-fueled engine installations in ships, pump and compressor rooms should be fitted with effective mechanical ventilation system of the under pressure type, providing a ventilation capacity of at least 30 air changes per hour. It generally considered that gas leakage is more likely from a FGS room as compared to other places, where installed in many kind of machinery or equipments like gas supply high-pressure pipes, valves, flanges and etc. Furthermore, leaked gas may be dispersed in a short time in an enclosed space, especially a Fueled Gas Supply system Room (FGS), due to high pressure. However, the present requirement in Res.MSC.285(86) just considers the ventilating capacity of air changes per hour but the capacity of leaked gas. Hence, the current requirements may not meet effectively when enforcing the new propulsion systems as marine fuel. This study is conducted for the purpose of safety evaluation about the dispersion and ventilation efficiency, which is installed in a Fueled Gas Supply system (FGS) room of gas fueled ship. Especially, the effect of the exhaust fans placed in the upper chamber is focused in detail. Numerical predictions are performed to know the features of flow pattern and the diffusion of natural gas concentration.

연료전지 연료가스인 하수처리장 소화가스정제

이종규,전재호,박규호,최두성,박재영 한국수소및신에너지학회 2007 한국수소 및 신에너지학회논문집 Vol.18 No.2

The Tancheon wastewater treatment plant(WWTP) in Seoul using anaerobic digestion to reduce the outlet sludge produces anaerobic digester gas which contains 65% CH4 and 35% CO2. The gas purification equipment was installed and operated to use Anaerobic Digester Gas(ADG) as a fuel for molten carbonate fuel cell(MCFC). The processes consist of the desulfurizer and the adsorption tower to remove H2S and siloxane in the gas. The gas purification equipment removed virtually over 95% of H2S and over 99% of siloxane. Results has demonstrated that the fuel cell can produce electrical output and hot water with negligible air emissions of CO, NOx and SO2. The site provides the first opportunity in Korea for demonstrating Molten carbonate fuel cell(MCFC) which the digester gas was applied to the fuel gas.

Influence of gas-to-liquid fuel on the combustion and pollutant emission characteristics

Park, Su Han,Lee, Donggon,Lee, Chang Sik Professional Engineering Publishing Ltd 2014 Proceedings of the Institution of Mechanical Engin Vol. No.

<P>The purpose of this work was to investigate the combustion performance and the pollutant emission characteristics of gas-to-liquid fuel in a passenger car’s diesel engine. In order to perform this study, the test facilities were set up on a 1.6 l four-cylinder compression ignition diesel engine with a common-rail injection system. Gas-to-liquid fuel combustion under a high-engine-load condition was compared with conventional diesel and biodiesel derived from soybean oil. The performance test results revealed that the gas-to-liquid fuel shows more rapid ignition than diesel and biodiesel do because of its high cetane number. The rates of increase in the combustion pressure in gas-to-liquid fuel and biodiesel were smaller than that in diesel, and the maximum rate of heat release from gas-to-liquid fuel was the lowest among the three test fuels. In terms of emission analysis, gas-to-liquid fuel shows a slight decrease in the nitrogen oxide emissions and significant reductions in the hydrocarbon and the carbon monoxide emissions compared with other test fuels. Meanwhile, the combustion of gas-to-liquid fuel indicates a lower concentration of soot emissions than those from conventional diesel but slightly higher than those from biodiesel owing to the variation in the low heating value parameter.</P>

FUEL PERFORMANCE CODE COSMOS FOR ANALYSIS OF LWR UO₂ AND MOX FUEL

Lee, Byung-Ho,Koo, Yang-Hyun,Oh, Jae-Yong,Cheon, Jin-Sik,Tahk, Young-Wook,Sohn, Dong-Seong Korean Nuclear Society 2011 Nuclear Engineering and Technology Vol.43 No.6

The paper briefs a fuel performance code, COSMOS, which can be utilized for an analysis of the thermal behavior and fission gas release of fuel, up to a high burnup. Of particular concern are the models for the fuel thermal conductivity, the fission gas release, and the cladding corrosion and creep in $UO_2$ fuel. In addition, the code was developed so as to consider the inhomogeneity of MOX fuel, which requires restructuring the thermal conductivity and fission gas release models. These improvements enhanced COSMOS's precision for predicting the in-pile behavior of MOX fuel. The COSMOS code also extends its applicability to the instrumented fuel test in a research reactor. The various in-pile test results were analyzed and compared with the code's prediction. The database consists of the $UO_2$ irradiation test up to an ultra-high burnup, power ramp test of MOX fuel, and instrumented MOX fuel test in a research reactor after base irradiation in a commercial reactor. The comparisons demonstrated that the COSMOS code predicted the in-pile behaviors well, such as the fuel temperature, rod internal pressure, fission gas release, and cladding properties of MOX and $UO_2$ fuel. This sufficient accuracy reveals that the COSMOS can be utilized by both fuel vendors for fuel design, and license organizations for an understanding of fuel in-pile behaviors.

개질기용 예혼합 연소장치의 연소특성 연구

이필형(Pil Hyong Lee),이재영(Jae Young Lee),한상석(Sang Seok Han),박창수(Chang Soo Park),황상순(Sang Soon Hwang) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

Fuel processing systems which convert HC fuel into H₂ rich gas (such as stream reforming, partial oxidation, auto-thermal reforming) need high temperature environment(600-1000℃). Generally, anode-off gas or mixture of anode-off gas and LNG is used as input gas of fuel reformer. In order to make efficient and low emission burner system for fuel reformer, it is necessary to elucidate the combustion and emission characteristic of fuel reformer burner. The purpose of this study is to develop a porous premixed flat ceramic burner that can be used for 1-5㎾ fuel cell reformer. Ceramic burner experiments using natural gas, hydrogen gas, anode off gas were carried out respectively to investigate the flame characteristics by heating capacity and equivalence ratio. Results show that the stable flat flames can be established for natural gas, hydrogen gas, anode off gas and mixture of natural & anode off gas as reformer fuel. For all of fuels, their burning velocities become smaller as the equivalence ratio goes to the lean mixture ratio, and a lift-off occurs at lean limit. Flame length in hydrogen and anode off gas became longer with increasing the heat capacity.