• Title/Summary/Keyword: 수증기-이산화탄소 개질

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Hydrogen Generation Characteristics of SMART System with Inherent $CO_2/H_2$ Separation ($CO_2/H_2$ 원천분리 SMART 시스템의 수소생산특성)

  • Ryu, Ho-Jung
    • Journal of Hydrogen and New Energy
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    • v.18 no.4
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    • pp.382-390
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    • 2007
  • To check the feasibility of SMART(Steam Methane Advanced Reforming Technology) system, an experimental investigation was performed. A fluidized bed reactor of diameter 0.052m was operated cyclically up to 10th cycle, alternating between reforming and regeneration conditions. FCR-4 catalyst was used as the reforming catalyst and calcined limestone(domestic, from Danyang) was used as the $CO_2$ absorbent. Hydrogen concentration of 98.2% on a dry basis was reached at $650^{\circ}C$ for the first cycle. This value is much higher than $H_2$ concentration of 73.6% in the reformer of conventional SMR (steam methane reforming) condition. The hydrogen concentration decreased because the $CO_2$ capture capacity decreased as the number of cycles increased. However, the average hydrogen concentration at 10th cycle was 82.5% and this value is also higher than that of SMR. Based on these results, we could conclude that the SMART system can replace SMR system to generate pure hydrogen without HTS (high tempeature shift), LTS (low temperature shift) and $CO_2$ separation process.

CO2 Capture from the Hydrogen Production Processes (수소생산 공정에서의 이산화탄소 포집)

  • Yeon Ki, Hong
    • Journal of Institute of Convergence Technology
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    • v.12 no.1
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    • pp.19-23
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    • 2022
  • Interest in hydrogen production to respond to climate change is increasing. Until now, hydrogen has been mainly produced through the SMR (Steam Methane Reforming) process using natural gas. A large amount of CO2 is emitted in the hydrogen production process through SMR, and the gas flow including CO2 generated in the SMR process has different characteristics for each emission source, so it is important to apply a suitable CO2 capture process. In the case of PSA tail gas or synthesis gas, the applicability of an amine-based process has been confirmed or demonstrated close to a commercial level. However, in the case of the flue gas generated from the reformer, it is still difficult to apply the conventional amine-based process because the partial pressure of CO2 is relatively low. Energy-saving innovative absorbents such as phase separation absorbents can be a solution to these difficulties.

Experimental Study of Hydrogen and Syngas Production over Ni/Ce-ZrO2/Al2O3 Catalysts with Additives (Ni/Ce-ZrO2/Al2O3 촉매의 첨가제에 따른 수소 및 합성가스 생성에 대한 실험적 연구)

  • Cho, Wonjun;Yu, Hyejin;Mo, Yonggi;Ahn, Whaseung
    • Journal of Hydrogen and New Energy
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    • v.25 no.2
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    • pp.105-113
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    • 2014
  • Performance tests on $Ni/Ce-ZrO_2/Al_2O_3$ catalysts with additives (MgO, $La_2O_3$) were investigated in the combined reforming processes (SCR, ATR, TRM) in order to produce hydrogen and carbon monoxide (it is called "syngas".). The catalyst characterization was conducted using the BET surface analyzer, X-ray diffraction (XRD), SEM, TPR and TGA. The combined reforming process was developed to adjust the syngas ratio depending on the synthetic fuel (methanol, DME and GTL) manufacturing processes. Ni-based catalysts supported on alumina has been generally recommended as a combined reforming reaction catalyst. It was found that both free NiO and complexed NiO species were responsible for the catalytic activity in the combined reforming of methane conversion, and the $Ce-ZrO_2$ binary support employed had improved the oxygen storage capacity and thermal stability. The additives, MgO and $La_2O_3$, also seemed to play an important role to prevent the formation of the carbon deposition over the catalysts. The experimental results were compared with the equilibrium data using a commercial simulation tool (PRO/II).

Reaction Characteristics of Combined Steam and Carbon Dioxide Reforming of Methane Reaction Using Pd-Ni-YSZ Catalyst (Pd-Ni-YSZ 촉매를 이용한 수증기-이산화탄소 복합개질 반응 특성)

  • Kim, Sung Su
    • Applied Chemistry for Engineering
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    • v.29 no.4
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    • pp.382-387
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    • 2018
  • In this study, the reaction characteristics of combined steam and carbon dioxide reforming of methane (CSCRM) reaction using Pd-Ni-YSZ catalyst were investigated according to types of catalysts and gas compositions. Catalysts were prepared in the form of powder and porous disk. The injected gases were supplied at different ratios of $CH_4/CO_2/H_2O$. As a result, the conversion of $CH_4$ and $CO_2$ was improved as a result of using the porous disc type catalyst as compared with that of the powder type catalyst. When the $CH_4/CO_2/H_2O$ ratio of the feed gas was 1 : 0.5 : 0.5, the $H_2/CO$ ratio was adjusted close to 2. However, after 6 hours of the reaction, $CH_4$ conversion was partially reduced by the carbon deposition and the pressure drop increased from 0.1 to 0.8. This issue was then solved by optimizing the water content. As a result, it was confirmed that the durability was secured by preventing the carbon deposition when the gas was supplied at a $CH_4/CO_2/H_2O$ ratio of 1 : 0.5 : 1, and the conversion rate was maintained at a relatively high level.

Characteristics of the Carbon Capture and Utilization System in Methanol Fuel Propulsion Ships Based on the Hydrogen Fuel Cell Hybrid System (수소 연료전지 하이브리드 시스템 기반 메탄올 연료추진 선박에서 CCU 적용에 따른 시스템 특성 분석)

  • YoonHo Lee;JunHo Kim
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.30 no.2
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    • pp.239-251
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    • 2024
  • In this study, a hydrogen fuel cell process based on methanol was developed to reduce greenhouse gas emissions. In Case1, the methanol fuel engine system was designed to investigate the emission of exhaust gas when methanol was supplied as fuel instead of gasoline to the engine. In Case2, a hydrogen fuel cell system was designed by adding a methanol reforming system to Case1. This hybrid system produced gray hydrogen and combined the output of the engine and fuel cell to drive the ship. However, gray hydrogen emits carbon in the process of producing hydrogen. To address this problem, a carbon capture and utilization (CCU) system was added to Case3. The CO2 of the flue gas discharged from Case2 was synthesized with gray hydrogen to produce blue methanol. The results of the case studies revealed that the optimal operating conditions were 220 ℃, 500 kPa, SCR = 1.0, and flow ratio = 0.7. The system of Case3 reduced carbon emissions by 42% compared with that Case1. Thus, the hybrid system of Case3 could considerably reduce the ship's CO2 emissions.

Optimization of DME Reforming using Steam Plasma (수증기 플라즈마를 이용한 DME 개질의 최적화 방안 연구)

  • Jung, Kyeongsoo;Chae, U-Ri;Chae, Ho Keun;Chung, Myeong-Sug;Lee, Joo-Yeoun
    • Journal of Korea Society of Industrial Information Systems
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    • v.24 no.5
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    • pp.9-16
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    • 2019
  • In today's global energy market, the importance of green energy is emerging. Hydrogen energy is the future clean energy source and one of the pollution-free energy sources. In particular, the fuel cell method using hydrogen enhances the flexibility of renewable energy and enables energy storage and conversion for a long time. Therefore, it is considered to be a solution that can solve environmental problems caused by the use of fossil resources and energy problems caused by exhaustion of resources simultaneously. The purpose of this study is to efficiently produce hydrogen using plasma, and to study the optimization of DME reforming by checking the reforming reaction and yield according to temperature. The research method uses a 2.45 GHz electromagnetic plasma torch to produce hydrogen by reforming DME(Di Methyl Ether), a clean fuel. Gasification analysis was performed under low temperature conditions ($T3=1100^{\circ}C$), low temperature peroxygen conditions ($T3=1100^{\circ}C$), and high temperature conditions ($T3=1376^{\circ}C$). The low temperature gasification analysis showed that methane is generated due to unstable reforming reaction near $1100^{\circ}C$. The low temperature peroxygen gasification analysis showed less hydrogen but more carbon dioxide than the low temperature gasification analysis. Gasification analysis at high temperature indicated that methane was generated from about $1150^{\circ}C$, but it was not generated above $1200^{\circ}C$. In conclusion, the higher the temperature during the reforming reaction, the higher the proportion of hydrogen, but the higher the proportion of CO. However, it was confirmed that the problem of heat loss and reforming occurred due to the structural problem of the gasifier. In future developments, there is a need to reduce incomplete combustion by improving gasifiers to obtain high yields of hydrogen and to reduce the generation of gases such as carbon monoxide and methane. The optimization plan to produce hydrogen by steam plasma reforming of DME proposed in this study is expected to make a meaningful contribution to producing eco-friendly and renewable energy in the future.

Life Cycle Assessment for Hydrogen Production Method using Stream Reforming of Naphtha (Naphtha의 stream reforming에 의한 수소제조방법에 대한 전과정평가)

  • Park, Hee-Il;Kim, Ik;Lee, Byung-Kwon;Hur, Tak
    • Journal of Hydrogen and New Energy
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    • v.13 no.1
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    • pp.3-12
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    • 2002
  • In this study, it achieved life cycle assessment to estimate environmental performance for naphtha steam reforming that account for the production over 50% of total hydrogen output. Although hydrogen dosen't emit air emissions, especially, $CO_2$, a large of $CO_2$ is emitted in hydrogen production process. In the result of this study, it ascertained the truth that $CO_2$ is emitted at the rate of $6.3kg/kgH_2$ and that result from steam reforming reaction and use of fossil fuel in hydrogen manufacturing process. Above all, 57% of total $CO_2$ emissions is emitted in process of steam reforming of naphtha and so it knew that the principle of steam reforming is key issue in aspect to environment. Also, it compared hydrogen by fuel of fuel cell vehicle with gasoline fuel of general gasoline vehicle to analyze relative environment of hydrogen for fossil fuel during the life cycle. As the result, it might be difficult in improvement of environment because $CO_2$ emissions during the hydrogen manufacturing process is nearly the same with that during the use of gasoline.