• 제목/요약/키워드: Carbon Conversion

검색결과 708건 처리시간 0.026초

수소가스화기에서 석탄의 메탄화 반응 특성 (Characteristics of Coal Methanation in a Hydrogasifier)

  • 이시훈;윤상준;최영찬;김재호;이재구
    • Korean Chemical Engineering Research
    • /
    • 제44권6호
    • /
    • pp.631-635
    • /
    • 2006
  • 석탄의 수소가스화 반응에 따른 합성천연가스(substitute natural gas, SNG) 제조 특성을 고찰하기 위하여 연속식 lab-scale 분류층 수소가스화기(지름 : 0.025 m, 높이 : 1.0 m)를 이용하였다. 수소가스화 시스템은 고압 가스 주입부, 석탄 주입시스템, 분류층 수소가스화 반응기, 미반응물 분리장치로 이루어졌다. 실험은 반응온도 $600{\sim}800^{\circ}C$, 수소/석탄비 0.2~0.4, 석탄주입량 0.8~2.5 g/min의 범위에서 수행되었다. 6종류의 석탄시료를 사용한 실험결과로부터 반응온도가 증가하면 메탄화에 의한 탄소 전환율은 증가하였지만 증가하는 경향은 석탄의 종류에 따라서 각각 다르게 나타났다. 또한 수소/석탄비가 증가할수록 탄소 전환율이 증가하는 반면, 메탄농도는 감소함을 보였다. 석탄 시료 중에 포함된 탄소함량이 증가할수록 탄소 전환율이 증가하였으며, 석탄중 휘발분 함량이 35 wt%일 때 최대의 탄소전환율을 얻을 수 있었다.

백금담지 촉매의 직접메탄올 연료전지 환원전극 적용 (Application of Pt/C (60 wt.%) on electrode catalyst layer of direct methanol fuel cell)

  • 조용훈;조윤환;박현서;정남기;성영은
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 한국신재생에너지학회 2007년도 춘계학술대회
    • /
    • pp.188-190
    • /
    • 2007
  • The MEA with the catalyst layer containing PtRu black and 60 wt. %Pt/C as their anode and cathode catalysts. For find to effect of carbon support, the MEA with platinum black for cathode catalyst was fabricated. The performance of the MEA with the catalyst layer containing (PtRu black:60 wt.% Pt/C) as their anode and cathode catalyst has shown competitively higher value than the performance of the MEA with the catalyst layer containing (PtRu black:Pt black) as their anode and cathode catalyst.

  • PDF

상압 플라즈마-촉매 하이브리드 반응기를 통한 CO2와 CH4의 전환처리 (Conversion of CO2 and CH4 through Hybrid Reactor Composed of Plasma and Catalyst at Atmospheric Pressure)

  • 김태경;누엔덕바;이원규
    • 공업화학
    • /
    • 제25권5호
    • /
    • pp.497-502
    • /
    • 2014
  • 상압 플라즈마 반응기 내에 Ni-$Al_2O_3$와 Ni-$MgAl_2O_4$ 촉매를 충진한 하이브리드 반응기를 이용하여 메탄과 이산화탄소의 전환반응을 진행하였다. 인가전력, 반응가스 유량, 혼합비율 및 반응기 온도 등 다양한 공정변수와 촉매의 충진 유무에 따른 메탄과 이산화탄소의 전환반응 특성이 분석되었다. 촉매의 반응 기여도 분석에서 공정온도를 $400^{\circ}C$까지 올린 경우에도 플라즈마 방전이 없이는 메탄과 이산화탄소의 촉매를 통한 자발적 전환반응이 일어나지 않았다. 이는 촉매를 충진하지 않은 플라즈마 방전만의 전환공정과의 비교를 통하여 확인할 수 있었다. 플라즈마 반응기에 촉매를 적용하는 경우에는 공정의 적절성과 전환처리에 적합한 촉매의 선택이 필수적이다.

Pyrolysis kinetics and microstructure of thermal conversion products on toluene soluble component from two kinds of modified pitch

  • Zhu, Yaming;Zhao, Xuefei;Gao, Lijuan;Cheng, Junxia
    • Carbon letters
    • /
    • 제28권
    • /
    • pp.38-46
    • /
    • 2018
  • Modified pitch A (MPA) and modified pitch B (MPB) were prepared by oxidative polymerization and thermal polycondensation reaction with refined pitch as the raw material, respectively. The toluene soluble components (TS-1 and TS-2) were obtained by solvent extraction from MPA and MPB, separately. The Flynn-Wall-Ozawa method and Kissinger-Akahira-Sunose method were used to calculate the pyrolysis activation energy of TS. The Satava-Sestak method was used to investigate the pyrolysis kinetic parameters of TS. Moreover, the optical microstructure of the thermal conversion products (TS-1-P and TS-2-P) by calcination shows that TS-1-P has more contents of mosaic structure and lower contents of fine fiber structure than TS-2-P. The research result obtained by a combination of X-ray diffraction and the curve-fitting method revealed that the ratios of ordered carbon crystallite (Ig) in TS-1-P and TS-2-P were 0.3793 and 0.4417, respectively. The distributions of carbon crystallite on TS-1-P and TS-2-P were calculated by Raman spectrum and curve-fitting analysis. They show that the thermal conversion product of TS-2 has a better graphite crystallite structure than TS-1.

Assessing Organic Matter and Organic Carbon Contents in Soils of Created Mitigation Wetlands in Virginia

  • Ahn, Changwoo;Jones, Stacy
    • Environmental Engineering Research
    • /
    • 제18권3호
    • /
    • pp.151-156
    • /
    • 2013
  • Several soil properties were studied from three young created mitigation wetlands (<10 years old), which were hydrologically comparable in the Piedmont region of Virginia. The properties included soil organic matter (SOM), soil organic carbon (SOC), pH, gravimetric soil moisture, and bulk density ($D_b$). No significant differences were found in the soil properties between the wetlands, except SOM and SOC. SOM and SOC indicated a slight increase with wetland age; the increase was more evident with SOC. Only about a half of SOC variability found in the wetlands was explained by SOM ($R^2$ = 0.499, p < 0.05). The majority of the ratios of SOM to SOC for these silt-loam soils ranged from 2.0 to 3.5, which was higher than the 1.724 Van Bemmelen factor, commonly applied for the conversion of SOM into SOC in estimating the carbon storage or accumulation capacity of wetlands. The results may caution the use of the conversion factor, which may lead to an overestimation of carbon sequestration potentials of newly created wetlands. SOC, but not SOM, was also correlated to $D_b$, which indicates soil compaction typical of most created wetlands that might limit vegetation growth and biomass production, eventually affecting carbon accumulation in the created wetlands.

매체순환식 가스연소기용 산소공여입자들의 연료별 연소특성 (Reduction Characteristics of Oxygen Carrier Particles for Chemical-looping Combustor with Different Fuels)

  • 류호정;김경수;박영성;박문희
    • 한국수소및신에너지학회논문집
    • /
    • 제20권1호
    • /
    • pp.45-54
    • /
    • 2009
  • Reduction reactivity and carbon deposition characteristics of three oxygen carrier particles(OCN01, OCN02, OCN03) have been investigated by using hydrogen, methane, syngas, and natural gas as fuels. For all particles, the maximum conversion, the oxygen transfer capacity, and the degree of carbon deposition increased as the reactive carbon contents increased. The reduction rate and the oxygen transfer rate increased as the moles of required oxygen per input gas increased. The change of maximum conversion, reduction rate, oxygen transfer capacity, oxygen transfer rate and degree of carbon deposition for different fuels can be explained consistently by using parameters such as the reactive carbon contents and the moles of require oxygen per input gas.

Nano-structured Carbon Support for Pt/C Anode Catalyst in Direct Methanol Fuel Cell

  • Choi Jae-Sik;Kwon Heock-Hoi;Chung Won Seob;Lee Ho-In
    • 한국분말재료학회지
    • /
    • 제12권2호
    • /
    • pp.117-121
    • /
    • 2005
  • Platinum catalysts for the DMFC (Direct Methanol Fuel Cell) were impregnated on several carbon supports and their catalytic activities were evaluated with cyclic voltammograms of methanol electro-oxidation. To increase the activities of the Pt/C catalyst, carbon supports with high electric conductivity such as mesoporous carbon, carbon nanofiber, and carbon nanotube were employed. The Pt/e-CNF (etched carbon nanofiber) catalyst showed higher maximum current density of $70 mA cm^{-2}$ and lower on-set voltage of 0.54 V vs. NHE than the Pt/Vulcan XC-72 in methanol oxidation. Although the carbon named by CNT (carbon nanotube) series turned out to have larger BET surface area than the carbon named by CNF (carbon nanofiber) series, the Pt catalysts supported on the CNT series were less active than those on the CNF series due to their lower electric conductivity and lower availability of pores for Pt loading. Considering that the BET surface area and electric conductivity of the e-CNF were similar to those of the Vulcan XC-72, smaller Pt particle size of the Pt/e-CNF catalyst and stronger metal-support interaction were believed to be the main reason for its higher catalytic activity.

합성가스 생산을 위한 플라즈마-덤프 개질기 개발 (Development of a Plasma-Dump Reformer for Syngas Production)

  • 임문섭;김은혁;전영남
    • 한국수소및신에너지학회논문집
    • /
    • 제25권6호
    • /
    • pp.586-593
    • /
    • 2014
  • Limited sources of fossil fuels and also global climate changes caused by $CO_2$ emissions are currently discussed around the world. As a renewable, carbon neutral and widely available energy source, biogas is regarded as a promising alternative to fossil fuels. In this study, a plasma dump reformer was proposed to produce $H_2$-rich synthesis gas by a model biogas. The three-phase gliding arc plasma and dump combustor were combined. Screening studies were carried out with the parameter of a dump injector flow rate, water feeding flow rate, air ratio, biogas component ratio and input power. As the results, methane conversion rate, carbon dioxide conversion rate, hydrogen selectivity, carbon monoxide yield at the optimum conditions were achieved to 98%, 69%, 42%, 24.7%, respectively.

Fast and Soft Functionalization of Carbon Nanotube with -SO3H, -COOH, -OH Groups for Catalytic Hydrolysis of Cellulose to Glucose

  • Lusha, Qin;Lee, Sungho;Li, Oi Lun
    • 한국표면공학회지
    • /
    • 제53권3호
    • /
    • pp.87-94
    • /
    • 2020
  • Herein, sulfonated carbon nanotubes (CNT) have been prepared in dilute sulfuric acid (H2SO4) via a novel sulfonation approach based on gas-liquid interfacial plasma (GLIP) at room temperature. The sulfonic acid groups and total acid groups densities of CNT after GLIP treatment in 2 M H2SO4 for 45 min can reach to 0.53 mmol/g and 3.64 mmol/g, which is higher than that of sulfonated CNT prepared under 0.5 M / 1 M H2SO4. The plasma sulfonated CNT has been applied as catalysts for the conversion of microcrystalline cellulose to glucose. The effect of hydrolysis temperature and hydrolysis time on the conversion rate and product distribution have been discussed. It demonstrates that the total conversion rate of cellulose increasing with hydrolysis temperature and hydrolysis time. Furthermore, the GLIP sulfonated CNT prepared in 2 M H2SO4 for 45 min has shown high catalytic stability of 85.73 % after three cycle use.

Rate Capability of Electric Double-Layer Capacitor (EDLC) Electrodes According to Pore Length in Spherical Porous Carbons

  • Ka, Bok-H.;Yoon, Song-Hun;Oh, Seung-M.
    • 전기화학회지
    • /
    • 제10권4호
    • /
    • pp.252-256
    • /
    • 2007
  • A series of spherical porous carbons were prepared via resorcinol-formaldehyde (RF) sol-gel polymerization in the presence of cationic surfactant (CTAB, cetyltrimethylammonium bromide), wherein the carbon sphere size was controlled by varying the CTAB introduction time after a pre-determined period of addition reaction (termed as "pre-curing"). The sphere size gradually decreases with an increase in the pre-curing time within the range of 30-150 nm. The carbons possess two types of pores; one inside carbon spheres (intra-particle pores) and the other at the interstitial sites made by carbon spheres (inter-particle pores). Of the two, the surface exposed on the former was dominant to determine the electric double-layer capacitor (EDLC) performance of porous carbons. As the intra-particle pores were generated inside RF gel spheres by gasification, the pore diameter was similar for all these carbons, thereby the pore length turned out to be a decisive factor controlling the EDLC performance. The charge-discharge voltage profiles and complex capacitance analysis consistently illustrate that the smaller-sized RF carbons deliver a better rate capability, which must be the direct result of facilitated ion penetration into shorter pores.