• 제목/요약/키워드: Co-pyrolysis

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A Volatile Organic Compound Sensor Using Porous Co3O4 Spheres

  • Kim, Tae-Hyung;Yoon, Ji-Wook;Lee, Jong-Heun
    • 한국세라믹학회지
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    • 제53권2호
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    • pp.134-138
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    • 2016
  • Porous $Co_3O_4$ spheres with bimodal pore distribution (size: 2-3 nm and ~ 30 nm) were prepared by ultrasonic spray pyrolysis of aqueous droplets containing Co-acetate and polyethylene glycol (PEG), while dense $Co_3O_4$ secondary particles with monomodal pore distribution (size: 2-3 nm) were prepared from the spray solution without PEG. The formation of mesopores (~ 30 nm) was attributed to the decomposition of PEG. The responses of a porous $Co_3O_4$ sensor to various indoor air pollutants such as 5 ppm $C_2H_5OH$, xylene, toluene, benzene, and HCHO at $200^{\circ}C$ were found to be significantly higher than those of a commercial sensor using $Co_3O_4$ and dense $Co_3O_4$ secondary particles. Enhanced gas response of porous $Co_3O_4$ sensor was attributed to high surface area and the effective diffusion of analyte gas through mesopores (~ 30 nm). Highly sensitive porous $Co_3O_4$ sensor can be used to monitor various indoor air pollutants.

저급탄의 열분해 및 촤-$CO_2$ 가스화 반응의 속도론적 연구 (Kinetic Studies of Pyrolysis and Char-$CO_2$ Gasification on Low Rank Coals)

  • 강석환;류재홍;박수남;변용수;서석정;윤용승;이진욱;김용전;김주회;박삼룡
    • Korean Chemical Engineering Research
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    • 제49권1호
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    • pp.114-119
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    • 2011
  • 인도네시아 아역청탄인 ABK탄과 중국 갈탄(lignite)과 같은 저급탄에 대한 열분해와 촤-$CO_2$ 가스화반응에 대한 실험을 비등온의 승온 조건에서 열중량분석기(Thermogravimetric analysis, TGA)를 이용하여 수행하였다. 열분해 속도는 2단계, 1차의 열분해 모델(Kissinger 법의 변형)에 의해 잘 모사되었다. 촤의 $CO_2$ 가스화반응은 수축 핵 모델에 적용하여 초기의 활성화 에너지가 ABK탄은 189.1 kJ/mol, lignite는 260.5 kJ/mol의 값을 얻었으며, 수축 핵 모델에 의해 잘 모사되었다. 특히, 촤의 $CO_2$ 가스화반응에서 활성화 에너지는 무연탄의 결과와 유사하였으며, 다른 모델이나 석탄의 종류에 따라 큰 차이를 보였다.

초음파 분무열분해를 이용한 $SrZr_{0.95}$$Y_{0.05}$$O_{2.975}$ 분말의 합성 (Synthesis of $SrZr_{0.95}$$Y_{0.05}$$O_{2.975}$ Powder by Ultrasonic Spray Pyrolysis)

  • 박양수;심수만
    • 한국세라믹학회지
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    • 제35권11호
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    • pp.1171-1181
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    • 1998
  • $SrZr_{0.95}$$Y_{0.05}$$O_{2.975}$ powder was synthesized by ultrasonic spray pyrolysis using a solution that Sr carbonate and Zr and Y nitrates were dissolved in a citric acid solution. The processes of particle formation were in-vestigated with respect to solution properties and pyrolysis temperature. With changing the solution con-centration form 0.1M to 0.01M there was a tendency that average sizes of droplets and particles were de-creased and their size distributions were narrowed. Citrate functional groups converted the droplets into gel particles which prevented an inhomogeneous precipitation of the metal ions and facilitated the diffusion of gases during thermal decomposition. As a result the powder having spherical particles without hollow par-ticles could be prepared. Low pyrolysis temperature led to amorphous particles due to incomplete pyrolysis and made the particles difficult to maintain spherical shape due to retarded gelation of the droplets. Whereas higher pyrolysis temperature produced hollow and broken particles because the droplets un-derwent rapid gelationand decomposition. The particles obtained at two pyrolysis temperature $500^{\circ}$and $1000^{\circ}C$ consisted of a perovskite phase and a very small amount of $SrCO_3$ However after calcination at $1000^{\circ}C$ the particles contained a single perovskite phase having an average particle size of 0.63${\mu}{\textrm}{m}$ and an apparent density near to the theoretical density.

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천연가스와 바이오매스로부터 개선된 DME 공정의 개발 (Development of Innovation DME Process from Natural Gas and Biomass in KOREA)

  • 조원준;송택용;백영순;김승수
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 추계학술대회 초록집
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    • pp.107-107
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    • 2010
  • Hydrogen is an alternative fuel for the future energy which can reduce pollutants and greenhouse gases. Synthesis gas have played an important role of synthesizing the valuable chemical compound, for example methanol, DME and GTL chemicals. Renewable biomass feedstocks can be potentially used for fuels and chemical production. Current thermal processing techniques such as fast pyrolysis, slow pyrolysis, and gasification tend to generate products with a large slate of compounds. Lignocellulose feedstocks such as forest residues are promising for the production of bio-oil and synthesis gas. Pyrolysis and gasification was investigated using thermogravimetric analyzer (TGA) and bubbling fluidized bed gasification reactor to utilize forest woody biomass. Most of the materials decomposed between $320^{\circ}C$ and $380^{\circ}C$ at heating rates of $5{\sim}20^{\circ}C/min$ in thermogravimetric analysis. Bubbling fluidized bed reactor were use to study gasification characteristics, and the effects of reaction temperature, residence time and feedstocks on gas yields and selectivities were investigated. With increasing temperature from $750^{\circ}C$ to $850^{\circ}C$, the yield of char decreased, whereas the yield of gas increased. The gaseous products consisted of mostly CO, CO2, H2 and a small fraction of C1-C4 hydrocarbons.

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Chemical Compositions and Pyrolysis Characteristics of Oil Shales Distributed in Korea

  • Yang, Moon Yul;Yang, Myoung Kee;Lee, Sang Hak;Wakita, Hisanobu
    • 분석과학
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    • 제8권4호
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    • pp.487-492
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    • 1995
  • The chemical compositions and pyrolysis characteristics of oil shales and source rocks distributed in the southwestern and southeastern parts of the Korean peninsular have been investigated. In order to compare the results of Korean samples with those of shales giving high oil yields, two Colorado oil shale samples and one Paris source rock samples were also investigated. Chemical compositions of the samples were analysed by means of gravimetry, CHN analysis, X-ray diffraction method, inductively coupled plasma atomic emission spectrometry and atomic absorption spectrometry. A custom made pyrolyser and a Rock-Eval system were used for the pyrolysis studies. Pyrolyses of the samples were carried out by means of a temperature controlling device to $600^{\circ}C$ at a heating rate of $5^{\circ}C/min$ with a helium flow rate of $1200m{\ell}/min$. The results of pyrolysis study indicated that Colorado shale samples belong to type I and all the other samples belong to type II.

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Pyrocarbon Whisker Growth on the Catalytic Mullite Substrate by the Pyrolysis of Methane

  • Rhee, Bosung;Park, Young-Tae
    • Carbon letters
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    • 제6권2호
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    • pp.101-105
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    • 2005
  • Like bamboo-sprouts after rains, numerous sub${\mu}m$-sized pyrocarbon whiskers growth on the Mullite ($3Al_2O_3{\cdot}2H_2O$) substrate could be observed through a looking glass during methane pyrolysis at the temperature of $1050^{\circ}C$ in this study. If the surface of substrate would be scrubbed strongly with iron metals, then finely sticked iron particles were more effective catalytic for nm-sized whisker growth. Numerous fine flakes of pyrolytic carbon were hanging by invisible nm-whiskers as like as small spiders hanging by a spiderweb. This is the identification of nm-sized whisker growth. Therefore if the pyrolysis would be stopped at the initial stage of the whisker growth, the primary lengthening growth was nm-sized whisker. So could we vary arbitrarily sizes of whisker from nm- to ${\mu}m$-sizes. But ${\mu}m$- and nm-whiskers grown with the different growth mechanism; the former was straight and the latter has twigs, The lengthening growth of whisker was depended on the flow pattern pyrolysis species on the active sites of substrate and on the growth duration. We could obtained straight whisker length of 10~20 ${\mu}m$/min during the primary growth and laboratory spiral whisker of 30~40 ${\mu}m$-diameter/hr during the secondary growth.

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천연가스 열분해에 의한 수소 및 카본 생산 (Hydrogen and Carbon Black Production by Pyrolysis of Natural Gas)

  • 윤영호;박노석;이종대;장원철;이병권;안병성
    • 한국수소및신에너지학회논문집
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    • 제14권2호
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    • pp.105-113
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    • 2003
  • The pyrolysis for production of hydrogen and high quality carbon black from natural gas were studied. The reactivities in tubular reactor and FVR(free volume reactor) for the methane pyrolysis were compared, in order to prevent the formation of undesirable carbon product such as pyrocarbon, the FVR was designed. The hydrogen yield and the formation of carbon black from methane pyrolysis in this reactor were investigated at temperature range between 1443 and 1576K. From the result of TEM (transmission electron microscopy) analysis, it was confirmed that the CFC(catalytic filamentous carbon) was formed without pyrocarbon.

폐플라스틱의 열분해 유화기술 개발 (Process Development of Pyrolysis Liquefaction for Waste Plastics)

  • 노남선;신대현;박소원;이경환;김광호;전상구;조봉규
    • 신재생에너지
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    • 제2권2호
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    • pp.118-125
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    • 2006
  • The target of this work was the process development of demonstration plant to produce the high quality alternative fuel oil by the pyrolysis of mixed plastic waste. In the first step of research, the bench-scale units of 70 t/y and the pilot plant of 360 t/y had been developed. Main research contents in this step were the process performance test of pilot plant of 360 ton/year and the development of demonstration plant of 3,000 t/y, which was constructed at Korea R & D Company in Kimjae City. The process performance of pilot plant of 360 t/y showed about 80% yield of liquid product, which was obtained by both light gas oil(LGO) and heavy gas oil(HGO), The boiling point range distribution of LO product that was mainly consisting of olefin components in PONA group appeared at between that of commercial gasoline and kerosene. On the other hand, HO product was mainly paraffin and olefin components and also appeared at upper temperature distribution range than commercial diesel. Gas product showed a high fraction of $C_3\;and\;C_4$ product like LPG composition, but also a high fraction of $CO_2$ and CO by probably a little leak of process.

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ZnO를 첨가한 PVC와 PS 혼합물의 열분해 특성에 관한 연구 (A Study on the Co-pyrolysis Characteristics of PVC and PS Mixtures with ZnO)

  • 오세천;정명욱;김희택;이해평
    • 공업화학
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    • 제16권4호
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    • pp.513-518
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    • 2005
  • 혼합비율 및 반응온도의 변화에 따른 ZnO가 첨가된 PVC와 PS의 혼합 열분해 특성에 관한 연구를 TG와 GC-MS를 이용하여 수행하였다. 본 연구로부터 혼합물에 있어서 PS의 양이 증가할수록 액상 생성물은 증가하였으며 기상 생성물은 감소함을 알 수 있었다. 또한 ZnO의 첨가량이 증가할수록 기상 생성물과 염화수소의 발생량은 감소하였으며 염화수소의 발생 억제 및 액상 생성물의 최대수율을 얻기 위한 최적의 반응온도는 $500^{\circ}C$임을 알 수 있었다.

폐플라스틱의 열분해 유화기술 개발 (Process Development of Pyrolysis Liquefaction for Waste Plastics)

  • 노남선;신대현;박소원;이경환;김광호;전상구;조봉규
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2006년도 춘계학술대회
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    • pp.523-526
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    • 2006
  • The target of this work was the process development of demonstration plant to produce the high quailty alternative fuel oil by the pyrolysis of mixed plastic waste. In the first step of research, the bench-scale units of 70t/y and the pi lot plant of 360 t/v had been developed. Main research contents in this step were the process performance test of pilot plant ot 360ton/year and the development of demonstration plant of 3 000 t/y which was constructed at Korea R & D Company in Kimjae City. The process performance of pilot plant of 360 t/v showed components in PONA group appeared at between that of commercial gasoline and kerosene. On the other hand, HO product was mainly paraffin and olefin components and also appeared at upper temperature distribution range than commercial diesel. Gas product showed a high fraction of $C_3\;and\;C_4$ product like LPG composition, but also a high fraction of $CO_2$ and CO by probably a little leak of process.

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