• 제목/요약/키워드: Microwave synthesis

검색결과 235건 처리시간 0.02초

카올린으로부터 마이크로파 에너지를 이용한 무기고분자인 수화 황산 알루미늄의 합성 (The Synthesis of Hydrated Aluminum Sulfate from Kaolin Using Microwave Energy)

  • 박성수;황은희;박희찬
    • 공업화학
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    • 제9권4호
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    • pp.481-485
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    • 1998
  • 마이크로파 열원을 이용하여 황산 용액에서 카올린을 가열 반응시켜 무기고분자인 수화 황산 알루미늄을 합성하였다. 하소된 카올린으로부터 알루미나의 최대 추출율은 재래식 열공정 ($80^{\circ}C$, 1 M 및 240분)에서 72.8%이었고, 마이크로파 공정 ($90^{\circ}C$, 1 M 및 60분)에서 99.9%이었다. 재래식 열공정에서와는 달리 마이크로파 공정에서 추출 합성된 수화 황산 알루미늄 시료는 빠른 결정립 성장에 의해 거대 크기의 판상으로 이루어진 층상구조로 존재하였다. 마이크로파와 재래식 열공정에서 합성하여, $1100^{\circ}C$에서 하소된 시료들을 모두 구형으로 응집된 분말상의 ${\gamma}-Al_2O_3$ 존재하였고, 이 시료들의 비표면적은 각각 113.5와 $106.6m^2/g$이었고, 입자의 평균 입경은 각각 46.5와 $26.3{\mu}m$이었다.

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마이크로파에 의한 바이오디젤 합성의 가속화와 에너지 효율성 (Microwave-enhanced Acceleration and Energy-efficiency of Biodiesel Synthesis)

  • 김대호;정순신;설승권
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 추계학술대회 초록집
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    • pp.108.2-108.2
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    • 2011
  • This presentation shows energy-efficiency of microwave-accelerated esterification of free fatty acid with a heterogeneous catalyst by net microwave power measurement. In the reaction condition of 5wt% sulfated zirconia and 1:20 molar ratio of oil to methanol at $60^{\circ}C$ and atmospheric pressure, more than 90% conversion of the esterification was achieved in 20 minutes by microwave heating, while it took about 130 minutes by conventional heating. Electric energy consumption for the microwave heating in this accelerated esterification was only 67% of estimated minimum heat energy demand because of significantly reduced reaction time.

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Montmorillonite K-10 Clay as an Efficient Reusable Heterogeneous Catalyst for the Solvent-Free Microwave Mediated Synthesis of 5-Substituted 1H-Tetrazoles

  • Marvi, Omid;Alizadeh, Abdolhamid;Zarrabi, Saeid
    • Bulletin of the Korean Chemical Society
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    • 제32권11호
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    • pp.4001-4004
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    • 2011
  • Various 5-substituted 1H-tetrazole derivatives were synthesized in a simple and environmentally benign method from the reaction of aryl and benzyl nitriles with sodium azide in solvent-free media using montmorillonite K-10 clay as solid recyclable heterogeneous acidic catalyst and microwave irradiation in good yields and short reaction times.

Microwave-Assisted Solvent and Catalyst Free Synthesis of 2H-Pyrans

  • Edayadulla, Naushad;Lee, Yong Rok
    • Bulletin of the Korean Chemical Society
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    • 제34권10호
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    • pp.2963-2967
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    • 2013
  • This paper describes a simple and efficient method involving domino Knovenegal/$6{\pi}$ electrocyclization for the preparation of a variety of 2H-pyrans using microwave irradiation under solvent- and catalyst-free conditions. This method offers the advantages of a green approach, high yields, and short reaction times. Sixteen compounds (9a-p) were obtained in good to excellent yields using the procedure.