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Development of the technology for detoxification of Freons by using oxidative and reductive methods

Research Project

Project/Area Number 03555171
Research Category

Grant-in-Aid for Developmental Scientific Research (B)

Allocation TypeSingle-year Grants
Research Field 工業物理化学・複合材料
Research InstitutionKyoto Institute of Technology

Principal Investigator

IMAMURA Seiichiro  Kyoto Institute of Technology, Fac. Eng. Design, Professor, 工芸学部, 教授 (00027898)

Co-Investigator(Kenkyū-buntansha) JINDAI Hitoshi  Nippon Fine Fas Co., Manager, 工場次長
TERAMOTO Masaaki  Kyoto Institute of Technology, Fac. Eng. Design, Professor, 工芸学部, 教授 (60026086)
OKU Akira  Kyoto Institute of Technology, Fac. Eng. Design, Professor, 工芸学部, 教授 (50027885)
Project Period (FY) 1991 – 1992
Project Status Completed (Fiscal Year 1992)
Budget Amount *help
¥6,900,000 (Direct Cost: ¥6,900,000)
Fiscal Year 1992: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1991: ¥5,200,000 (Direct Cost: ¥5,200,000)
KeywordsFreon / Decomposition / Oxidation / Reduction / Acid catalyst / Durability / Naphthylide / 酸分解 / ジルコニア / リン酸 / フロン12 / 超強酸 / 還元的処理 / 脱フッ素反応
Research Abstract

Catalytic decomposition of Freon 12 (a model compound) on PO_4/ZrO_2 was carried out. Superacid PO_4/ZrO_2 whose Hammett acidity coefficient was lower than -12.14 was prepared by precipitation from zirconium (IV) oxynitrate followed by impregnation of PO_4 anion. Freon 12 was completely decomposed on this catalyst at a temperature as low as 300 ゚C. Although this catalyst was comparatively robust against inorganic fluorine produced during the reaction, it deactivated during prolonged use. In order to prolong the lifetime of this catalyst, water (1%, 4%) was added in the reaction mixture. Water helped maintain the activity of PO_4/ZrO_2, and more than 60% of Freon 12 was decomposed even after 30 h; inorganic fluorine accumulated on the surface of the catalyst was removed by hydrogen from water as HF. This result suggested the possibility of developing practical catalytic decomposition process for Freons.
Reductive method employed sodium and lithium dihydronaphthylides as reducing agents and Freon 113 as a model compound for Freons. Halogen atoms were effectively removed as sodium chloride and fluoride. The rate of defluorination was accelerated remarkably under UV irradiation, thus the defluorination was completed at a room temperature within 100 min. Analysis of the reaction intermediates suggested that the major intermediates were produced by the coupling between dihydronaphthylide and two-carbon unit of Freon 113. As the reducing ability of lithium is lower than that of sodium, ratio of dechlorination to defluorination increased by using lithium. This ratio was also increased by using diethyl ether as a solvent. These results suggested the possibility of transforming used Freons to useful fluorinated compounds.

Report

(3 results)
  • 1992 Annual Research Report   Final Research Report Summary
  • 1991 Annual Research Report
  • Research Products

    (14 results)

All Other

All Publications (14 results)

  • [Publications] S.IMAMURA: "Decomposition of dichlorodifluoromethane on BPO_4 catalyst" Ind.Eng.Chem.Res.30. 2355-2358 (1991)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1992 Final Research Report Summary
  • [Publications] S.IMAMURA: "Catalytic decomposition of halogenated organic compounds and deactivation of the catalysts" Catalysis Today. 11. 547-567 (1992)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1992 Final Research Report Summary
  • [Publications] 奥 彬: "クロロフルオロカーボン(CFC-113)の還元的脱フッ素反応における中間生成物ならびに紫外線照射効果" 日本化学会誌. 910-911 (1991)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1992 Final Research Report Summary
  • [Publications] Seiichiro Imamura: "Decomposition of dichlorodifluoromethane on BPO_4 catalyst" Ind. Eng. Chem. Res.30. 2355-2358 (1991)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1992 Final Research Report Summary
  • [Publications] Seiichiro Imamura: "Catalytic decomposition of halogenated organic compounds and deactivation of the catalysts" Catalysis Today. 11. 547-567 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1992 Final Research Report Summary
  • [Publications] Akira Oku: "Intermediates in the reductive defluorination of chlorofluorocarbon (CFC-113) and the effect of UV-irradiation" Nippon Kagaku Kaishi. 910-911 (1991)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1992 Final Research Report Summary
  • [Publications] S.Imamura: "Decomposition of dichlorodifluoromethane on BPO_4 catalyst" Ind.Eng.Chem.Res.30. 2355-2358 (1991)

    • Related Report
      1992 Annual Research Report
  • [Publications] S.Imamura: "Catalytic decomposition of halogenated organic compounds and deactivation of the catalysts" Catalysis Today. 11. 547-567 (1992)

    • Related Report
      1992 Annual Research Report
  • [Publications] 奥 彬: "クロロフルオロカーボン(CFC-113)の還元的脱フッ素反応における中間生成物ならびに紫外線照射効果" 日本化学会誌. 910-911 (1991)

    • Related Report
      1992 Annual Research Report
  • [Publications] 今村 成一郎: "フロン12の接触分解-耐フッ素性触媒についての検討" 日本化学会誌. 645-647 (1991)

    • Related Report
      1991 Annual Research Report
  • [Publications] 今村 成一郎: "Decomposition of dichlorodifluoromethane on BPO_4 catalyst" Industrial and Engineering Chemistry Research. 30. 2355-2358 (1991)

    • Related Report
      1991 Annual Research Report
  • [Publications] 奥 彬: "還元剤によるフロンの分解処理" 化学工業. 42. 451-455 (1991)

    • Related Report
      1991 Annual Research Report
  • [Publications] 奥 彬: "クロロフルオロカ-ボン(CFC-113)の還元的脱フッ素反応における中間生成物ならびに紫外線照射効果" 日本化学会誌. 910-912 (1991)

    • Related Report
      1991 Annual Research Report
  • [Publications] 今村 成一郎: "Catalysis Today vol11-Catalyst Deactivation" Elsevier, 21 (1992)

    • Related Report
      1991 Annual Research Report

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Published: 1991-04-01   Modified: 2016-04-21  

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