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Hydro Fluorinated Ethers as replacements for Chloro-Fluorinated Carbons

Hydro Fluorinated Ethers as replacements for Chloro-Fluorinated Carbons. Chemistry 671 15 November, 2011 Richard Madden. Flourinella. Flourinella and her evil sisters. Chlora and Broma. Apologies to Walt Disney. Fun Facts about Fluorine.

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Hydro Fluorinated Ethers as replacements for Chloro-Fluorinated Carbons

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  1. Hydro Fluorinated Ethers as replacements for Chloro-Fluorinated Carbons Chemistry 671 15 November, 2011 Richard Madden

  2. Flourinella

  3. Flourinella and her evil sisters Chlora and Broma Apologies to Walt Disney

  4. Fun Facts about Fluorine • Fluorine is in Group 17, Period 2 of the Periodic Table with an atomic number of 9 and an atomic mass of 18.998 amu.

  5. Fun Facts about Fluorine • Fluorine is in Group 17, Period 2 of the Periodic Table with an atomic number of 9 and an atomic mass of 18.998 amu. • Fluorine is the most electro-negative element (3.98 on the Pauling Scale of Electro-negativity)

  6. Fun Facts about Fluorine • Fluorine is in Group 17, Period 2 of the Periodic Table with an atomic number of 9 and an atomic mass of 18.998 amu. • Fluorine is the most electro-negative element (3.98 on the Pauling Scale of Electro-negativity) • It’s Standard State is a gas (298 K) with a boiling point of 85.03 K (-188.12˚C)

  7. Fun Facts about Fluorine • Fluorine is in Group Periodic Table with an atomic number of 9 and an atomic mass of 18.998 amu. • Fluorine is the most electro-negative element (3.98 on the Pauling Scale of Electro-negativity) • It’s Standard State is a gas (298 K) with a boiling point of 85.03 K (-188.12˚C) • It has a C-F bond enthalpy of 552 KJ/Mol.

  8. Fun Facts about Fluorine • Fluorine is in Group Periodic Table with an atomic number of 9 and an atomic mass of 18.998 amu. • Fluorine is the most electro-negative element (3.98 on the Pauling Scale of Electro-negativity) • It’s Standard State is a gas (298 K) with a boiling point of 85.03 K (-188.12˚C) • It has a C-F bond enthalpy of 552 KJ/Mol. • Fluorine has a van der Waal’s radius of 132.3 pm. (H=120 pm)

  9. A Brief History of CFC’s • Fluorine was first described in 1529. It was used in the form of Fluorspar to remove impurities during metal smelting. Derived from the Latin word Fluo, meaning “to flow”. • The electrolytic isolation of Fluorine was accomplished in 1886 by Henri Moissan in a process still used commercially today. Moissan received the Nobel Prize in Chemistry for this process in 1906. • Belgian scientist Frederick Swarts pioneered the synthesis of CFC’s in the 1890’s. The process was improved by Thomas Midgley Jr. while working for DuPont in 1928.

  10. Ozone is formed by O2 reactingwith atomic oxygen in the stratosphere (Dissociation energy of O2 bonds supplied by UV radiation)

  11. Problems of Existing Compounds Catalytic Ozone Destruction by ChlorofluoroCarbons Atomic Chlorine is an efficient X catalyst in the destruction of Ozone;

  12. Comparison of the Montreal Protocol and United States Phaseout Schedules EPA Regulations, Sections 601-607 of the Clean Air Act

  13. Hydro ChlorofluoroCarbons Hydro Chloroflouro Carbons (HCFC’s) have distinct advantages over CFC’s. Hydrogen abstraction of HCFC’s leads to much shorter Atmospheric lifetimes. Thus, these compounds are far less likely to migrate to the stratosphere.

  14. Problem Solved??? Both CFC’s and HCFC’s are potent Green House Gases. They Absorb IR radiation between 8 and 13 m.

  15. Nations to ramp up phase-out of ozone-killers 200 nations agree to speed elimination of HCFCs, major greenhouse gas TORONTO — Governments of almost 200 countries have agreed to speed the elimination of a major greenhouse gas that depletes ozone, U.N. and Canadian officials said Saturday, describing a deal they said was a significant step toward fighting global warming. The agreement reached Friday night will accelerate a treaty to freeze and phase out hydrochlorofluorocarbons (HCFCs) which are used in home appliances, some refrigerators, hair sprays and air conditioners, said Nick Nuttall, spokesman for the United Nations Environment Program. 9/23/2007

  16. Nations to ramp up phase-out of ozone-killers 200 nations agree to speed elimination of HCFCs, major greenhouse gas TORONTO — Governments of almost 200 countries have agreed to speed the elimination of a major greenhouse gas that depletes ozone, U.N. and Canadian officials said Saturday, describing a deal they said was a significant step toward fighting global warming. The agreement reached Friday night will accelerate a treaty to freeze and phase out hydrochlorofluorocarbons (HCFCs) which are used in home appliances, some refrigerators, hair sprays and air conditioners, said Nick Nuttall, spokesman for the United Nations Environment Program. 9/23/2007

  17. Hydro Fluorinated Ethers

  18. Atmospheric Oxidation of HCFC-123

  19. Despite Advantages, HFE’s are still relatively unknown. • There is growing concern about the atmospheric conversion of HFE’s into Trifluoro Acetic Acid.

  20. Compounds known to produce TFA (CF3C(O)OH) in the atmosphere. [1] Orkin and Khamagonov (1993); [2] Brown et al. (1989); [3] WMO (1989); [4] IPCC (1996).

  21. Oxidation is initiated by reaction with OH radicals giving a halogenated alkyl radical which adds O2 to give the corresponding peroxy radical (RO2). Peroxy radicals react with three important trace species in the atmosphere: NO, NO2, and HO2 radicals. Reactions with HO2 and NO2 delay, but do not prevent, the conversion of peroxy (CF3CXYO2) into alkoxy (CF3CXYO) radicals. Reactions of haloperoxy radicals with NO are rapid and give the alkoxy radical with essentially 100% yield. The atmospheric fate of the alkoxy radical, CF3CXYO, is either decomposition or reaction with O2. Decomposition occurs by C-C bond fission, or by the elimination of a Br, Cl, or CF3 group. The atmospheric fate of CF3C(O)X (X=F or Cl) is dominated by incorporation into rain-cloud-sea water followed by rapid hydrolysis to trifluoroacetic acid. Photolysis is a competing loss mechanism for CF3C(O)Cl and limits its conversion into CF3C(O)OH to 60% (Cox et al., 1995). There are no competing loss processes for CF3C(O)F; it is converted entirely into CF3C(O)OH. Although CF3C(O)OH is produced in aqueous phase chemistry, is highly soluble and partitions into the water phase (Bowden et al., 1996), the evaporation of cloud droplets can transfer CF3C(O)OH to the gas phase where it can react with OH radicals. However, this reaction is slow (Carr et al., 1994; Møgelberg et al., 1994) and is only a minor (<5%, Kanakidou et al., 1995) loss of CF3C(O)OH. The main atmospheric fate of CF3C(O)OH is rain-out to the surface.

  22. The End Thank You!

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