Notices
Results 1 to 7 of 7

Thread: Cl

  1. #1 Cl 
    New Member
    Join Date
    Feb 2014
    Posts
    4
    Hello everybody,

    I am interested in "F gases" such as chlorofluorocarbons.
    Now, I'm not a scientist and have a limited understanding of molecular interactions so excuse anything that does not make sense.

    What I am interested in is a paragraph in a recent Green Peace publication -

    "The Scientific Assessment Panel to the Montreal Protocol recently
    raised its concerns about HFOs. These included the possibility of its
    break down products being high GWP HFCs or even ozone depleting
    substances, and the potential for low-level ozone pollution formation.23
    All this shows that the fluorocarbon industry is using the low GWP
    of these new chemicals as a front, glossing over other serious
    environmental and health issues."

    The reference in this paragraph is this - Newman et al. (2009) “HCFCs and HFCs: An Update from the
    Scientific Assessment Panel

    Now I can't find this publication anywhere. I've spent the last hour looking for it.

    My friend has told me that he thinks most F gases will deplete Ozone - I imagine they all deplete ozone since it is to do with the production of Free radicals which they should all do - But I am having immense difficulty finding any credible source that agrees with this.

    Basically, I was wondering if anybody can give me a bit more information as to the ozone depleting potential of F gases and whether anybody knows any credible sources that suggest a potential depleting effect of HFOs.

    Thanks a lot,
    I hope that made sense,
    Edd

    EDIT: Damn, I forgot to finish the title!!!


    Reply With Quote  
     

  2.  

    Related Discussions:

     

  3. #2  
    exchemist
    Join Date
    May 2013
    Location
    London
    Posts
    3,331
    Quote Originally Posted by Eddyerb View Post
    Hello everybody,

    I am interested in "F gases" such as chlorofluorocarbons.
    Now, I'm not a scientist and have a limited understanding of molecular interactions so excuse anything that does not make sense.

    What I am interested in is a paragraph in a recent Green Peace publication -

    "The Scientific Assessment Panel to the Montreal Protocol recently
    raised its concerns about HFOs. These included the possibility of its
    break down products being high GWP HFCs or even ozone depleting
    substances, and the potential for low-level ozone pollution formation.23
    All this shows that the fluorocarbon industry is using the low GWP
    of these new chemicals as a front, glossing over other serious
    environmental and health issues."

    The reference in this paragraph is this - Newman et al. (2009) “HCFCs and HFCs: An Update from the
    Scientific Assessment Panel

    Now I can't find this publication anywhere. I've spent the last hour looking for it.

    My friend has told me that he thinks most F gases will deplete Ozone - I imagine they all deplete ozone since it is to do with the production of Free radicals which they should all do - But I am having immense difficulty finding any credible source that agrees with this.

    Basically, I was wondering if anybody can give me a bit more information as to the ozone depleting potential of F gases and whether anybody knows any credible sources that suggest a potential depleting effect of HFOs.

    Thanks a lot,
    I hope that made sense,
    Edd

    EDIT: Damn, I forgot to finish the title!!!
    My feeling is this is quite a specialised and fast-moving area. I was until five years ago involved in the design of refrigerator lubricants, for which compatibility with the refrigerant fluid is crucial, and I had not heard of HFOs. I had to look them up (hydrofluoroolefins, apparently - interesting).

    I suspect your best avenue will be to contact the suppliers, for those that are still in production and especially for the HFOs as they are the new thing. For the older types e.g. CFCs, HCFCs, they will be out of production, at least in the industrialised world, due to the requirements of the Kyoto and Montreal Protocols. Of course, you may find the suppliers hype the new ones a bit, but I do not believe they will lie about the data - corporate reputation is important to them - so if you probe you should get the truth.


    Reply With Quote  
     

  4. #3  
    Forum Sophomore
    Join Date
    Jan 2014
    Posts
    106
    I'm not really experienced in this area, but I did have a look at

    Wen_Tien Tsai: Environmental risks of new-generation fluorocarbons in replacement of potential greenhouse gases
    Int. J. Global Warming, Vol 5, No. 1, 2013

    I can't see any mention of stratospheric ozone depletion in the bulk of the paper. In fact he notes that one objective of introduction of such compounds is to avoid such depletion. There is more mention of ozone creation in the troposphere. The values of a POCP for a couple of HFOs was around 5 or 6.

    You can see a summary of this work in lots of places.
    Last edited by Warron; February 6th, 2014 at 03:57 AM.
    Reply With Quote  
     

  5. #4  
    Forum Professor
    Join Date
    Jan 2013
    Posts
    1,771
    Why not return to use of AMMONIA as a refrigerant, taking reasonable precautions regarding safety (leaks, etc.), and get the hell away from synthetics altogether? Ammonia is an animal-inclusive compound. The concerns for the "ozone hole" are debateable.
    Reply With Quote  
     

  6. #5  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,168
    Quote Originally Posted by jocular View Post
    The concerns for the "ozone hole" are debateable.
    In the same sense that a 4.5 billion year old solar system is debatable. Yes?
    Reply With Quote  
     

  7. #6  
    exchemist
    Join Date
    May 2013
    Location
    London
    Posts
    3,331
    Quote Originally Posted by jocular View Post
    Why not return to use of AMMONIA as a refrigerant, taking reasonable precautions regarding safety (leaks, etc.), and get the hell away from synthetics altogether? Ammonia is an animal-inclusive compound. The concerns for the "ozone hole" are debateable.
    Ammonia is certainly still a good choice for large industrial and marine systems and will probably remain so. But it has snags for small applications such as domestic fridges and aircon units.
    Reply With Quote  
     

  8. #7  
    Forum Professor
    Join Date
    Jan 2013
    Posts
    1,771
    Quote Originally Posted by John Galt View Post
    Quote Originally Posted by jocular View Post
    The concerns for the "ozone hole" are debateable.
    In the same sense that a 4.5 billion year old solar system is debatable. Yes?
    Concerns based on widespread use of ammonia. Sorry. joc
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •