All,

 

I think moisture (or water content) is a bigger problem for n-BuLi not just the oxygen content as it catches spontaneous fire when came in contact with air or moisture (C₄H₉Li + H₂O =E2=86' C₄H₁₀ + LiOH) and releases highly flammable gas, butane. Butane further react in presence of oxygen to form carbon dioxide and water.

 

As per the MSDS sheet, LEL for n-BuLi is not available. I also tried to find but no luck.

 

Again that does not answer your initial question.

 

 

 

 

 

 

All

 

Thank you for the initial response; you have confirmed what I noted- the data do not seem to be available.

 

Allow me to change the question-

Some facts:

The specification for oxygen in cylinder nitrogen is less than 200 ppmv and it goes down as the quality of the nitrogen goes up.  Semiconductor grade is < 3 ppmv.

 

If you were monitoring the oxygen concentration inside a glove box (containment) using nitrogen as the purge gas, what would be the oxygen concentration at which you would say (IN YOUR WRITTEN SOP) that work with a pyrophor can begin.

 

It would be really helpful to have this answer documented with data; ideally peer-reviewed, but hard anecdotal - not just opinion - would be ok.

 

And, I really do not care about t-BuLi, but used it as an example.  Again, I am trying to find support for  pyrophor use which is analogous to hydrogen, where the data clearly support <5% being not ignitable no matter the hydrogen concentration.

 

Thank you for continuing this discussion

 

Neal

 

 

Neal, are you speaking the common 1.5% to 1.7% solution in pentane?    The LEL of pentane is 1.5% (10% LEL, 1,500 ppm) which doesn't really answer your question about t-BuLi itself.  Like you I have searched and the best I could fine was how to isolate t-BuLi solutions to pure crystalline form, but it was never exposed to varying % of oxygen, all was done under argon and/or nitrogen.

 

Mel

 

 

Does anyone have any citations for the low limiting oxygen concentration of pyrophoric compounds.  I am specifically looking for the oxygen percentage at which compounds such as t-BuLi become non-ignitable.  For example, that value is 5% for hydrogen.  I have found a reference for silane, but, as is typical for silane, there are a myriad of confounding issues.

 

I have searched both SciFinder and Science Direct and have not found helpful data.

 

Thanks

 

Neal

 

 

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