Klute
International Hazard
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Registered: 18-10-2006
Location: France
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Peracetic acid formation
SWIK has been trying to calculate peracid formation according to amount of GAA and H2O2 introduced... Thanks to a very helpfull person, he got access
to an interesting document were performic and peracetic formation, with 90%H2O2 and 30% H2O2, have been detailed by a graph... In experimental exemple
with 30% H2O2, maximum peracetic concentration is said to be 8.6% in 80 to 90h...
But the problem here is that they use excess H2O2 to drive equilibrium to the right, and SWIM would prefer using excess GAA, so SWIM can't simply
adapte molar ratios... He tried calculating maximum peracid formation with excess GAA from constant of formation determined from the document, but
found negative results :S Never been very good at maths...
He could just adapt Chromic's procedure for regular peracetic epoxidation (BTW, I guess it's been discussed before at the Hive or elsewhere, but
isn't 15% optimistic? I had the impression from different reading that 30% H2O2 would give 9% peracid AT MOST?), but he doesn't like just applicating
a "receipe", and would like to get the numbers straight for his use... So if anyone could explain the maths to calculated that, it would be very much
appreciated... alot of usefull info has been lost from precious forums.... and SWIM is either to stupid or too tired to sort it out! 
Another questions regarding peracetic: H2O is detrimental for peracid formation, so using 75% AcOH and 35% H2O2 would surely give a final
concentration inferior to 8.6 even with using a healthy excess of AcOH... But what if more than 1% H2SO4 is used to catalyse, hence neutralising some
water, and then partialy neutralized by AcONa before substrat is introduced, forming more acid and salts (which would bound some water too)? Would
this compensate a little?
And swim supposes that even if peracid concentration is inferior, using more (dilute) acid and more H2O2 would eventfully form a number of moles of
peracid suitable for oxidising the substrate, though the solution would be less reactive, implicating longer reaction times... no?
Please help SWIM out on this, he's tourmenting his brains cells...
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12AX7
Post Harlot
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What is "SWIM"? "Swim" is a verb, yet you use it as a noun. This is so screwed up.
Tim
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Klute
International Hazard
Posts: 1378
Registered: 18-10-2006
Location: France
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ha ha
I'm a deluted shizofrenic that's why
Thanks for the help mate very revelant
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