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maxidastier
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It's like a curse. I cannot get any Napthalene in Germany! Can you?
What about urea to nitrate to ureanitrate?
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Rosco Bodine
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You have to lose the sulfuric acid first on that one, precipitated as gypsum, by
a partial neutralization with lime, and then filter and neutralize the residual nitric acid with the urea and evaporate the solution to crystallize
the UN, but there would be no acid recovery whatever as reusable acid going that route.
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maxidastier
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| Quote: |
but there would be no acid recovery whatever as reusable acid going that route. |
You mean, I don't have recovered acid at the end?
I wouldn't care about that if at least there was some use for it...
However, I don't know if there are other materials that could be nitrated in that waste acid mix.
Maybe there's something that strips off some more nitrogen to enhance the efficiency? (Apart from toluene, starch/cellulose and Napthalene)
[Edited on 19-2-2011 by maxidastier]
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mabuse_
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One more question:
The nitration process itself is exothermic.
To my knowledge the only other exothermic reaction whould be carbonisation of the erythritol.
Temperature during my last experiment did not exceed 25°C, so I guess that no significant carbonisation ocurred.
Can i deduce that my nitration isn't finished from the fact that the slurry still generates heat?
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quicksilver
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Not entirely. The measurement of heat would need be taken over a protracted period of time and with that time, contact of the mixed acid would
complicate the results. Remember that the solution is now at a much greater density & w/ that density comes a slower level of cooling.
However; the generalist picture is the "heat produces inefficiency" in esters. It's also a warning sign. Working toward a colder synthesis is
generally safer and more productive with esters. A "cap" of 25 C is (IMO) a higher end of safety and efficiency. Effective stirring, command of lower
temps and efficient contact is often the ideal. I believe that the question is very logical but complicated by conditions in nitric ester synthesis.
Different solid nitrates to produce a HNO3 have ranges of productivity. Leaving that aside, the use of that technique demands a complete solution of
the nitrate within the H2SC4 and a lowering and maintenance [of a low temperature] ( along with "stir-contact") to be as effective a synthesis as
possible. Yield weight & crystal format [from re-crystallization] is a useful indicator.
Precursor addition speed & weight can control a great deal of the esterifaction. Do not attempt to recover acids; it's never worth the risk.
Enormous research have been attempted toward that end; many tragedies resulted in certain conclusions. Benzene-ring nitration's are not nitric esters.
Please note that the above is opinion based on observation & selections in Federoff.
[Edited on 22-5-2011 by quicksilver]
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mabuse_
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Thanks for your answer.
I know it was pretty warm, but i wanted to speed it up a little.
Yield was about 65g from 50g Erythritol (after recrystallisation, so not very meaningful).
Problem is that my improvised magnetic stirrer will not handle such viscous stuff and hand stirring for an hour or longer is rather exhausting 
When I discontinued stirring for some time, resuming whould cause a significant temperature jump, about 2-4°C, and noticeable gas emission.
Perfect stirring would be an tremendous improvement.
I'm planning to get a proper magnetic stirrer, but i guess even these machines won't handle this task.
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quicksilver
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There are some cute "tricks" to using a magnetic stirring device with thick material.
Starting and stopping (the stirring process) may result in oxidation of the precursor via heat, etc - in a greater % than expected. That and temp in
general is one of the most important things about utilizing one (AND having a good selection of stir-bars). There are many designs for stirring
devices.
Some member have made them for very little money and the result were supposedly fantastic.
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