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Author: Subject: poor yields?
Antiswat
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[*] posted on 6-4-2013 at 13:47
poor yields?


i had a dream where i mixed 20 mL 96% H2SO4 with 10 mL 62% HNO3 slowly to keep the temperature under control (didnt go near 20*C)
then in my dream i added 3g erythritol very fine powder slowly and took it out of cooling
then i raised the temperature and tried to stir it abit but often missed stirring it
after longer time and it had reached 25*C it became almost transparent
i poured it in cold water and got a precipitate (400 mL used?)
then i filtered it off
scraped off filter
into beaker
added ethanol
filter off insoluble's, added to icecold water (400 mL?)
and got the final pricipitate, i got 0.62g total of dry stuff
used 3g erythritol
should i have used other ratios in my dream? i mean if i end up dreaming the same..




~25 drops = 1mL @dH2O viscocity - STP
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https://en.wikipedia.org/wiki/Solubility_table
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Simbani
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[*] posted on 6-4-2013 at 14:22


The key is to let the temperatur not go to RT, it´s better to work at 5°C. After filtering it is better to neutralise the stuff and then recrystallise,
for increased purity. If you do this, you can cool the filtered solution of ETN in EtOH down to like -20°C and filter the crystals.
These are much better to work with and very pure.
As a additional note, one should nitrate not less than 10g of E to ETN in my opinion. The loss from filtering and such is simply too high.
Your ratios are right.

My experiences with temperature: (same filtering methode and circumstances)
24g E + 85ml HNO3(53%) + 130ml H2SO4(96%) ==> 22g ETN after filtering and recrystallisation (3 hours reaction time (moderate cooling))
24g E + 85ml HNO3(53%) + 130ml H2SO4(96%) ==> 29g ETN after filtering and recrystallisation (6 hours reaction times (strong cooling))


[Edited on 6-4-2013 by Simbani]




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Antiswat
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[*] posted on 6-4-2013 at 15:38


Quote: Originally posted by Simbani  
The key is to let the temperatur not go to RT, it´s better to work at 5°C. After filtering it is better to neutralise the stuff and then recrystallise,
for increased purity. If you do this, you can cool the filtered solution of ETN in EtOH down to like -20°C and filter the crystals.
These are much better to work with and very pure.
As a additional note, one should nitrate not less than 10g of E to ETN in my opinion. The loss from filtering and such is simply too high.
Your ratios are right.

My experiences with temperature: (same filtering methode and circumstances)
24g E + 85ml HNO3(53%) + 130ml H2SO4(96%) ==> 22g ETN after filtering and recrystallisation (3 hours reaction time (moderate cooling))
24g E + 85ml HNO3(53%) + 130ml H2SO4(96%) ==> 29g ETN after filtering and recrystallisation (6 hours reaction times (strong cooling))


[Edited on 6-4-2013 by Simbani]


hm.. wow.. more than one hour?? another thing did you stir it at this time?
ive seen yield also depends on what you use where it all boils down to: KNO3 > NH4NO3 > HNO3
i like HNO3 myself as i got 10 litres [= and its not so thick, tho this might make it better
i could put it in my fridge (temp. varies from where i place it, usually something around 0*C)
my first batch i used 1.45g E and i got well around same amount as E used, but this time, in my dream i got only 0.6g
just had a little daydream where i melted it using sparklers and the etn packed in al foil, i imagined a very loud bang, to my surprise.. amazing daydream..

but very interesting with the reaction time.. never thought about letting it react longer than one hour?? ive heard also that higher reaction temperature (20-40*C) would be the best for yield..




~25 drops = 1mL @dH2O viscocity - STP
Truth is ever growing - but without context theres barely any such.

https://en.wikipedia.org/wiki/Solubility_table
http://www.trimen.pl/witek/calculators/stezenia.html
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Ral123
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[*] posted on 6-4-2013 at 23:15


Once a batch of NG was made. 65% HNO3 was used, 50ml NG were done. Then similar sized batch was done, but with NH4NO3/H2SO4 the yield was x3. HNO3 gave nice clean reaction, NH4NO3 gave high yields.
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Adas
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[*] posted on 7-4-2013 at 00:40


Strange dreams xD

The best yields are obtained when you let it react in cold, and then, when the reaction slows down too much, let it heat up to room temperature, and then to around 30°C.




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Ral123
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[*] posted on 7-4-2013 at 04:30


If etritrithol is to be mixed with nitrating mixture at low temperature, no reaction my occur. When all etritrithol is added and temperature is risen, all may react at once, causing runaway. You know ETN will explode before the H2SO4 begins to boil. I guess this would be a nightmare of some sort :)
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[*] posted on 7-4-2013 at 05:49


hm.. well yea its strange how KNO3 NH4NO3 and HNO3 affects the nitration.. i found that NH4NO3 is best for NC, and apparently KNO3 is better for ETN?
but yes there might be no reaction at low temperature, i think that would turn into a nightmare yes :P
when i took it out of cooling;; in my dream, i had thermometre in all the time and i didnt see any rising in temperature, so i actually boiled some water and put the beaker into, i forgot to stir the first long time, at the time where the temp. was at 25*C it was very clear (indicates there is some reaction) and it was quite thick
about NG, im afraid of dreaming about NG as it might turn into a nightmare without proper heat control etc.
also the fact that NG can spontaneously go off if it changes temperature too fast (i heard that from a reliable source, long time ago tho)
that wouldnt be a good dream, would it? ;P




~25 drops = 1mL @dH2O viscocity - STP
Truth is ever growing - but without context theres barely any such.

https://en.wikipedia.org/wiki/Solubility_table
http://www.trimen.pl/witek/calculators/stezenia.html
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Ral123
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[*] posted on 7-4-2013 at 06:18


ETN=NG as sensitivity, at least NG doesn't require boiling solvent to recrystalise. Also incidents with ETN seem to be more high order then with NG
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[*] posted on 7-4-2013 at 09:13


The best product come from the cleanest nitration mix. H2SO4 + a nitrate salt tends to have a noticeable amount of dissolved NO2, where as HNO3 or better yet, white fuming HNO3 makes for a crystal clear nitration mix. ETN made via nitrate salt is visually impure even after one or two recrystalizations, where ETN made with white fuming nitric is pure white after one recryst.

Best yields I've seen have the reaction start around 15c then work up to 25c or a little more. Good stirring is really important, and fine powdered clump free erythritol helps yields as well.
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Antiswat
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[*] posted on 9-4-2013 at 07:43


Quote: Originally posted by Ral123  
ETN=NG as sensitivity, at least NG doesn't require boiling solvent to recrystalise. Also incidents with ETN seem to be more high order then with NG


well considering that you need to smack it quite hard with a hammer i dont really see the problem, no offense.. (:




~25 drops = 1mL @dH2O viscocity - STP
Truth is ever growing - but without context theres barely any such.

https://en.wikipedia.org/wiki/Solubility_table
http://www.trimen.pl/witek/calculators/stezenia.html
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Antiswat
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[*] posted on 9-4-2013 at 09:34


Quote: Originally posted by CaliusOptimus  
The best product come from the cleanest nitration mix. H2SO4 + a nitrate salt tends to have a noticeable amount of dissolved NO2, where as HNO3 or better yet, white fuming HNO3 makes for a crystal clear nitration mix. ETN made via nitrate salt is visually impure even after one or two recrystalizations, where ETN made with white fuming nitric is pure white after one recryst.

Best yields I've seen have the reaction start around 15c then work up to 25c or a little more. Good stirring is really important, and fine powdered clump free erythritol helps yields as well.


true about the WFNA, but im not sure if im wanting to run a HNO3 destillation in my apartment without proper things for doing it as im unsure whether 99% HNO3 can or will etch normal plastic types, as i have only plastic adapters to my beakers and flasks, tho i have PTFE hose

edit:
also, about the stirring, i guess i would prefer a smaller diametre beaker rather than it just being a thin layer if im going to stir it, i was thinking about just letting it cool for 6 hours without much stirring as that would mean there would be a leak thus escape hope for the HNO3 thus possibly lower yield..
then the 2 last hours i would let it heat up to and + 30*C over some hours
but the stirring; i thought it was just to remove these infamous hotspots, have i got that wrong?

[Edited on 9-4-2013 by Antiswat]




~25 drops = 1mL @dH2O viscocity - STP
Truth is ever growing - but without context theres barely any such.

https://en.wikipedia.org/wiki/Solubility_table
http://www.trimen.pl/witek/calculators/stezenia.html
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