Sciencemadness Discussion Board

Safe Destruction of Nitroethane

nimgoldman - 6-11-2018 at 09:08

I am trying to find a safe method to destroy a small amount (10-50 mL) of nitroethane.

I usually recycle solvents, but some is always left behind (e.g. residue from distillation). Some I have (2-5 mL) is possibly contaminated with toxic dimethylnitrosamine, hence destruction is preferred over recycling.

The amount is too small to pay for professional waste disposal, yet too large to just discard it (environmental and health hazard).

One possible option is combustion but unlike with nitromethane, this produces toxic oxides of nitrogen (I have a fume hood so this is not a huge issue).

Using strong acids, strong bases and oxidizers is hazardous as nitroethane forms shock explosives with them.

Evaporation might be yet another option (e.g. soaking in a towel and leaving to evaporate to dryness in a well ventilated or outside area).

I have a feeling that a controlled combustion (e.g. in a vessel) is not such a huge issue since it is destroyed this way industrially and it is sometimes used as a fuel additive.

Tsjerk - 6-11-2018 at 09:19

I would go for combustion, whatever nitrogen oxides you emit won't hurt compaired to what is emitted on a daily base by cars.

If you really want to be good for the environment, I never do but props for you, you could consider collecting it with other waste. As long as there are no metals and halogens you can collect until you have a couple of liters.

Herr Haber - 7-11-2018 at 03:46

Combustion !

And if it didnt contain other nasties I'd use it to clean a white board that someone used a permanent marker on :)

Sulaiman - 7-11-2018 at 04:07

50ml of nitroethane is not a lethal quantity but it would cause harm if ingested,
and 50 ml nitroethane burned outdoors is unlikely to be a significant contribution to local air pollution,
so I would just burn it.

I'd probably be tempted to do something more 'interesting' such as
pouring it over a pile of potassium permanganate or some other oxidants,
just to see what happens :D

morganbw - 7-11-2018 at 06:33

I would save it and keep adding to it until there is enough to distill. That or just add it back into your next distillation of the product.

It is yours, however, to do with, as you wish.

unionised - 7-11-2018 at 12:41

Next time you have some garden waste (e.g. hedge clippings) to burn, add this to them just before lighting the fire.

nimgoldman - 7-11-2018 at 13:33

Quote: Originally posted by morganbw  
I would save it and keep adding to it until there is enough to distill. That or just add it back into your next distillation of the product.

It is yours, however, to do with, as you wish.


The amount I have is just 1-2 mL, really a minute amount.

I asked about the 10-50 mL range theoretically, to discuss possible desctruction in case I have more that I need to discard relatively safely.

I planned to collect that for purification, but I got scared of the possible nitrosamine contam - especially the dimethyl- species which I've read is extremely toxic and carcinogenic, freely soluble in water and nearly all organic solvents (what a nasty chemical that is).

Unfortunately, the methods capable of destroying nitrosamine will also destroy nitroethane.

morganbw - 7-11-2018 at 13:53

I guess I need to do some research on nitrosamine formation when making nitroethane. I had never heard of it before until the recent thread which implied it. I do not recall seeing anything backing it up except thought experiments.

At any rate, it is not in my worry box.

nimgoldman - 8-11-2018 at 08:04

Quote: Originally posted by morganbw  
I guess I need to do some research on nitrosamine formation when making nitroethane. I had never heard of it before until the recent thread which implied it. I do not recall seeing anything backing it up except thought experiments.


The theory goes that Kornblum-modified Victor Meyer reaction for producing nitroethane might create the right conditions for nitrosodimethylamine formation if impure DMF is used (dimethylamine is a comon contaminant in DMF).

But I will burn it. Better be safe than sorry (or dead).

Nitrosodimethylamine can be (like other nitroso- compounds) destroyed by potassium permanganate in sulfuric acid. Hmm... might make an interesting reaction with the nitroethane.

weilawei - 8-11-2018 at 10:51

I've used sulfuric acid to destroy anime impurities mixed into primary alcohols, specifically methylamine and dimethylamine, per the book Purification of Laboratory Chemicals. This may not be safe for your purposes as it's concentrated.

clearly_not_atara - 8-11-2018 at 11:12

NOx emissions should be very low from such a small amount. You can decrease them further by mixing with another fuel such as cellulose (as unionised suggests) or alcohol before combustion.
Quote:
anime impurities


Nani???!

weilawei - 8-11-2018 at 13:03

Quote: Originally posted by clearly_not_atara  
NOx emissions should be very low from such a small amount. You can decrease them further by mixing with another fuel such as cellulose (as unionised suggests) or alcohol before combustion.

Quote:
anime impurities


Nani???!


Quote:
Other purification procedures include pre-treatment with conc H2SO4 (3mL/L) to eliminate amines, and with KMnO4 to oxidise aldehydes, followed by refluxing with KOH to resinify aldehydes, and distilling to remove traces of H3PO4 and other acidic impurities after passage through silica gel, and drying over CaSO4. Water can be removed by azeotropic distillation with dichloromethane (azeotrope boils at 38.1o and contains 1.8% water) or 2,2,4-trimethylpentane. [Beilstein 1 IV 1289.


I have a different edition (that's quoted from 6ed.) at home, but the description is substantially the same. More importantly, it works like a charm in practice. The "impurities" were leftovers from a workup of a reaction. I clean up and recover my solvents, as I'm aiming for a zero hazardous waste output in my lab. It's not always easy, and 100% isn't really possible, but I sleep better knowing I'm not putting anything out there and my costs for normal hazardous waste disposal are minimized. Plus, I don't have to keep buying more solvents. At my work, we use solvents by the thousands of gallon and burn off or ship out hundreds of gallons a day, all with strict EPA licensing and auditing of our waste streams and emissions. I can't afford to imitate industry.

Also, the original question was about nitroethane, but I was focused on the possible impurities the OP described and the post immediately prior to mine. Perhaps my comments are not applicable to this situation.

[Edited on 8-11-2018 by weilawei]

woelen - 12-11-2018 at 04:19

1 to 2 ml of (impure) nitromethane? Not worth any hassle. Just take a paper tissue, go outside and pour the liquid on it. For added fun you can burn the tissue, otherwise just let it get dry and throw it in the waste bin afterwards.

Cleaning your glassware can be done by adding a solution of NaOH to it and shake it. The amount is so low that there will be no risk of dangerous reactions. Just let all of it dissolve in the solution of NaOH and flush it down the drain.