Sciencemadness Discussion Board

nitroglycerin from biodiesel

darel - 2-8-2008 at 08:52

I have just finished my biodiesel set up and realized that the waste glycerin my not need to be disposed of. Could I nitrate this glycerin as is or should I clean it? How would I clean it?

ScienceSquirrel - 2-8-2008 at 15:17

If I ever wished to make nitroglycerine then I would start from reagent grade chemicals and I would work on a gram scale at the most.
10 ml of nitroglycerine will result in a huge bang if it explodes.
Making small amounts of explosive materials with plenty of precautions from a curiosity point of view is OK.


What you are proposing is nuts!

[Edited on 2-8-2008 by ScienceSquirrel]

Ritter - 2-8-2008 at 17:00

Quote:
Originally posted by ScienceSquirrel
If I ever wished to make nitroglycerine then I would start from reagent grade chemicals and I would work on a gram scale at the most.
10 ml of nitroglycerine will result in a huge bang if it explodes.
Making small amounts of explosive materials with plenty of precautions from a curiosity point of view is OK.


What you are proposing is nuts!

[Edited on 2-8-2008 by ScienceSquirrel]


I have a friend who lost most of his left hand while making NG in his basement. Thirty years later & he was still making 20-30 ml batches...on the hood of his car in the parking lot of his apartment complex. And NG gave him the characteristic blinding headaches. Go figure...

Nitroglycerin from biodiesel

darel - 2-8-2008 at 21:03

I am not planning to use all the glycerin by product at once. I am familiar with the NG procedure and take great care in making small batches. I'am just looking for a use of what is normally thrown out.

kclo4 - 2-8-2008 at 21:13

You could probably purify it some how to make NG, but why bother when you can get 99% pure anhydrous stuff at walmart for a few bucks?
What would the impurities even be in your glycerin?
I search around a tad bit and there are actually a ton of uses for glycerin and maybe a few interesting reactions.
http://www.sciencemadness.org/talk/misc.php?action=search
Plus, if your not sealing glass joints or making formic acid out of it, you could always use it as a skin moisturizing agent or some junk like that, right? :P

not_important - 2-8-2008 at 21:32

If you're using the standard backyard wasteful biodiesel process, the glycerol is rather dirty, worse if you're using waste cooking oils. Neutralisation to near pH 7, followed by distillation under reduced pressure at least once is needed.

blogfast25 - 3-8-2008 at 04:54

And I'm a little surprised that what is a potentially seriously hazardous procedure (making NG), resulting in a very energetic material is allowed to stay up here in General Chemistry whereas a much more innocent (and IMHO also chemically more interesting) thread on dampened Mn oxide thermites was dumped rather unceremoniously in the Energetic Materials section...

ScienceSquirrel - 3-8-2008 at 06:22

The recovery of methanol and glycerine from biodiesel waste is discussed on several biodiesel sites.

Basically the process consists of;

1) Recovery of the methanol by distillation, a fair excess is used so this is quite useful on a large scale

2) Addition of sulphuric acid to precipitate potassium sulphate and fatty acids. This solid is removed by filtration.

3) Removal of the residual water under a light vacuum

4) Vacuum distillation to yield the pure glycerine