Sciencemadness Discussion Board

Distilled some EtOH denatured with Bitrix, and the distillate smells funny

SuperOxide - 11-1-2023 at 12:08

I use a decent amount of ethanol and typically I'll just buy a few 750mL bottles of Everclear from Walmart, dry them with sieves for a few days, then react it with some sodium to get rid of the last vestiges of water, then distill it. But that's getting a bit expensive, so I started looking for some denatured ethanol that I could... de-denature?

The product I settled on was this 200 Proof Ethanol - Denatured with Bitrix by USA Pure. The "Bitrix" they refer to is the bitterant denatonium benzoate, which unlike other bitterants, is a solid that has a relatively high melting point. So in theory, it should completely stay behind once it's been distilled.

I distilled about 2L of it today, and to my surprise, the distillate doesn't smell like pure ethanol. It smells like some bitterant (maybe slightly like tert-Butyl alcohol, but not nearly as intense or bad). I also can't find a damn SDS/MSDS sheet for it to verify that it only has the one bitterant included.

Questions: Has anyone used this brand of Ethanol before and stripped out the denatonium benzoate?
Did it have a smell left over afterwords?
Could it be possible that there are other denaturants or bittering agents in this than just Bitrix? Is there an easy way to test (other than NMR or chromotography)?

Thanks

Fulmen - 11-1-2023 at 12:28

The classic additive around here was 2% MIBK. I think it forms an azeotrope that makes it impossible to distill off, but it rarely affects performance (at least as a solvent).

SuperOxide - 11-1-2023 at 14:03

Quote: Originally posted by Fulmen  
The classic additive around here was 2% MIBK. I think it forms an azeotrope that makes it impossible to distill off, but it rarely affects performance (at least as a solvent).

Hmm... I have my doubts. When I lookup MIBK, the NIOSH page for it says it's a "Colorless liquid with a pleasant odor." While this odor isn't as bad as the EtOH I got that was denatured specifically with tert-Butyl alcohol, it's still far from a pleasant odor.

Fulmen - 11-1-2023 at 15:20

It's been a while since I've been around the stuff, I remember the smell as stronger and more distinct than EtOH. I wouldn't want to call it bad, but you really wasn't tempted to take a sip either.

Twospoons - 11-1-2023 at 20:25

As I recall the whole purpose of the denaturants is to make the alcohol undrinkable (and therefore not taxable), and they are usually chosen such that simple distillation wont work - as that is a process that is far too accessible for most people.

Deathunter88 - 12-1-2023 at 02:09

FYI you don't need to find the SDS to know that there is more than just Bitrix in the denatured alcohol because it is not legal to denature alcohol with just Bitrix. Here is a list of all formulas that can be sold as denatured alcohol in the US:

The closest I can find is Formula #40-B under Speciallty Denatured Spirits with the following additives: https://www.law.cornell.edu/cfr/text/27/part-21

§ 21.76 Formula No. 40-B.
(a) Formula. To every 100 gallons of alcohol add:

One-sixteenth avoirdupois ounce of denatonium benzoate, N.F., and 1/8 gallon of tert-butyl alcohol.

So you probably are smelling the t-butyl alcohol.

teodor - 12-1-2023 at 03:32

I already distilled something like 10L of bitrex denaturated alcohol (but this is not your brand, I buy it in NL). The lable says there is only bitrex in addition to EtOH but I suspect there are other additives. When distill I put NaOH or KOH in the source flask and after the distillation the rest (~10% alkali solution) is usually colored orange-brown. That's why I suspect it is not only bitrex. Also the smell of the product is pure EtOH when I use this method.

SuperOxide - 12-1-2023 at 07:53

Quote: Originally posted by teodor  
I already distilled something like 10L of bitrex denaturated alcohol (but this is not your brand, I buy it in NL). The lable says there is only bitrex in addition to EtOH but I suspect there are other additives. When distill I put NaOH or KOH in the source flask and after the distillation the rest (~10% alkali solution) is usually colored orange-brown. That's why I suspect it is not only bitrex. Also the smell of the product is pure EtOH when I use this method.

Great, I'll try this. What does the NaOH/KOH do? And which would you recommend, NaOH or KOH?

Edit: I'm going to try to reprocess 1.5L of the EtOH. How much KOH would you recommend? I added 20g KOH flakes, didn't seem like it was very much tho, do I need more?

Maybe I should just add some straight up sodium metal?

[Edited on 12-1-2023 by SuperOxide]

Bedlasky - 12-1-2023 at 09:03

Quote: Originally posted by teodor  
I already distilled something like 10L of bitrex denaturated alcohol (but this is not your brand, I buy it in NL). The lable says there is only bitrex in addition to EtOH but I suspect there are other additives. When distill I put NaOH or KOH in the source flask and after the distillation the rest (~10% alkali solution) is usually colored orange-brown. That's why I suspect it is not only bitrex. Also the smell of the product is pure EtOH when I use this method.


In Europe denaturated EtOH usually contains around 1,5% MEK, 1,5% i-PrOH and 0,01% denatonium benzoate. I don't how in NL, but in CZ you can find safety data sheet online which have list of all components (or at least EtOH from Severochema have safety data sheet online, I don't know if other companies give you that).
Quote: Originally posted by SuperOxide  

Great, I'll try this. What does the NaOH/KOH do? And which would you recommend, NaOH or KOH?

Edit: I'm going to try to reprocess 1.5L of the EtOH. How much KOH would you recommend? I added 20g KOH flakes, didn't seem like it was very much tho, do I need more?

Maybe I should just add some straight up sodium metal?

[Edited on 12-1-2023 by SuperOxide]


Aldol condensation. MEK react with itself in alkaline solution to form compounds with higher boiling point. But this can't help you remove t-BuOH. You can use this method just for removal of ketones.

SuperOxide - 12-1-2023 at 09:30

Quote: Originally posted by Bedlasky  
Quote: Originally posted by teodor  
I already distilled something like 10L of bitrex denaturated alcohol (but this is not your brand, I buy it in NL). The lable says there is only bitrex in addition to EtOH but I suspect there are other additives. When distill I put NaOH or KOH in the source flask and after the distillation the rest (~10% alkali solution) is usually colored orange-brown. That's why I suspect it is not only bitrex. Also the smell of the product is pure EtOH when I use this method.


In Europe denaturated EtOH usually contains around 1,5% MEK, 1,5% i-PrOH and 0,01% denatonium benzoate. I don't how in NL, but in CZ you can find safety data sheet online which have list of all components (or at least EtOH from Severochema have safety data sheet online, I don't know if other companies give you that).
Quote: Originally posted by SuperOxide  

Great, I'll try this. What does the NaOH/KOH do? And which would you recommend, NaOH or KOH?

Edit: I'm going to try to reprocess 1.5L of the EtOH. How much KOH would you recommend? I added 20g KOH flakes, didn't seem like it was very much tho, do I need more?

Maybe I should just add some straight up sodium metal?

[Edited on 12-1-2023 by SuperOxide]


Aldol condensation. MEK react with itself in alkaline solution to form compounds with higher boiling point. But this can't help you remove t-BuOH. You can use this method just for removal of ketones.


Since the KOH is just a catalyst, I probably added too much, but it'll be fine.
I'm refluxing it now, and it seems to be working since it turned yellow (pic below) and is slowly getting darker.



[Edited on 13-1-2023 by SuperOxide]

Tsjerk - 12-1-2023 at 10:13

I think you are smelling MEK, even in pure ethanol it has a distinctive smell. I always reflux an hour or so before starting the distillation, as otherwise a good portion (first 20% or so) of the distillate will smell. I never checked how much hydroxide I used, a good dash. Probably more than 20 grams per 1.5 liters.

SuperOxide - 12-1-2023 at 18:12

Quote: Originally posted by Tsjerk  
I think you are smelling MEK, even in pure ethanol it has a distinctive smell. I always reflux an hour or so before starting the distillation, as otherwise a good portion (first 20% or so) of the distillate will smell. I never checked how much hydroxide I used, a good dash. Probably more than 20 grams per 1.5 liters.

Well, I ended up going with 30g. Since the KOH is just being used as a catalyst for the aldol condensation, I figured it didn't really need much as long as I refluxed it for a bit.

After adding 30g of KOH to 1.5L of smelly denatured EtOH, I refluxed for just over 2.5 hours, at which point it turned very dark red in color:


Now I'm fractionally distilling the ethanol. I ditched the first ~100mL that came over and I'll keep everything except the last ~200mL of nasty dark polymerized aldol condensate that's left.

Even though the distillation isn't done, I can still smell some musky odor from the distillate. So I may repeat this process again to see if it polymerizes again, and if it turns the same dark red.

Updates to come!

[Edited on 13-1-2023 by SuperOxide]

draculic acid69 - 13-1-2023 at 00:30

I'm quoting the process of a guy who turned Australian diggers brand metho aka denatured alcohol or methylated spirits into drinkable ethanol:
Firstly Oz metho contains no methanol so forget that problem
next problem is the bitrex & the mek/mibk impurity and standing over
caustic soda+stirring overnight followed by distilling gave an improved
but not yet pure product that maybe had t-butyl or isopropyl still in there which was removed by a fractional distillation. The last impurity was thought to be cyclohexane
and was removed by diluting product down to 40% with water (it turned cloudy) and mixing with cooking oil(can't remember which one) which removed a peppermint smelling impurity and clarified the cloudy liquid. There was also a carbon filtration and a distillation with heads and tails removed at some points.this is a summary of a long post but all vital points are made

unionised - 13-1-2023 at 05:34

There's a point where it's easier to start with sugar, water and yeast.

SuperOxide - 13-1-2023 at 06:11

Quote: Originally posted by unionised  
There's a point where it's easier to start with sugar, water and yeast.

If it got to that point, I would just buy a case of everclear and Dehydrate that, which is what I was doing before this denatured ethanol.

blogfast25 - 13-1-2023 at 11:59

Quote: Originally posted by unionised  
There's a point where it's easier to start with sugar, water and yeast.


Fermentations don't produce pure alcohol. Trust me, personal experience... :(:(

SuperOxide - 13-1-2023 at 21:24

Well, I've finally got it down to a decent process.I had to do a couple more cycles of adding more KOH and refluxing longer, but eventually the distillate comes over with pretty much no odor now (other than the typical EtOH odor).

Nothing left but to scale it up and process the rest of the gallon! I think now would be a great time to brag about a new purchase that I had a hard time finding. A brand new 45/50 4L Kimble Erlenmeyer flask for situations just like this :-D

I had a hell of a time finding jointed erlenmeyer flasks over 2L, so a Kimble brand 4L flask with 45/50 joint... No way could I say no to that.

I added a truckload of KOH to the denatured Ethanol in the flask, and i'll let it stir over night, then tomorrow ill reflux it (probably for the whole day), then get to fractional distillation eventually.

Thanks for the input everyone! As always, much appreciated :-)

P.S. If youre interested in an oversized jointed Erlenmeyer flask, reach out to LabProglass on ebay (very reputable vendor). They even have a 5000 mL Erlenmeyer flask available. Neither the 4L or 5L were listed, I had to ask them for them before they would list them (kinda weird, but whatever). So if you don't see what you want, just message them.

XeonTheMGPony - 15-1-2023 at 07:45

Quote: Originally posted by unionised  
There's a point where it's easier to start with sugar, water and yeast.


I'm going that method, 55 gallons at ideal 20%, sadly that's the easy part the yeast does the work there.

XeonTheMGPony - 15-1-2023 at 07:47

Quote: Originally posted by blogfast25  
Quote: Originally posted by unionised  
There's a point where it's easier to start with sugar, water and yeast.


Fermentations don't produce pure alcohol. Trust me, personal experience... :(:(


Don't know many who ever tried to drink the mash !

I prefer triple pass over a nice 4 foot packed reflux!

Lionel Spanner - 15-1-2023 at 10:50

Quote: Originally posted by Bedlasky  
In Europe denaturated EtOH usually contains around 1,5% MEK, 1,5% i-PrOH and 0,01% denatonium benzoate. I don't how in NL, but in CZ you can find safety data sheet online which have list of all components (or at least EtOH from Severochema have safety data sheet online, I don't know if other companies give you that).

European denatured alcohol is standardised as per Regulation 2018/1880, the standard recipe being 1% v/v methyl ethyl ketone, 1% v/v isopropyl alcohol and 0.001% w/v Bitrex.
A few member states use higher concentrations of denaturants, and Czechia and Greece use mixtures without Bitrex.

unionised - 15-1-2023 at 12:54

MEK forms a fairly convenient azeotrope.
Stripping out IPA would be harder, but for a lot of things it wouldn't matter.

I did discover that you can use cation exchange resin to strip out the violet dye and pyridine that they used to use.
I think it would work for bitrex too.

SuperOxide - 16-1-2023 at 16:59

Quote: Originally posted by unionised  
MEK forms a fairly convenient azeotrope.
Stripping out IPA would be harder, but for a lot of things it wouldn't matter.

I did discover that you can use cation exchange resin to strip out the violet dye and pyridine that they used to use.
I think it would work for bitrex too.

Honestly, this now is just an exercise in seeing just how pure I can get this to be. I've decided that from now on, I'll just go with Everclear, then use 3A sieves, then add in some sodium, and distill and store over sieves. That's so much less work than denaturing this crap..... Almost like that's the point? lol..

Rainwater - 17-1-2023 at 02:34

Can you do a tlc plate, find an eludent mixture that provides seperation?

Mateo_swe - 17-1-2023 at 03:11

Quote: Originally posted by blogfast25  
Quote: Originally posted by unionised  
There's a point where it's easier to start with sugar, water and yeast.


Fermentations don't produce pure alcohol. Trust me, personal experience... :(:(


So doing a fermentation using water, sugar and turbo yeast, then distilling the filtered liquid in a big distiller with column filled with ratchig rings dont produce ethanol?
Discarding the liquid coming over first (forerun) then dilute distillate to 40% and then running it through a pipe filled with activated carbon.

I have made drinkable ethanol like this a lot in the past and its way better than store bought drinkable ethanol.
This must surely be just ethanol, or am i wrong about this?
I have plans to do this again but adding a second distillation step to get it to high % and then use this for chemistry experiments.
But is this pure ethanol?
It sure is drinkable and tastes good.

unionised - 17-1-2023 at 05:00

Quote: Originally posted by blogfast25  
Quote: Originally posted by unionised  
There's a point where it's easier to start with sugar, water and yeast.


Fermentations don't produce pure alcohol. Trust me, personal experience... :(:(

Fermentation doesn't give you pure alcohol. I don't imagine anyone thought it did.

But the impurities produced by fermentaion are not specifically chosen to be hard to remove from pure alcohol.

So, if you want pure alcohol, should you start with wine or with denatured spirits?

Mateo_swe - 17-1-2023 at 05:28

OK
If i want some pure ethanol there is a product avaliable that contains this according to the safety datasheet.

Ethanol >75 - 100%
propan-2-ol 10 - <20% (isopropanol)
butanon; 0,1 - <1% (ethylmethylketon)
acetone 0,1 - <1%

Is there any easy way to purify this so i get pure ethanol for my chemistry experiments?

Bedlasky - 17-1-2023 at 06:03

You can make very pure EtOH by fermentation and fractional distilation. Look at Fery's thread about it, I run his EtOH through GC, it contain just few tens of ppm MeOH and higher alcohols. I can post reports if desired.

Mateo_swe - 17-1-2023 at 06:16

Thats nice tnx, i look into it.

I just looked at various etanol products but all contain what i specified in above post.
Exept hand disinfection alcohol, it contains just Etanol 629 g/kg and Isopropanol 63 g/kg.
But they are maybe tricky to separate.
I probably try the fermentation route to ethanol.

Bedlasky - 17-1-2023 at 07:57

EtOH and i-PrOH can be separated by fractional distilation. But I don't have any experience with it.

Fery's thread is here:

https://www.sciencemadness.org/whisper/viewthread.php?tid=15...

And here are reports from GC. He sent to me 3 fractions, all are pretty pure, the biggest impurity is MeOH, but its content didn't exceed 0,1% (MeOH is at retention time 1,5; everything else after EtOH are probably higher alcohols, in one fraction there was also some ethyl acetate).





1.png - 720kB

2.png - 709kB

3.png - 717kB

[Edited on 17-1-2023 by Bedlasky]

Mateo_swe - 17-1-2023 at 10:09

Wow, 99.9% and 99.95% ethanol.
Getting that % from fermentation and distillation is impressive and this quality of ethanol should do for almost all things.
I have made a comment in Fery´s original thread about adding a step with active carbon treatment.

SuperOxide - 17-1-2023 at 20:01

Oh boy. Well. After starting with close to 1.5L of denatured ethanol, and processing it four or five times with very generous amounts of KOH and NaOH, I can say the 700mL I got out on the other end substantially has so little amount of denaturant in it, that I can't smell it one single bit :-)

I'm also coming to the conclusion that it's so much easier/cheaper/faster/cleaner to just purchase everclear....

YOU WIN, UNCLE SAM! lol.

denatured ethanol

Nitrous2000 - 18-1-2023 at 10:36

hi guys,

I see from this thread that removing Bitrex from alcohol may be unfeasible but another source of alcohol (50% or so) are alcohol solutions tainted with propylene glycol.

This is commonly sold as antifreeze for potable water systems.

Nitrous

blogfast25 - 18-1-2023 at 12:41

Quote: Originally posted by Mateo_swe  
Wow, 99.9% and 99.95% ethanol.
Getting that % from fermentation and distillation is impressive and this quality of ethanol should do for almost all things.
I have made a comment in Fery´s original thread about adding a step with active carbon treatment.


It also seems impossible w/o 'breaking' the EtOH/water azeotrope?

unionised - 18-1-2023 at 14:41

Quote: Originally posted by Bedlasky  


And here are reports from GC. He sent to me 3 fractions, all are pretty pure, the biggest impurity is MeOH, but its content didn't exceed 0,1% (MeOH is at retention time 1,5; everything else after EtOH are probably higher alcohols, in one fraction there was also some ethyl acetate).


[Edited on 17-1-2023 by Bedlasky]


Does the GC detector detect water?
(It looks like an FID trace to me)

blogfast25 - 18-1-2023 at 18:32

Quote: Originally posted by unionised  

Does the GC detector detect water?
(It looks like an FID trace to me)


No detection, no water. Simples! :D:D

Bedlasky - 19-1-2023 at 00:08

Quote: Originally posted by unionised  
Quote: Originally posted by Bedlasky  


And here are reports from GC. He sent to me 3 fractions, all are pretty pure, the biggest impurity is MeOH, but its content didn't exceed 0,1% (MeOH is at retention time 1,5; everything else after EtOH are probably higher alcohols, in one fraction there was also some ethyl acetate).


[Edited on 17-1-2023 by Bedlasky]


Does the GC detector detect water?

(It looks like an FID trace to me)


No, it doesn't. As you say - it have FID detector, so it can't detect water. We have in job one GC which have different detector and can detect water (it is used for water determination in aniline and cyclohexylamine). I determined water content on KF titrator. According to KF titration it have 6,5% water, but Fery's distilate came over exactly at boiling point of azeotrope, so I don't trust this value much.

Mateo_swe - 19-1-2023 at 05:01

Im more intrested in the contaminating stuff than water content.
Its not so hard to remove water up to 95% and if absolute ethanol is needed it can be done as well.
Removing contaminants are harder if they have similar boiling points.
But it looks like Fery´s procedure give very low levels of contaminats so i think thats the way to go for me.

Buying drinkable ethanol is an option but there is probably some contaminants in this too, just not any that is dangerous when consumed.
There are a few places that sell absolute ethanol at higher cost, it might be worth it depending on how one values the time and effort it takes to get to absolute ethanol with DIY routes.
To get 95% pretty pure ethanol maybe distillation of drinkable ethanol is an option.