Greetings fellow nerds.
This is another lab notes video on making sodium and so far we've have had a very interesting few months.
Briefly i've been trying to make sodium by reacting magnesium metal and sodium hydroxide, in mineral oil with a tertiary alcohol catalyst.
There have been lots of issues that i've documented in past lab note videos.
Including trying to find a workable solvent, reaction times, processing methods in dioxane, preventing glassware destruction
and trying to dry the reagents using easy to obtain drying agents like aluminum and lithium metal.
In a recent video i explored various alternative catalysts for the sodium production reaction and one of the more promising candidates was tea tree oil.
Easily purchasable and relatively cheap.
But upon further testing it was determined that it wasn't very good and gave poor yields.
It was actually worse than the thermochemical dioxane process which is currently our benchmark for how well we're doing.
We have to at least beat that for this to be worthwhile.
One hypothesis for the poor yields was that this alkene functionality in the 4-terpineol was the source of our problems.
Another hypothesis was that the 60% other chemicals in tea tree oil like gamma terpinene and so on were the problem.
It might even be both.
Whatever solution we wanted to test, either hydrogenation or distillation, i wanted to have a large quantity of tea tree oil to make the process easier.
So i ordered some and finally here it is, one liter of tea tree oil.
Since it's easier for the amateur to fractionally distill than it is to hydrogenate alkene groups we'll do that first.
So i took my tea tree oil and poured it into a large flask.
And then setup a full sized 100 centimeter fractional distillation column.
Unfortunately i couldn't fractionate this.
The components in tea tree oil have too high a boiling point and even after a few hours of heating my hotplate just wasn't hot enough to push the vapors all the way through.
So i disassembled the full sized apparatus and assembled a smaller sized one.
I'm using a dimroth condenser as a fractionation column since it has more surface area than a simple straight column.
There is no coolant in it and it's just for fractionation.
I then proceeded to start the fractional distillation process and things worked much better this time.
I covered the apparatus in aluminum foil to keep the heat in since even with a shorter column it still wasn't hot enough to boil through.
Most of the lighter boiling impurities are terpinenes.
As well as some 1,8-cineole.
Various types of tea tree oil is different depending on the source, the region, the weather, even the soil from which the plant is grown in.
So i can't really say exactly what chemicals we have and how much.
Thus, i didn't bother trying to isolate individual fractions at this point.
Another difficulty is that with such a small fractionating column we're not going to have very good fractionation anyway.
There was going to be a lot of overlap of the chemicals.
But i'm hoping we can get much better purification than 40%.
So i boiled off everything all the way up to 213 celsius which is the lower boiling range of our target 4-terpineol.
I'm not going to throw this stuff away, there is likely a lot of 4-terpineol overlap, and i'll try and recover that with a better apparatus eventually.
But for now to save time i just collected whatever i could between 213 celsius and 218 celsius which was the boiling range of 4-terpineol.
It won't be pure due our poor fractionation ability with a short column, but hopefully it'll be pure enough to give us better performance for making sodium.
I collected a total of 250mL out of an expected 400mL.
Hopefully this means we didn't collect much impurity overlap.
I'd much rather have a small amount of pure product than a large amount of impure product.
Now to actually test it.
I setup another half scale sodium production run with 20g of sodium hydroxide, 15g of magnesium metal, 3g of sodium metal jumpstart and 150ml of mineral oil.
I initially injected 1.2mL of purified 4-terpineol, and as usual i ran through the usual drying procedure and went to operating temperature.
Good hydrogen formation followed and went on for about 22 hours before stopping and back flowing.
Bubble rate was about the same as my other runs so it doesn't seem much better than unpurified tea tree oil.
I then cracked it open the apparatus and injected another 1.2mL and this time things worked much better.
In my previous experiments after an initial burst of hydrogen after the second catalyst injection the reaction shutdown again in less than 30 minutes.
But this time it kept going for another 20 hours.
Afterwhich I injected it again but it shutdown after 30 minutes so i assume that was when the total reaction stopped.
I then poured off the slurry into a sieve and things look great.
We're getting a large globule of sodium magnesium alloy which i hope is more sodium than magnesium this time.
Again i boiled in dioxane to separate the sodium and here we are.
This looks much better than our original attempts.
So it turns out it really was the impurities that inhibited further reaction and destroyed our yield in our experiments with unrefined tea tree oil.
Now 4-terpineol isn't perfect, it seems to decompose before the reaction is finished so you need to inject a second shot to continue.
But considering how cheap it is this is not a problem.
I think the decomposition has something to do with alkene group indeed polymerizing and creating a non-catalytic species.
Nonetheless the next logical experiment would be to test if we used a greater starting quantity of catalyst would it last long enough to finish the reaction.
So I redid the experiment with the exact same conditions except rather than starting with 1.2mL of 4-terpineol i added in 4 mL of 4-terpineol.
Hopefully it'll finish faster with the extra catalyst, or have enough catalyst to last until the end of the reaction.
Either way we should get a good yield by the time reaction stops.
There is a third option though where the rate of the sodium production reaction is unchanged but the catalyst still decays at a constant rate as the decay mechanism is independent of the sodium production mechanism.
In this case the catalyst will still decay in 24 hours and we'll still have reduced yield.
Luckily that doesn't seem to be the case.
For this run the reaction ran for a solid 40 hours before it started to backflow.
I then proceeded to process the reaction as usual with dioxane and this time i got a yield of 12.4g.
Since i started with 3g of sodium metal our actual yield is 9.4g for a yield of 81%.
You know what 81% is acceptable in my opinion.
I think we have a viable amateur accessible catalyst.
I then ran another experiment this time using a lithium metal jumpstart of one energizer AA battery along with our usual half scale reaction of 20g sodium hydroxide 15g magnesium, 150mL mineral oil and 5mL this time of 4-terpineol.
The reason why i'm testing it with lithium is because i'm not sure if lithium would react differently to the alkene group than sodium does.
Lithium is a considerably stronger reductant than sodium so there is a chance it can access undesired reactivity.
But once again things proceeded very well and after about 40 hours the reaction stopped and backflowed as expected.
I processed the reaction again by boiling in dioxane and after recovering the sodium we got 10.4g or about 90% yield.
The improved yield likely came from using even more 4-terpineol and because i was a great deal more careful in performing the reaction this time.
But nonetheless it works.
So overall it looks like we've overcome a very big hurdle, where to get the catalyst.
So far i've been using 3-ethyl-3-pentanol which works beautifully for this reaction but needs to be custom made.
While making tertiary alcohols by the grignard reaction is within amateur ability, it' still notoriously unreliable and frustrating even if you're a professional.
Being able to get a catalyst directly from a domestic source and only needing minimal processing to make it work is a major win for the amatuer.
You know what, I think we're almost done.
We've solved every problem.
We have an easy to get solvent, baby oil.
We solved the glassware destruction problem with sodium drying, and now we have solved the important problem of all, getting an easy to obtain catalystů 4-terpineol obtained from fractionally distilled tea tree oil.
At this point we can stop and make our final condensed video.
But i'm going to go a little further.
Fractionally distilled tea tree oil is great but still very far from perfect.
It decomposes during use so you need to use large amounts of it.
And fractionally distilling something at over two hundred degrees celsius is not easy.
It was actually at the very limit of my apparatus.
Amateurs with lesser setups might simply be unable to perform sufficient fractionation.
So i'm going to keep at it just a little bit longer and try to find a directly usable catalyst.
One which doesn't require any additional processing.
A few alternatives i'm going to try include cetyl alcohol and stearic acid.
I might also even try hydrogenating 4-terpineol to remove the alkene functionality.
Now I know hydrogenation would make things even more complicated again.
But if the performance is dramatically improved without decomposition then it might be worth it.
I actually think you can hydrogenate tea tree oil directly and remove all the alkenes and inhibiting impurities.
In that case we wouldn't even need to fractionally distill and just use the hydrogenated tea tree oil directly.
We'll see how things go.
But confirming that 4-terpineol distilled from tea tree oil works is still a big step forward.
Even if i totally and completely fail to find a new catalyst, we're still good in that we can fall back on this one.
So lab gods, do your worst, we've already won.
Okay moving on, we have a giveaway update for the model kits i was telling you about in a previous video.
Here is the list of top patrons, as well as lucky patrons and subscribers which were randomly selected to receive a kit.
I've already messaged and emailed all of you.
If you haven't received a message, please check your email or spam folders or message me back on the corresponding patreon or youtube account.
If you're paying close attention you might notice i have 6 youtube winners when i said there should only be 5.
Well Simon Bitdiddle who was entitled to a kit told me to donate the kit to another deserving soul.
So everyone say thanks to Simon Bitdiddle for his act of generosity.
Thank you very much you're a good man.
As for the rest of you, you can still purchase the model kits directly from the website at realatoms.com
Anyway, thanks again for being my patrons and subscribers.
I may have more giveaways in the future.
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