I was reading it briefly to check if there are any special things to consider, but the first impression is that it is not quite different than other TEKs when handling the Naphtha in the end.
So normally you should reduce it and then freeze precipitate. And now you simply ask what happens if you just evaporate everything?
Thats just fine, nevertheless the idea about freeze precipitation is that this would grant a product with higher purity and also higher crystalinity.
Crystals may either form if the solvent is suddenly removed and the dissolved molecules are forced to solidify. Another way is to reduce the max capacity of dissolved components in the solvent - so the solvent is not capable of holding all the molecules anymore and will consequently drop them as a solid.
The main advantage of using the second way (freeze precipitation) is that this is a more defined and controled process, therefore the crystal growth is also more defined and this will produce very beautiful structures usually. A second advantage is that even as Naphtha should not catch up many impurities, there will still be some. And by freeze precipitation these impurities are mostly staying in solution. This means your Naphtha retrieved by this way will not incorporate them into its crystal structure, therefore it will be more white this way.
On the other hand a disadvantage of Freeze Precipitation is that the solubility of DMT just drops, but does not go to 0. This means even at - 20°C there is a tiny bit of DMT still inside the Naphtha, that would be lost when pouring it away (preferably not into the drain because of environmental issues). At - 20°C the solubility of DMT is ~ 130 mg/100ml so if you have 200 ml Naphtha then you would miss out 260 mg of DMT.
Either way you will not make any mistakes, but if you already evaporated all the Naphtha, check if you are pleased with the purity. If the DMT is strongly coloured brown, you may do a recrystalization. It may even be an oil and not even solid, this may be a stronger reason to purify it, as this will not only be a cosmetic issue, but also greatly reduce the conveinience when handling it.
