Has anyone tried using biodiesel as a solvent? Apparently it works just as well as some other nps's minus the toxicity, psychoactivity, carcinogenicity, etc. Not to mention its easy to make in large quantities.

Source?

http://www.thesietch.org/faqs/biodieselfaq.htm






Study on the Solvent Power of a New Green Solvent:  Biodiesel

Jianbo ,* Zexue , Zhong Tang , and Enze
Research Institute of Petroleum Processing, SINOPEC, Beijing 100083, China
Ind. Eng. Chem. Res., 2004, 43 (24), pp 7928–7931
DOI: 10.1021/ie0493816
Publication Date (Web): October 30, 2004
Copyright © 2004 American Chemical Society

Biodiesel is an ester, usually a methyl ester. When used to extract a strongly alkaline solution, might the biodiesel not hydrolize (saponify) into the free fatty acid, that works as a soap and causes ugly suspensions?

I also doubt that it can be used for freeze precipitation, nor will it evaporate easily, unless you use something like ethylacetate, which is also an ester.

If the above assumptions hold, you might be able to use biodiesel in an acid/base extraction (using only mild base) that is backsalted, reduced, based and dried for final extraction with dry alcohol and evaporated for product. But straight to base and freeze precipitation would not work so well.

You may want to try ethylacetate. Ethylacetate has all the green properties of biodiesel, is a great solvent and commonly used in nail polish remover (loaded with perfume though - hmmm, perfumed DMT....).

Your probably right though it could be used to defat.

Defatting is generally a waste...

That's not entirely fair, it just depends on what you're working with. I defat all my Hawaiian Baby Woodrose seeds before getting to work on the meat of the extraction.

Most hydrocarbon solves evap clean though, which is really convenient. Given how easy it is to take care and not poison yourself with them (wear gloves, do it in a well ventilated space, don't juggle fire over the plate, etc), I'm not sure the extra work of dealing with the biodiesel is worth it.

Good find though. Made for some great readings.

Allow me to rephrase...

For A/B (or similar) extractions, defatting is generally a waste.

But biodiesel is mostly man-made using a fair amount of synthetic chemistry.

Wouldn't you be safer using naphtha which is distilled off petroleum, the latter coming straight out of our mother-earth?

Petroleum distillates almost always contain small amounts of carcinogens not to mention lots of hydrocarbons are carcinogenic in and of themselves. Biodiesel could only contain alkyl esters, water, alcohol, glycerine, glycerides, soap, traces of NaOH, and stuff like that. Properely made biodiesel should only contain alkyl esters, alcohol, and traces of glycerides. Totally harmless. You could probably drink the stuff and be fine(I wouldn't though). Try that with naptha and see what happens. Just because something is natural doesn't automatically make it better.

I was only taking the piss my man, please accept my apologies

But btw, just as you mention the carcinogenic (of generally harmful for that respect) potential of petroleum distillates, how about the safety profile of e.g. alkyl esters? are they as safe we think they are because of the bio- prefix or is there more to it?

In any case, there are several people who have used vegetable oils (or let's just say a precursor to biofuel) to do successful extractions which may rank higher in the safety profile.

Nothing beats xylene and dcm though

Very true. If only we all had the access to thos chems. That would be wonderful world. Actually that would be kinda dangerous but whatevs

I would love to know what the breakdown products of biodiesel and their safety.

Have any links to vegetable oil extractions?

The search function might be helpful for you.

This post caught my eye because I am working only with sunflower oil, and it works well but can be a bit tricky at times, so finding a way of making veg oil into a better solvent would be great. But after looking at the process of actually making biodiesel, the extra effort seems to out weigh the possible benefits. Rather just start using veg oil if you want to go the eco route and just work out all the kinks in your tek.

i got some good advice in this thread. Am gonna post a pictorial once i finish my current extractions. There seems to be a lack of decent success stories with veg oil in the forums so that should be changed ;-)

Consider adding limonene to safflower oil to help lower the viscosity. I did a couple of mescaline extractions some years ago using a solvent that was like 1:3 limonene:safflower and it worked quite well for oil. Toluene is still outstanding though...

In an alkaline environment, they would be methanol and the anions of whatever fatty acids are involved. This should be fairly clear if you know that biodiesel almost always consists of methyl esters of fatty acids.

Methanol is toxic and methyl esters hydrolyse fairly easily, so the caveat about working quickly at room temperature and avoiding excessive mixing applies at least as much as with veg oils.