Hi everyone, I am new to this forum and to making biodiesel ( have not made any yet). I am in the West indies and it is hard sourcing methanol here. I was wondering, since isopropyl is used in the titration can it be used in the manufacturing of biodiesel as a substitute to methanol?

G'day novice2;
Welcome to the forum. Methanol is also known as many other names that can be found here.
Don't know about Isopropyl though,maybe sopmeelse will chime in.

Quoting from this thread ---

http://biodiesel.infopop.cc/eve/forums/a/tpc/f/9601000031/m/1371045841

As i understand it, you cant substitute ispropanol for methanol in a standard base catalysed reaction as the alcohol must be straight-chained (thats why you use ipa for titration - it doesnt react.

If in doubt, try a 1L test batch -- see what happens!

Chris

Thanks Legal Eagle and Chris da Pirate for your links guys.

I will give it a try Chris.

Don't waste your time. It doesn't work unless you are trying to make vegie jelly.

Randy

Probably about the 50th time this question has been asked...

No.

novice2 - if methanol is difficult to find, try locating some ethanol. It will have to be very pure, much more pure than anything used for drinking. Distillation will leave a few percent water, even after multiple distillations. Small amounts of water with ethanol will prevent the reaction and result in a bunch of soap.

However, ethanol is being used as a source of fuel more and more, and dry enough ethanol may be locally available and sold as fuel. Don't worry if it has some benzene/gasoline added - this will be ignored by the reaction, as long as you compensate for the gasoline by just using more (and there is no water contamination!) Start with 300 to 350 ml of ethanol per liter of vegetable oil (oil that has no water!) NaOH dissolves slowly in ethanol, but it will dissolve. You can use a food blender to speed the mixing of ethanol and NaOH, and when you are done you can even wash the blender and re-use it! This would not be advised if using methanol (or ethanol plus gasoline), as it is quite nasty.

I have made many good 1 liter batches of biodiesel with ethanol sold in hardware stores as 'denatured alcohol'. It is important to understand that as soon as you open a sealed container of ethanol that it will start sucking water out of the air, so it is best to use an entire container very quickly once it as been opened. Make a small test batch, and as soon as you have confirmation of a good glycerine 'split' (within an hour or so), use up the rest of the ethanol. If it sits even for just a few days in a half-empty container full of air, then it may become contaminated.

Ethanol drying is a booming business nowdays. 3A molecular sieves, a form of zeolite, are often used, and I've seen references to pervaporation membranes also being used. Molecular sieves and membranes generally require an industrial process to make work safely, but there are even simpler ways of drying ethanol that would be fine for a hobby biodiesel maker. Simply add some lime based plaster, or quicklime, to the ethanol, stir well, seal in a container with very little air space, and let it settle for a few hours or days (or filter it). The calcium oxide in the lime will react with the water in the ethanol and form calcium hydroxide, which will settle to the bottom along with the unused calcium oxide. You'll be left with de-watered ethanol that has a lot of fine particles of lime floating around in it. This won't hurt the reaction and will make fine biodiesel, but you'll want to filter the particles out very well before dumping in an engine. Oil lamps won't care though

So even if you cannot find a local source of dry ethanol, I bet you can dry it yourself. Just think, you'll be saving the environment and a drunk at the same time.

Good luck!

Dan