creating bio diesel

[TINNY]

frankly, i've never conducted any lab experiments other than in my school and you should note the lack of facilities in malaysian schools. I don't know much about high-end labs.
but my guess is that it is perfectly fine because the temperature needed is only 150 degrees and 20 psi pressure.
but be careful when you do the esterification part. once, i reacted glycerol with lauric acid in a pyrex with a bunsen burner at full blast plus extra catalyst and the mixture 'exploded' and shot up the pyrex (i donl't know the name of the apparatus in English so i'll just call it a pyrex) and showered me and a few friends with a slimy - oily goo. the cork bounced off the ceiling, table, everywhere. no joke!

[Tim_Lou]

i found an interesting website...
it says that biodiesel isnt needed... the people actually use plain oil to operate engines instead!
http://www.greasel.com/faqs/conversi...m#cookoilpower
"How can cooking oil power a diesel engine?
Chemically, vegetable oil and diesel are very similar. Both will combust via compression and heat. The major difference is viscosity. The lower the viscosity, the more fluid, or thin, the fuel. The key to getting SVO viscous enough to flow properly through an injector is heat. Our kit utilizes waste engine heat to lower the viscosity of the SVO, prepping it for it's violent journey through the tight confines of the injector."

the cost would be way cheaper if plain cooking oil is used instead of diesel...
the problem is that the oil might freeze in a cold day.

[TINNY]

ahhh.. but Tim, be careful with those one-off sites. you didn't notice that you had to use of their special kits and all sorts of precautions. here's what i got from biodiesel.org -

Raw or refined vegetable oil, or recycled greases that have not been processed into
biodiesel, are not biodiesel and should be avoided. Research shows that vegetable oil
or greases used in CI engines at levels as low as 10% to 20%, can cause long-term engine
deposits, ring sticking, lube oil gelling, and other maintenance problems and can reduce
engine life. These problems are caused mostly by the greater viscosity, or thickness, of
the raw oils (around 40 mm2/s) compared to that of the diesel fuel for which the engines
and injectors were designed (between 1.3 and 4.1 mm2/s). To avoid viscosity-related
problems, vegetable oils and other feedstocks are converted into biodiesel. Through the
process of converting vegetable oil or greases to biodiesel, we reduce viscosity of the fuel
to values similar to conventional diesel fuel ( biodiesel values are typically between 4 and
5 mm2/s).

[Tim_Lou]

well, every problem has something to do with viscosity, hehe, njyothi_srm, if you can solve the problem, it can be big money $$$$$.

[Tim_Lou]

hmm... but it looks like impossible.
since the molecule size of cooking oil is way bigger than that of biodiesel...
London forces cant be reduced, can it? by heating?

[TeleMad]

Originally Posted by Tim_Lou

hmm... but it looks like impossible.
since the molecule size of cooking oil is way bigger than that of biodiesel...
London forces cant be reduced, can it? by heating?

In general, London dispersion forces - being the weakest of the intermolecular forces - are easily overcome by heating: that's why molecules held together only by London dispersion forces (such as O2 molecules, H2 molecules, CH4 molecules, CO2 molecules, etc., and even octane) have such low melting (and usually boiling) points.

As you point out, though, the strength of the intermolecule attraction generated by London dispersion forces does increase with (1) increasing molecular mass and (2) molecular linearity. So having larger molecules in cooking oil does pose a problem. But at least with cooking oil - as opposed to fats used for cooking, which come from animals - the fatty acid chains are unsaturated and therefore contain one or more double bonds that help reduce the London dispersion forces between them by generating "kinks" in the molecules.

Keeping in mind the two things that cause London dispersion forces to increase in strength, ways to reduce the intermolecular attraction between cooking oil molecules would be to make them less linear (oxidation, to create more double bonds) and/or shortening the molecules ("cracking").

PS: Don't know exactly what good any of this does here, if any, because I didn't read any of the links or try to follow the discussion.

[KickAssClown]

I did some extensive research using the very source you've sighted.

You don't want to do it via straight Veggy oil because it cloggs the engine and you need to make alterations, specialized alterations, to the engine to get the fuel to work properly. If you use the Fool proof method or any of the Methal Oxide methods. It's pretty Safe and you can stick it into a standard Diesel Engine without adjustment. Though a fuel injector (I think) adjustment gives better performance.

Bio Diesel is actually cleaner and better for your engine and can be used to grease your engine and tools. It has a lower viscosity and Fricition co-efficent than standard Diesel.

The Ethanol methods are slightly different fish. As they have an inherient Explosive quality to them. Overall I would expect the processors to be a good fit for lab. for highest Performance I would suggest the Fool Proof method. Though it's complicated so you may want to start with the lower (easier) Methanol Methods.

[dagaz]

A few years ago a friend of mine actually had a small ute (utility) running off vegetable oil. He had this elaborate but shonky system (he was living off the dole at the time) where he had 2 40 gallon drums tied to the front of the utility tray with hoses going into the engine bay. He would actually start the car using normal diesel but then when he got it up to the proper operating temperature he would pull over, pull a lever and begin running on the used vegetable oil. Sadly the car got ruined in a flood (quite common in the town of Lismore) and because it had been so extensively modified his insurance company wouldn't cover it.

Biodiesel is becoming a bit of a buzzword in Australia - I have also seen the promotional vehicle used by the Biodiesel Association of Australia.

This page has a story of a family in outback Oz who actually use biodiesel to run their family car.

[KickAssClown]

cool.

Straight Veggy oil though is not as effienct as Methyl esters (biodeisel). Not to mention the excess glycerine and soaps you get can be put to other uses. The home processing method becomes very useful if you run a farm.