So what are the issues? Anything other than reduced yeild?
What are the tips/tricks to getting good bio with paritally hydrogenated oil?
More heat? More NaOH/KOH? More Methanol? Longer processing?

I have a chance to pick up about 50 gallons of free oil but 40 of it is "partially hydrogenated" according to the guy wanting to give it away.

So is it worth the effort to go get it, or not? Can good bio be made from this kind of stock without going to some kind of extreme measures?

 

I use it all the time. I blend all my WVO sources together. I've never noticed any difference, other than the Hydrogenated oil is thicker at colder temps. No difference in the bio though.

 

Thanks Fab. Thats pretty close to the answer I got on one of the other boards I'm on. A guy there responded and said it raises the cloud point of the bio a little, but other than that, and the oil having to be heated to liquify before going into the processor, there's really no difference.

 

Do you understand the difference between saturated and unsaturated VO?

 

Phydeaux, good to see you on the forum again. Hope all is well.

 

Thanks Trent.
I am doing well so far.

 

I've read a little, but don't recall the details. Seems like it was something to do with whether or not all the ends of the HC chains had as many H atoms as they could hold. If so they are "saturated" with hydrogen (a.k.a. hydrogenated)...

But my memory (or understaanding) may be totally wrong. Care to refresh my memory, oh chemist buddy 'o mine?

 

In saturated hydrocarbons each carbon atom is bonded to 4 other atoms, usually 2 other carbons and 2 hydrogen unless they're carbons at the end of the chain then they are bonded to 1 carbon and 3 hydrogens. Each bond is made up of a pair of electrons which the two atoms share.

In an unsaturated hydrocarbon at least on pair of carbon atoms share a double bond (an extra pair of electrons involved). In that case the carbons involved will each give up one of the usual hydrogens. Double bonds are more unstable than single single bonds and are the sites at which oxidation and polymerization occur, thus they are undesirable to a certain extent; however, they also have some beneficial qualities in that they tend to lower the cloud point of BD. As you can see it is a mixed bag of benefits some good some bad.

Hydrogenation is the process by which unsaturated hydrocarbon molecules may be converted to saturated, or fully hydrogenated, molecules.

All in all there is no reason to not use saturated or hydrogenated VO to make BD. It will be less likely to deteriorate thus will have a longer storage life but it will have a higher cloud point and will need precautions in cold weather.

 

WOW! My memory is better than I thought! I pretty much had it right! I'm not much of a chemist - only took 2 semesters of it in college 10-12 years ago - plus I only read one article on hydrogenation and saturated vs unsaturated fats! HOORAY FOR ME! Maybe my memory isn't slippin' as bad as I sometimes feel like it is

Thanks for filling in some of the finer points and details Phy. I can always count on you to help bring chemistry back down to a level that us non-chemists can get our heads around.