How long is Biodiesel good for once it is made? I Thinking of trying it in my home heating system as well as my 6.0. If I was to make alot over the summer and put it in my home heating fuel tank will it separate or anything like that? Or does anyone know the shelf life?

Thanks
Attilak

 

Anyone?

Does anyone know how long Biodiesel will last once it is produced?

What is it's shelf life?

Does it lose it's strength?

Thanks
Attila K

 

The information I have read says 6 months to one year. Keep it dry (tightly closed drum) and out of the sun. Bio made from WVO actually has a longer shelf life than Bio made from new oil. Go figure.

 

BD doesn't "lose strength" over time. The problem with long term storage is oxidation.
it produces organic acids that can attack metal parts in your fuel system. Fuel quality has a major impact on the speed at which oxidation occurs.
Oxidation can be controlled by several methods, all of which add cost to your BD; however, the best and cheapest control is keep storage to 45 days or less.

 

Phydeaux,

What other ways can used to control oxidation, besides short storage?

 

1. Do not store in unlined steel containers.
2. keep the head space filled with dry Nitrogen.
3. Do not use heat to dry your fuel (Magnesol wash instead of water eliminates need for drying)
4. Do not expose to sunlight (use opaque staorage containers)
5. Drive the conversion reaction as close to total conversion as possible. (Pull glycerin off from time to time during the process)
6. Hydrogenate the BD to close double bonds.

Some of these are more practical than others for an individual, but they all work and in combination can greatly extend storage life.

 

I am new to BD

What do you mean by "6. Hydrogenate the BD to close double bonds."

Which of your methods is most practical or most cost effective ?

 

Unless you have a little background in organic chemistry it is hard to explain but I will give it a whirl.

Carbon atoms bond to other atoms by sharing one of its electrons ( each atom donates one electron to make the required bond pair).

Each Carbon atom has 4 electrons that can be used for bonding so a carbon atom can bond to 4 other atoms.

A Hydrocarbon is made up of 1 or more carbons atoms (if more than one they form a chain) all electrons in the carbon atoms not used for carbon - carbon bonds are used for carbon - hydrogen bonds.

The simplest hydrocarbon is methane it is a single carbon bound to 4 hydrogens and can be depicted as

........ H
.........'
.....H-C-H
.........'
........H

The next hydrocarbon is Ethane 2 carbons bound together surroundes by 6 Hydrogens

.....H H
......' '
..H-C-C-H
......' '
.....H H

Next is propane

......H H H
.......' ' '
...H-C-C-C-H
.......' ' '
......H H H

See the chain forming? and it goes on from there

Once in a while two adjacent carbons will each shed one of their atoms and form a double bond with each other, that is each atom contributes 2 electrons to the bond (a total of 4 involved).

.....H H
......' '
.....C=C Ethane becomes Ethene
......' '
.....H H


Double bonds are stronger than single bonds but not twice as strong. It is not difficult to break one of the bonds and introduce other molecules. Some of these other molecules cause problems, that I don't have the room to discuss here, but one of the problems is polymerization in which two long hydrocarbons each with double bonds will join together at those bonds forming a single much bigger branched molecule. If each molecule has more than one double bond this process can be repeated forming huge very complex molecules, that is how plastic is made. But as the molecules get bigger they become more viscuss and can plug up things like fuel injectors.

Biodiesel made from certain vegetable oil feed stocks like canola are loaded with double bonds (any oil referred to as unsaturated has them).

Over time these oils can start to polymerize and that will cause major problems.
To prevent that the oil can be hydrogenated, all the double bonds broken and filled with hydrogen. Than is not difficult to accomplish if you have the equipment and it boils down to bubbling hydrogen gas thru the oil under the right conditions.

 

Bubbling hyrogen gas through the oil under any conditions does not sound like something I want to do. That doesn't sound very practical.

Whats the most practical way to extend the shelf life of newly made BD ?

 

Now that the mind numbing part is over, the easiest and cheapest way to control problems, besides limiting storage to 45 days, are 1, 3, 4, & 5. They're not expensive, they dont take extra time, and they are effective.

 

Now that the mind numbing part is over, the easiest and cheapest way to control problems, besides limiting storage to 45 days, are 1, 3, 4, & 5. They're not expensive, they dont take extra time, and they are effective.