Question.............If Camelina has a higher Iodine content than canola, is there an effective chemical process to lower the Iodine Value?

 

Do you want to extract it from the oil after squeezing?

 

After a litle research here is what I can tell you

There seems to be a misinterpretation of the term "Iodine Value" or IV here.

It does not refer to the iodine content of the oil but to the results of a test used to determine the the level of saturation of an oil.
Saturation refers to the number of double bonds present in a Fatty Acid chain, saturated = no double bonds unsaturated = 1 or more double bonds.
Iodine is bubbled thru the oil, it breaks any double bonds present. Each double bond that breaks binds 2 iodine molecules to the FA. The more iodine consumed the higher the number of double bonds and the more unsaturated the oil. Iodine Value (IV) indicates how much iodine is consumed thus the level of unsaturation. The untested oil has no iodine content.

Saturation, or better put Unsaturation, is both good and bad news.
On the good side the more unsaturated the oil the lower its' cloud point.
On the bad side the more unsaturated the oil the greater the potential for oxidation and/or polymerization.

This article explains it better than I did
http://journeytoforever.org/biodiesel_yield.html#iodine

Camelina oil is very highly unsaturated with an IV of about 144 because of that it could be problematic for use to make BD; however, the problem is easily resolved, by simply bubbling hydrogen thru the oil you can reduce the saturation to acceptable levels.

Everything I have read about Camelina oil is very promising.

 

Another option would be to blend the Camelina oil with say canola oil to reduce the per gallon total iodine. No reason you couldn't do that to meet standards is there?

 

Wheatina

Are you talking about reducing the Iodine Value by blending, if so I am not sure that would work well. The more double bonds in an FA chain the more reactive it is. While blending would reduce the number of reactive molecules per gallon it would not reduce the reactivity of each molecule. Some of the reactive molecules will oxidize when you reach a critical concentration the polymerization cascade will start and you will have a mess.
By hydrogenating the FA chains you reduce reactivity of each molecule

 

I guess a better term for what I'm talking about would be to "dilute" the iodine levels rather than "blend".

For example, say you have 100 gallons of BD made from canola oil with an IV of 94. You mix that with 100 gallons of BD made from camelina with an IV of 144. So, with the two mixed, wouldn't the ending IV level be 119? Europe's requirement is <120 IV...wouldn't that make it acceptable??

 

Wheatina

I think you are mis interpreting the term Iodine value.
Go back to that long post above, the one that starts "after a little research". Read it carefully and you will see that Iodine Value (or IV) does not refer to the Iodine content of the oil. In fact there is very little naturally occuring iodine in camelina oil.
IV is an indicator of the number of double bonds in each FA chain. It is these double bonds that are the worrisome factors because they provide reactive points where oxidation and subsequent polymerization can occur.

 

Ohhh....Okay....LOL!!! I should read things. I see what this is talking about now. The concern also seems to be primarily for burning straight veg oil without any refining, too, and not talking about biodiesel so much. That IV term is a little unfortunate since it results in some confusion, but I do understand what it means now.

Sorry for not reading things as I should have!!

If you use camelina to make biodiesel, the IV factor shouldn't be much of a problem...right?? At least that's my understanding from the discussion about the difference between straight veg oil and biodiesel.

 

Wheatina

The IV factor is only a problem because it indicates that camelina oil is very subject to oxidation and polymerization, both of which reduce the storage life of BioDiesel made from camelina oil. The European standard cited sets the maximum IV at 120 so it can be predictably stored for a reasonable period of time. Since the European standard is accepted world wide it is reasonable to believe it is valid.
Fortunately lowering the IV to an acceptable range is easily accomplished by hydrogenating the oil before running it thru the transesterification process, so the hysterical response, I found on on the web page you posted in a different thread, stating that "Camelina Oil is fine for making paint but no good for Biodiesel" is wrong. all you have to do is hydrogenate it.

 

phydeaux, discuss polymerization, and the effect on diesel fuel. I have been away from organic chemistry for a long time.

 

Books have been written on this subject. I will keep it as simple as possible to avoid overpowering the FTE web site.

I am not an expert in polymerization chemistry but I do have a pretty good background in biochemestry and it is a subset of organic chemistry for all practical purposes.

Hydrocarbon chains often contain double bonded carbons within the chain.

These double bonded sites are very reactive and will form bonds with atmospheric oxygen (oxidation) producing extremely reactive peroxides. The peroxides are trouble makers. They react with the esterbonds of other biodiesel molecules forming very long chain often branched molecules (polymerization). If allowed to procede unchecked, the end result will be a significant increase in viscosity of the biodiesel causing filter plugging and pump failure.

Additionally, Peroxides are acidic in nature so they can and do attack and destroy metallic fuel system components.

Oxidation is certainly not desirable in Biodiesel fuel it can be greatly reduced by using feed stock oils with lower IV scores.

 

Phydeaux88, regardless of whether Wheatina misinterpreted what the IV number means, her logic still seems to hold water to me.

If the IV is a measure of the NUMBER of double bonds per volume of oil (ie a quantitative measure), then how is her example of mixing equal amounts of two oils with IV values of 94 and 144 and ending up with a mixture of oil with an average IV of 119 wrong?

Although it does not reduce the IV number of the camelina oil itself, it does "dilute" the concentration of double-bonds in the end product - compared to the concentration in the camelina oil. Though I guess you could look at it from the other perspective and say it raises the concentration of double-bonds relative to the canola oil.

The whole point being that the IV number can be brought into an acceptable range by blending - which is something anyone can do. Whereas hydrogenating camelina oil is not something that would be either practical or safe for small scale producers - like a home brewer.

I am not familiar with camelina oil. Is it cheaper than soy, canola, rapeseed, or any of the other more commonly used feedstocks? If so, then the idea of blending in as much camelina as possible while still staying under the target IV number of 120 has some appeal for small scale producers.

 

What I am hearing is if you blend an oil with a hi IV number it will not change the fact that with O2 present you will form plastic particles. The particles will build up and plug the injectors, fuel filters and fuel lines.

Is that correct?

 

Willbd

You pretty much hit the nail on the head.

CheaperJeeper

It has to do with the reactivity of the molecules, the more double bonds in a molecule the more reactive it becomes. Once a peroxide forms it can react with any molecule, whether or not the second molecule has a double bond, if the second molecule has an ester bond. All Biodiesel molecules have ester bonds. Each molecule of BD, added to the original chain, increases the chain length by 12 to 16 carbons. Longer chains equal increased viscosity.

Blending oils to decrease the number of molecules with multiple double bonds will not decrease the reactivity of those molecules that do have multiple double bonds you must decrease the number of double bonds per molecule.

Like I said before it is easily done.

 

I don't fully agree with your polymer chemistry Phydeaux. Having multiple double bonds in a chain will make it more likely that the molecule in question will react, but each individual bond pair has an equal chance at reacting, even if there is ony one in a chain. The blending operation since it will reduce the total number of unsaturated sites will slow down the oxidation/polymerization process.

And yes, as you have pointed out, the entire problem can be reduced by hydrogenation.