Oxidisation/Polymerisation on Cottonseed oil - photos

[hannahs bridge Donating Member Find all posts View Profile Close hannahs bridge]

Re: Oxidisation/Polymerisation on Cottonseed oil - photos

As I haven't had my tank coated can anyone point me in the direction of where I might be able to source some antioxidants / metal deactivators ?

Angus,
as the principal industry using antioxidants and metal deactivators is petro chemical manufacturers most suppliers sell a minimum quantity to treat in the vicinity of a million litres; keeping in mind that a little of this stuff goes a long way.
Of the few companies that I approached, only one seemed remotely interested in small users.
CIBA recommends IRGANOX L 57 as a suitable antioxidant for VO. A min. of 190 l @ .2%, by my maths., will treat a mere 95,000 l.
IRGAMET 39 (metal deactivator) min. of 20 kg. @ .05% treats 40,000 l.
If you are still keen to try some but feel that these quantities are a bit more than you need you can send me a message and I may be able to organise a smaller quantity.

The above conditions (except the ulp) met the criteria for polymerisation to occur, but as yet absolutely nothing has happened. Any suggestions?

Michael,
Nice work. As I understand it polymerisation produces, among other things, polymers. If nothing else is produced in the reaction then there will be no visible contaminents. To test for the presence of polymers the only two methods that I am aware of are odour and a Peroxide test. As dictated by Beatty.

Malcolm.

[BrianW Senior Member Find all posts View Profile Close BrianW]

Re: Oxidisation/Polymerisation on Cottonseed oil - photos

There is so much information appearing on the subject, which is great and I thank all contributors. Special thanks for providing some details and names of some anti-oxidants as this is something I wish to pursue.

The formation of the ???? only occurred inside my tank fitted to the vehicle ,but when it was stored in the 20L oil drums nothing was produced. I recently emptied a drum that I thought had all the right ingredients except exposed steel which had been sitting for quite some time and there was nothing there either.

If I was unable to reproduce the production, then I will count myself lucky.

regards

Brian

[bruceT Senior Member Find all posts View Profile Close bruceT]

Re: Oxidisation/Polymerisation on Cottonseed oil - photos

The formation of the ???? only occurred inside my tank fitted to the vehicle ,but when it was stored in the 20L oil drums nothing was produced.

BrianW, Any clues amongst these recommendations from Joe Beatty?

Recommendations
1. Do not allow Copper to come in contact with WVO. This
is not revolutionary, many references in the literature site
less than 5 parts per billion as the only safe level for
copper in vegetable oil.
2. Coat your steel tank.
3. Don’t insulate your Veg fuel tank unless absolutely
necessary for you local climatic conditions. Heated oil
says hot long after the engine is turned off.
4. If a heated fuel pickup is sufficient, use this rather than a
heating coil. Keep in mind heat is number 2 on the list of
contributors to auto-oxidation.
5. Loop your return. This serves two functions, heat from
the remainder of the fuel system is not returned to the tank
and secondly, any metallic ions scavenged in the fuel
delivery system are not returned to the tank.
6. Don’t use diesel fuel additives. One study finds that a
dimer acid corrosion inhibitor found in virtually all diesel
fuel additives and some diesel fuels greatly destabilizes
vegetable oils in concentrations as low as 20 ppm. (3)
7. Do use an antioxidant/ metal deactivator. In
conversations with three different commercial antioxidant
manufacturers, all made the same, admittedly selfserving,
statement that they would not consider the use of
vegetable oil as fuel without antioxidant protection. This
due to the fact that vegetable oils are, on average, 85%
unsaturated and therefore very susceptible to oxidation.

[angus@aroundyoga.com Member Find all posts View Profile Close angus@aroundyoga.com]

Re: Oxidisation/Polymerisation on Cottonseed oil - photos

Malcolm,

Yes I would like to see if I can get some, the other alternative would be to try the people who actually produce the vegetable oil, as they add antioxidants, I have a friend in the food industry I will ask,

Angus

[BrianW Senior Member Find all posts View Profile Close BrianW]

Re: Oxidisation/Polymerisation on Cottonseed oil - photos

BrianW, Any clues amongst these recommendations from Joe Beatty?

Without a source for antioxidants I decided from that my only real option was to coat the inside of the tank to remove the steel from the equation. This made sense since it was already clean and cut open. I used yellow paint so that if it starts to lift I will see it collecting inside my filter.

The 20L drums for the veg oil are all zinc or nickel coated inside and out and were no problem.

So far all is going well.

[bruceT Senior Member Find all posts View Profile Close bruceT]

Re: Oxidisation/Polymerisation on Cottonseed oil - photos

The 20L drums for the veg oil are all zinc or nickel coated inside and out and were no problem.

Zinc = BAD Just ask Tony...

Brian, what sort of paint did you use? I presume it wasn't and "oil based paint"

[Alga Senior Member Find all posts View Profile Close Alga]

Re: Oxidisation/Polymerisation on Cottonseed oil - photos

Joe Beatty says not to let copper come in contact with WVO, so what about the copper in H.E's. I'm trying to decide whether to put my tank changeover for both cars, before or after the HE. If I put it after, then the oil in the H.E. will heat up quicker so I can change over faster and not heat up the BD or Diesel. But will having the oil sit in the H.E. Overnight or a day or two, cause polymerisation or oxidisation in the H.E. with the temp changes. If I put it before, then I'll have a large amount of Bd or diesel flowing through the system and getting unnecessarily heated, whilst the oil just sits in the fuel line cold, which to me is a waste. How long can you have WVO sitting in copper before it has an effect if any.

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: Oxidisation/Polymerisation on Cottonseed oil - photos

Alga,
I do not have a difinitive answer for you but I have a copper heat exchanger on my Fatmobile, an '84 MB 300D. It heats up the oil before the veggie filter and whichever fuel is selected, after the c/o valve, immediately before the IP.
The veggie and biodiesel are incontact with the copper for weeks on end, during the times I am using my other 300D (Elisabeth).

I have a FPHE in Elisabeth just before the IP, HOH and a heated CAV filter for the veggie. There are brass fittings on the FPHE and it is constructed using copper brazing, but only a minute amount of copper would be in contact with the fuel. I believe that there would be more copper contacting the fuel in the brass fittings, than contacting the fuel in the FPHE.

I have not had any issues with polymerisation of fuel in either vehicle.

[Alga Senior Member Find all posts View Profile Close Alga]

Re: Oxidisation/Polymerisation on Cottonseed oil - photos

Thanks Tony, as I have a FPHE you sent me to put into the land cruiser and it doesn't have a return line to the fuel tank, I will put the changeover after the HE. I intend using diesel to start in the winters as starting on oil blend is very hard, whilst I have some gel problems with bio that I wish to sort out first. My triton ute stars ok on oil blend no matter how cold, but does display some bad running until warm and I put that down to cold oil and it's high ignition point, very smoky and misfiring. When I put the big tank in I will start her on bio if I get the gel bit sorted.

[BrianW Senior Member Find all posts View Profile Close BrianW]

Re: Oxidisation/Polymerisation on Cottonseed oil - photos

How long can you have WVO sitting in copper before it has an effect if any.

I think you are pretty safe with the heat exchanger. In my tank the polymerisation only occurred to the top of the tank where the steel, oil and air were available. There was basically no indication of anything on the bottom except for a couple of spots, which I attribute to when we ran the tank dry and did not fill it up for some period of time. Compare this to the 7L of the stuff attached to the top and sides of the tank.

I have decided that since I am using a steel gear pump, that I will always turn off the pump with oil in the lines so that there is no air trapped there.

Another good reason to feel comfortable with the heat exchanger is that the occurrence of the polymerisation seems quite rare.