Preventing Clouding/Gelling

[nichol Biofuels Forum Newbie Find all posts View Profile Close nichol]

Hi all. I am new here, I have only cottoned on to using Bio-Diesel in the last few months in my 1994 Land Rover Discovery. I doubt I will return to using normal diesel, the benefits of using the Bio are too good! I have been buying it from SAFF in Boronia, not game enough to make my own [yet] . Very informative forum you have here. And so for my first question:

Basically, whats the best way to prevent B100 from clouding/causing blockages over winter. I was thinking along the lines of kerosene 5-10%, I have prepared a few samples of different concentrations to chill down and observe. I'm also guessing normal diesel is fine but you would need LOTS more, up to 50-60% for effective dilution.

Any tips to prevent gelling would be great! Thanks

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

Re: Preventing Clouding/Gelling

Hi Nichol and welcome to the forum.
I find the simplest way to prevent gelling and blocked filters is to add a bit of dino diesel. The amount will depend on the bio and how cold it gets.

I don't think the quantity you need to add will change between dino diesel or Kero, as kero/Avtur is used as diesel fuel in some parts of the world. There are posts on this somewhere.

You are on the right track doing tests. This will give you the information you need.

[Guest Close David]

Re: Preventing Clouding/Gelling

I don't think the quantity you need to add will change between dino diesel or Kero,

I looked up the freezing point of kerosene and found it lists at -40 to -48oC.
Petrol was listed as freezing at -58 and boiling at 110oC (For all those thinking of heating their blend )

Diesel being a composition of many different ingredients and blends was a lot harder to find freezing points for. What I did find listed Diesels freezing point as around -12oC or Warmer. Some sites suggested gelling would occour at around the same freezing point as water.

Form this we can see that Kero and petrol would provide much greater protection against gelling and freezing of bio ( or veg) than diesel would both from a temprature standpoint as well as the quantity required.

Petrol would have an upper limit of 30% in fridgid conditions but 20-25% may be more workable. Kero is said to have a max dilution of 80% with veg oils because of the need for lubrication from the oil.

In any event, diesel may be ineffective as an antifreeze in very cold climates but kero and petrol would work in all but the coldest place's on earth and in Australian conditions would require much less to be mixed in than diesel would, if diesel were effective at all.

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

Re: Preventing Clouding/Gelling

David and others, diesel has a gel point of below approx -5/6 normally (in Qld summer don't ask as I found out the hard way) and down to what you quoted for alpine diesel (winter in the snowies). Bio mixed with Kero is a good option, only thing is that it is more expensive than petrol but less volatile than petrol.

Now as for Kero, it is called Diesel No1 in the USA and is used in the arctic and antarctic as fuel, neat. It is very close in all behaviour to diesel and will happily run in your engine, only problem is it has absolutely no lubrication at all, dry as the proverbial and causes wear in the engine. They don't have to maintain their diesel like it was their own in places like that, do they?

If it were me I would mix in diesel, its good to well below zero most of the year and if your south of the border (as most you mexicans are) then its even better in winter and the fuel companies adjust what is out there a few months in advance by adding some kero (& not much else I suspect).

Matt

[sean musso Donating Member Find all posts View Profile Close sean musso]

Re: Preventing Clouding/Gelling

Hi nichol ive just fitted a vegtherm heater and extra fuel pump on our new nissan navara to stop the fuel from gelling over the winter months this will pre warm the fuel as it reaches the fuel filter and circulate back to the tank and help warm the fuel there as well,the heater is claimed to heat the fuel up to 70 degrees as it goes through i dont know how true this is but after turning it on you could feel the fuel lines warming up within about 30 seconds this heater cost me about 250 dollars au Im hoping this will help us on the cold mornings in Ballarat check out Steve Hobbs Kaniva on0353922823 hope this can help you

[vegehilux Junior Member Find all posts View Profile Close vegehilux]

Re: Preventing Clouding/Gelling

G'day,

I have found that leaving the biodiesel in the wash tank for a couple of nights in cold weather will drop out a lot of waxy looking crystals into the wash water.

Then I dry the bio in a drum using heat (65-70C) and vigorous bubbling with an air compressor, until the air coming off the diesel does not fog my sunglasses or condense on the stainless tube I use for bubbling (see my other posts).

Then I add a product called "Fuel Set", which is a diesel additive sold a various auto accessory shops at the amount recommended on the bottle, and seal the drum and let it cool.

This has shown good results in sub tropical winters, can't speak for down south.

Using only cottonseed oil will also give better results than tallow, but you have to take what you can get.

Hope that helps.

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

Re: Preventing Clouding/Gelling

"Using only cottonseed oil will also give better results than tallow, but you have to take what you can get."

Quite correct. In general, the shorter the hydrocarbon chain the lower will be its gel point. Or, to put it another way, BD made from solids (tallow) will have a higher gel point than BD made from liquids (like cottonseed)

[KiwiGuy Biofuels Forum Newbie Find all posts View Profile Close KiwiGuy]

Re: Preventing Clouding/Gelling

What effect has mixing ethanol got then ?

Does it make the mixture more unstable or what ?

[Guest Close David]

Re: Preventing Clouding/Gelling

Hi nichol ive just fitted a vegtherm heater and extra fuel pump on our new nissan navara to stop the fuel from gelling over the winter months

Sean, The problem with this is at startup your IP and injectors will still be filled with cold oil and there is nothing you can do to heat it. The vegtherm will stop fats blocking the filters if you are not removing the fats in your prefiltering process, but any fats that are present will be giving your IP and injectors a hard time when you first turm the key in the morning.

If you are using bio or diesel, the vegtherm still won't help with starting but may help with the running of the vehicle.
I have just added a coolant type fuel heater to my car and am looking at adding a second loop to run the return fuel through to help warm what is in the tank and dislove any settled fats or waxes that may inadvertantly accumulate.
I would suggest that a measure of Kero or unleaded in your fuel may be worthwhile in giving you easier starts by thining the fuel when and where heat can't.

Kiwi Guy,
I have been blending my oil with an unleaded fuel that does contain an amount of Ethanol. I don't know the percentage of Ethanol, I suspect it is higher than what it probably should be, but it blends and stays blended just fine. In the tests I did, Methanol is dissicult if not impossible to blend with WVO and I could not get it to stay mixed without seperating.
Ethanol would not affect the stability of the oil and would only serve to thin it and give it higher restiance to clouding/ gelling, both desirable attributes.

The addition of Ethanol would lower the cloud/ gel point the same as petrol or Kero. I do not know what the max blend rate would be if you are going to use pure Ethanol but I would suggest 20% would be safe and effective.

[Gunner Donating Member Find all posts View Profile Close Gunner]

Re: Preventing Clouding/Gelling

Vegehilux is on the right track with Cold-filtering his BD.
The problem with blending kero or ULP with BD is that the gelpoint of the BD in the blend has not changed. If for example, you choose to blend your BD with 25% ULP, on a very cold night the 75% of your fuel that is BD will still suffer from gelling. You might find that the particular feedstock in your BD will result in more than half of that solidifying, resulting the liquid portion of your fuel being made up say 40% ULP and 60% thick BD. The presence of the ULP will reduce the viscosity of the thickened BD, but presents a danger in the operation of the engine.
If you expect the onset of cold weather (were getting to that part of the year now!), refridgerate your BD and cold filter the semi-solid parts in suspension. Save this residue for the warmer months, as it is perfectly good BD, it's just not suitable for freezing weather. Better yet, choose feedstock oils that already have a low melting point.

[hdj80 Senior Member Find all posts View Profile Close hdj80]

Re: Preventing Clouding/Gelling

I did some tests last year in Canberra and we can get down to -7DegC no prob's in winter.
I had a sample in a jar in the open and another sample in a same jar in the open but up under the rear fuel tank of my 80.
Well the one in the open was solid ice by morning at and the one under the 80 was thick and would block any filter. I did a rough estimate of a 5degC difference (rough). I didn't continue with experiementing to get exact temps as even though the jar was under the tank it was still subjected to surrounding cold air. So the fuel in the tank even though would have being cloudy probably would have been fine......It was just to give me an idea of the possible condition of the fuel in the cold..... Having said that, I did still continue to add some Dino diesel upto B50 in the subtank and B100 in the main and just switched between the 2.

[mrnamjama Junior Member Find all posts View Profile Close mrnamjama]

Re: Preventing Clouding/Gelling

hdj80, if you had only one tank, would you say that running B50 in the colder months in Canberra would be necessary?

[hdj80 Senior Member Find all posts View Profile Close hdj80]

Re: Preventing Clouding/Gelling

hdj80, if you had only one tank, would you say that running B50 in the colder months in Canberra would be necessary?

Yes however add a Fuel Heater and a pusher pump you could get away with B80