Coffee in the fuel filter..Pt 2

[dgs]

Hi dgs, yes 400ml to 200ltr, that is ? 0.05% ??
If you were to use it as a stop bath, "for the want of a better description" how little would you be using per 200ltrs

What about washing, spin the motor to kick start or just mist wash,

Dave

still have a photograph to put up here for Tony

For the colour comparison test i used 15mls of 50% acetic in one wash and 10mls in the next, for a 200 litre batch. You are using 400mls of 97%, still can't get my head around that.

If you use the 5% prewash method or similar the soap is so low after you have removed all the wet glycerol you can wash as aggressively as you want and there is no risk of a soap emulsion, you don't need to use acid.

I'm wondering if your massive over-addition of acid is something to do with the coffee granules.

[Tony]

Remember journeytoforever?  They mention acid wash, but phosphoric, 2-3ml per litre.
http://journeytoforever.org/biodiesel_aleksnew.html

"NOTE: A deposit may form in the bottom during settling -- don't let it get in your fuel tank!"

Hmm.

[dgs]

I do remember it Tony, they mentioned a lot of stuff, a lot of which was a total load of nonsense. Just looked at your link again, Doesn't even mention bubbling with heat to dry it, just settling. I know it is an old site and things have moved on but .............

[countrypaul]

I don't think food grade acetic acid is always the same as glacial acetic acid, in many, not all,  cases it is already diluted to a degree.

Glacial Acetic acid is about 62g/mole so at 1.05 density would be around 62ml/mole so 400ml would be around 6.5 moles. That means there would be enough acid to neutralise 260g of NaOH.

If you are looking at soap with a mw of around 300 there would be enough to convert 2KG of soap back to FFA!  Looking at it another way that is over 1% of your bio as soap ie. over 10,000ppm

The coffee granules are quite possibly oxidised bio. I left a sieve covered in bio for awhile (not sure how long buts weeks cerainly) and when I came to reuse, it was covered in dark brown residue.  Commercially I believe they add vitamin E to bio in order to inhibit the oxidation process.

[Tony]

Commercially I believe they add vitamin E to bio in order to inhibit the oxidation process.

Interesting.  A google around vitamin E brought this study up: https://www.biodieselbr.com/pdf/estudo_aditivos.pdf
It suggests Bioextend and Ethanox are effective for stability but I can't find anywhere to buy either here.  The study does say that commerical antioxidents "include butylated hydroxytoluene (BHT), butylated hydroxyanisol (BHA), tertiarybutylhydroquinone (TBHQ) and propyl gallate (PG)"

The former is also used to treat genital herpes apparently.  Not something I'm going into the chemist to ask about anytime soon!

[WesleyB]

I've thought of something that might be an answer to the dark material composition . In used vegetable oil there are small particles of food . Might look like brownish sand suspended in the used oil .  These small particles of food may act as a sort of seed crystals pulling glycerol into it . As best I understand based upon the description , the brown material occurs in fairly new biodiesel . An auto-oxidation product is slow to form .

[WesleyB]

Canidrive wrote if I understand 400-200 ml food grade acetic acid , then 0.05% .   5% acetic acid is white vinegar , not glacial acetic acid . I reacted vinegar with potassium soap at elevated temperature .  it made potassium acetate (water soluble) and free fatty acids (not water soluble ).

[Tony]

This is the inside of my spare IP, admittedly after sitting in air for about a year but even so...

[WesleyB]

I believe what that is , is autooxidation of biodiesel . In short , two biodiesel molecules bond to each other through one oxygen atom , at the location on the fatty acid chain of a double bond .  So the molecular weight about doubles and solubility properties change .  There are descriptions of autooxidation of biodiesel on the internet .  I'm not sure of a workable solution for that problem other than cleaning the fuel system and changing fuel filters .  The reaction is a free radical reaction . There are chemicals that hinder free radical reactions with some degree of effectiveness . I think beta-carotene might have been one of them .

[Julian]

This is the inside of my spare IP, admittedly after sitting in air for about a year but even so...

Ha, call that coffee grounds?

THIS is coffee grounds ...



and this is what it looked like after cleaning ...



It's the heated chamber on top of my fuel filter and that's something like 8 years accumulation.

If beta-carotene is the answer, I'm off to buy a sack of carrots and a blender.

[Tony]

Nice!  Can't see how that does any injection system any favours.

[dgs]

Julian, what happened to your oxidation test sample, the one with the piece of steel in it, if you still have it are there any coffee grounds in it.

[WesleyB]

There used to be carburator cleaner that was available in a spray can here in Texas . I believe part of the cleaning liquid was ether . It was used by running the engine a little faster then spraying the liquid into the air intake of the carburator . It dissolved the crud build up and left a cleaner fuel intake system . I don't know if ether is easy to get in the UK . I'm wondering if the coffee grounds are soluble in ether . Although ether will dissolve many types of plastic and rubber , there might be a way to clean biodiesel powered fuel systems easier using ether as an additive in the fuel .

[Julian]

Julian, what happened to your oxidation test sample, the one with the piece of steel in it, if you still have it are there any coffee grounds in it.

Pretty good memory, Dave.  I'd forgotten all about it!

It sat for many months and went thick and gooey, just as very old veg. oil does.  Certainly didn't look anything like brown stuff above.

[CanidrivE]

Hi guys, nice to see more coffee type stuff, SO how do I put a photograph on here ?

I have an idea

Dave

Think I may have found the photograph placement place ?