My first wash. AARGGHH

[Bueff Biofuel Enthusiast Find all posts View Profile Close Bueff]

Re: My first wash. AARGGHH

Thanks Tilly that's good to know. I will try that on the next batch.

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

Re: My first wash. AARGGHH

PS, I just noticed that Neutrals yields followed very closely Neutral's "rule of thumb" that says soap will take about twice it's volume of biodiesel into the waste/ glycerin.
In neutral's above experiment he had 5% FFA which equates to 5% soap production.
His yield was 84.4% which means there was an additional loss of 10.6% biodiesel. That is pretty close to twice the amount of soap

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

Re: My first wash. AARGGHH

UPDATE:

things didnt quite go to plan.

I think I realised what I did wrong. I neglected to tap off the water that would have been sitting in the bottom before I started heating the brew up.

First thing I did was remove the existing thermostat from the circuit, so the heater had a free run. turns out it is a 3600 watt element, not a 4800W.

turned it on and kept an eye on it. took about 3 hours to go from 22 degrees to 80 degrees.

from the moment I turned it on, the heater was creating what looked like soap bits which floated to the surface and stayed there. all teh way up to 80 degrees it looked like orange juice.

well I stuck my head in when it got to about 80 degrees and it was basically boiling. a very energetic convective current was driving a heck of a lot of turbulence. the fuel was basically clear(er) but I could see a lot of something else lighter and thicker bubbling up and rapidly sinking.

so I smiled to myself and turned off the heater to stop the convection current, with the intent of tapping off the water and continuing the heat process as mentioned by Tilly Et Al..

so the first bit was defeintly water, very thin and splashy, creamy colour. I thought "wow this is awesome". but then came a lot of what I thought was a soap layer. it diodnt really stop coming. after I tapped off 40 litres of water and what I thoguht was soap, i realised something was very wrong. my yield would be atrocious at this rate. the soap layer was actually an emulsion.

now its a big AAAARRRRGGGGHHHH

I dont know how much is emulsified in there. So i got some vinegar from the hugs and kisses and spray that ontop of the 20L bucket, and it broke quite well.

question 1:

What do i do?

a) keep tapping off the emulsion and treat it outside of the brewer
b) attempt to break the emulsion that remains in the brewer
c) keep heating it now the water has been removed (apart from whats in the emulsion) and see what happens
d) something else I havent thought of.

what happens to the vinegar? does it settle into the bottom of the drop out or does it stay suspended in the fuel?

I checked my little sample jar that I clarified on the stove last week for water content - it passed. very happy with that at least. I am using the shell aviation water / fuel test devices.

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

Re: My first wash. AARGGHH

Ok so I did a search on the topic and learnt that there are a few ways to crack it. I might try heating it again and see what happens.

not very keen on vinegar and salt, unless its saturday afternoon down at the beach.

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

Re: My first wash. AARGGHH

Hi Cade,

I think you have answered your own question.
I would just let it sit and see if the emulsion breaks on it's own, then remove water and continue to heat. Otherwise you know vinegar breaks the emulsion.
Vinegar is mostly water with about 5% acetic acid so I would not worry about it. You might give it a quick wash if you are worried.
The acetic acid in the vinegar converts the soap back into FFA's and that is the reason the emulsion breaks.

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

Re: My first wash. AARGGHH

Thanks Tilly.

is there an approximate ratio / proportion of vinegar to brew that I should be using?

I am over waiting. this brew has been 3 weeks in the making so far. I need to be able to brew 200 L and wash in 1 to 2 days max.

question about 'drying'. So after I heated that little sample on the stove the other night (no bubbling) and stored it back in a sealed glass jar, I checked the water content using my little aviation fuel testers. it passed with absolutely no indication of water at all.

now I dont know what the trigger PPM is on the indicator, but seeing that this is the last test for water before the fuel is used in multi million dollar engines, i am tipping that the test is extremely sensitive to water.

so - if simply heating the washed fuel to remove water is sufficient, why do people bubble after wards? its not meant as a snide remark at all, as I am yet to even successfully wash my first batch, I am just interested to see what peoples motivations are, and how they believe the process is improved by bubbling. I am sure if you didnt heat the batch you would probably need to bubble though.

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

Re: My first wash. AARGGHH

Hi Cade,

is there an approximate ratio / proportion of vinegar to brew that I should be using?

I can not recall that I have ever used an acid to break an emulsion.
My thoughts are that you should use as little as possible that will do the job you are after.

question about 'drying'. So after I heated that little sample on the stove the other night (no bubbling) and stored it back in a sealed glass jar, I checked the water content using my little aviation fuel testers. it passed with absolutely no indication of water at all.
now I dont know what the trigger PPM is on the indicator, but seeing that this is the last test for water before the fuel is used in multi million dollar engines, i am tipping that the test is extremely sensitive to water.

{Quick Edit}It seems that the Shell Aviation Water Detector detects Free Water from about 10ppm and above.
The Australian standard for water which also happens to be the ASTM standard is free water must be under 50ppm.
If you see no change in the Test that suggests your water is well below 50ppm
http://catalog.beckerandassociates.c...water-detector

so - if simply heating the washed fuel to remove water is sufficient, why do people bubble after wards? its not meant as a snide remark at all, as I am yet to even successfully wash my first batch, I am just interested to see what peoples motivations are, and how they believe the process is improved by bubbling. I am sure if you didnt heat the batch you would probably need to bubble though.

There is a lot of "by Guess and by Golly" that goes on with biodiesel production.
A lot of well meaning people who do not know what they are talking about post inaccurate information.
A few people knowingly post inaccurate information and I have never been able to figure out why.

I have never heated to dry biodiesel when making biodiesel to fuel my vehicles. For a few years I did use an aquarium pump to dry biodiesel but now I just leave it sit for months or years.
I would imagine that if you are trying to increase the speed you dry your biodiesel, bubbling while heating would help, however you might need to be using a large quantity of DRY air to make any real difference.

[Chev28 Senior Member Find all posts View Profile Close Chev28]

Re: My first wash. AARGGHH

The bubbling is done at the same time as warming and simply speeds the drying along.

I never needed much heat when bubbling at the same time. Only about 30 degrees or so.

I am no expert or chemist - just saying what worked for me.

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

Re: My first wash. AARGGHH

Thanks for your time looking up the water detector. thats good news, so if it passes the test (i.e. less than 40 PPM), then it is definitely dry enough to use (less than 50 PPM as per ASTM).

That was my major concern in washing - was achieving dry fuel. I am glad I have the means to achieve it and test for it.

Thanks Chev, I will see how fixing this brew up goes and then consider bubbling. I might try and hook up a 12v battery or something to bubble with as I generally turn my shed off when I am not in it.

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

Re: My first wash. AARGGHH

Cade a few years ago when I studiously dried my oil while up settling I found that some solar heat helped a lot. A 200 litre drum of oil which failed the hot pan test could be dried in one day with a small aquarium bubbler running for a bare 6 hours while the oil was warm (30 -40deg). BTW the bubbler while running 12volts was actually an AC device which used a small transformer to convert 240VAC to 12VAC so it won't work with a battery. It is however a very low power device and can dry 200 litres at a time with a little wall wart not a lot different to a phone charger.
These days I don't dry my oil as it dries itself by settling, helped by care not to add the dregs of containers which may have free water on the bottom.

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

Re: My first wash. AARGGHH

Acetic acid is a stronger acid than free fatty acids. The sodium or potassium salt of free fatty acids (soaps) switch the sodium or potassium to acetic acid giving sodium acetate salt and the free fatty acid resulting

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

Re: My first wash. AARGGHH

Hey Wesley,

unfortunately it looks like your post was cut off. would you mind please continuing?

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

Re: My first wash. AARGGHH

UPDATE:

so last night I did a bit more cooking on the stove. took some mayo and heated it. man o man that makes for some trippy viewing. best damn lava lamp i have ever seen.

anyway heating certainly assisted, but I found I needed to heat and apply a small amount of vinegar to break it properly.

as per previous, when it cooled it was cloudy. so I took the fuel off the top (leaving remains behind) and heated again to just under 100 degrees.

this time there was no real drop out at all, no vapour, no boiling, just bloody hot fuel.

and it stayed clear and bright after cooling. I checked for water content, and it passed.

My new heat controller setup should rock up this week, so i will install it and try it out.

on the topic of vinegar qty, I found about 2 tablespoons was sufficient to break the brew of about 500ml. I didnt try less and slowly increase, I just dumped it in.

on that basis, it would need about 12 litres. that sounds pretty extreme. I think I will muck about with some samples a bit more tonight and see how much it really needs.

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

Re: My first wash. AARGGHH

I was interrupted while typing a reply. To continue, I made potassium or sodium soap from sodium or potassium hydroxide, on purpose. So I made normal soap. I put maybe 1/4 gram of the known soap into a 50 milliliter beaker, added some vinegar, heated with a Zippo cigarette lighter and got a bouyant transparent liquid floating on the surface (liquid free fatty acids). In chemistry there is continuity of elements (mass), things just don't dissappear, except in nuclear. Soap is a free fatty acid, a long carbon chain with a carboxylic acid group on the end but there is an atom of the metal sodium or potassium bonded to an oxygen at the end of the chain (14-22 carbons in length) . The shorter carbon chain acetic acid is a two carbon atom chain molecule and a stronger acid, I'm not sure why it's a stronger acid but it is. If there is an electronegativity difference of greater than 1.5 (I think it was) then in the presence of some water the atoms can seperate and switch so the sodium or potassium of a soap bond to acetic acid (vinegar) and the hydrogen of the carboxylic acid , vinegar transferers to the soap which becomes a free fatty acid. When I water washed small quantities of biodiesel, once I got the purified stuff distilled water poured right through it. I've never seen the orange juice referred to here. If salt was used to break the emulsion, most of it should be removed by washing before burning the fuel. Breaking the emulsion with vinegar puts a little high boiling free fatty acids into the product biodiesel, which is not good.

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

Re: My first wash. AARGGHH

Hi Wesley,

I've never seen the orange juice referred to here.

Just washed biodiesel with lots of water still in suspension looks like "Orange Juice". You do have to agitate to thoroughtly mix the biodiesel and water.