Biopowered - vegetable oil and biodiesel forum
Biodiesel => Chemistry and process => Topic started by: CanidrivE on September 04, 2020, 10:53:24 AM
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Hi all, got feed-up being of reading error, Bandwidth used up or what ever" so I signed up to here yesterday.
Without having to post any thing over from the other thread and to the likes of county paul, dgs, redsailor and all who else replied, the last batch I done was without my usual acid stop wash
The one thing I did notice was the color change, I have a photograph taken and the link should be down below (hopefully working from face-book)
Left flask is fuel UN-washed from top of reactor
Middle flask is after water 3 wash wash from top of reactor
Right flask is from my storage tank
Dave
https://scontent.fman2-2.fna.fbcdn.net/v/t1.0-9/118869771_3808234272524920_4591975884725480745_o.jpg?_nc_cat=111&_nc_sid=8024bb&_nc_ohc=Yesn77sc5jIAX-q_BqJ&_nc_ht=scontent.fman2-2.fna&oh=d6cb260ee29110c65ea44ab09407dd2e&oe=5F75B2E9
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So the lighter one on the right is from previous batches that have been acid washed?
When you say coffee I assume you mean the runny (well, slow runny) looking brown stuff that's like very light glycerol (which is what I think it is!)
I used to get that to an extent, but all my batches are just settled, rather than washed, so I think it's trace glycerol left over or perhaps a tiny ongoing reaction. I leave my batches extra long to settle now and that seems to help.
I've seen batches that are darker in colour (like your left ones) sometimes take a very long time to drop the last bits of glycerol out. Like it's somehow better suspended in the fuel.
I don't do the water shake test for soap any more, I've come to recognise how quickly the foam settles after being violently pumped through a 1u filter. If bubbles remain on the top and don't quickly pop, it's still soapy...
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Hi Tony
The stuff stuck in the fuel filters looks like coffee granules, not runny.
As for the color, since I acid washed "food grade acid" I have always had light coloured end fuel..
Here is one for you "all" to check, I pour my fuel into the car with a 1 inch or more size pipe jammed over the funnel and into the tank filler neck, just where the filler cap sits and deeper down, when I wipe it I get a to quote Tony here "the runny (well, slow runny) looking brown stuff that's like very light glycerol" any one else ever looked just inside the filler cap ?
So the link worked to the photograph
Here is how I done it.
first have a face-book account
upload a photograph
click on the photograph
when loaded, right click on the photograph
select Copy link location
and then paste in here
Dave
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Just checked my filler pipe with a bit of rolled up kitchen roll (nearly lost it into the tank!) and it's all clean.
My filling regime is slightly different. The fuel settles in 120l drums, then I pump out into 25l drums through a 1u filter. These 25l drums sit outside for at least a week in the sunshine before being put in the car. Another difference here, I use the "guerrilla refuel" method (pressure started syphon) so the drums remain upright and I am careful not to disturb them when lifting. I always leave a couple of litres undisturbed at the bottom of the drums, which gets poured back into the youngest settling 120l batch. Sometimes this includes a little trace of the runny coffee stuff that otherwise would have ended up in the tank if I'd just tipped the drum to pour it, so I shake the 2l up in the 25l drums to suspend it before pouring back into a settling batch.
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Hi CanidrivE, I did a test some time ago to see if acid washed/ treated bio was darker than non acid treated and my test proved that yes, it was darker. If you have ever produced bio by the acid esterification process using sulphuric acid it produces very dark bio.
http://biopowered.co.uk/forum/index.php?topic=2906.0 This is a link to the post, sorry but the pictures are a no no.
Is the lighter right hand sample in the photo from the same batch.
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Unfamiliar with acid in bio as anything other than an emulsion breaker. What's an acid wash & why do you do it?
TIA.
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http://biopowered.co.uk/wiki/Water_washing_titrated_acid_method (http://biopowered.co.uk/wiki/Water_washing_titrated_acid_method)
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Thanks for that, I had seen it & remain confused.
I use a single processor for making, washing & drying Bio & have never used acid except for a couple of times over 7 or 8 years when I've made an emulsion.
Am I missing out?
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Even though I did the acid/no acid experiment to see the colour change I have never been keen on using acid (other than breaking a mono emulsion in washed bio showing a soap level of @ 200ppm.)
Trouble with acid is that it hydrolyses the soap into free fatty acids. If the titrated method is used and the soap is high (probably several thousand ppm) then that amount of ffa's being returned into the bio can't be good, I'm sure it doesn't burn as well in our motors.
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Have a look at the photo on page 11 (and 14+) of this report:
https://www.mdpi.com/1996-1073/12/10/1953/pdf
That shows a familiar looking brown goo in a filter and also CP1 high pressure pump.
This is with biodiesel blends, however, to ASTM D6751 standard. It's interesting because the ASTM standard does set a tight limit on free glyercine, so there may be more going on in terms of reaction between biodiesel and mineral diesel instead.
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Hi all.
Tony I will put a photograph of my storage tank on here for you, mine tank does not move and it has a 1u filter on it.
gds, Dave.. my fuel is lighter in color than the stuff with no acid stop bath..
neisel, I do a 2 stag process, BUT, I only make one 33 - 35 ltr of methamix using NaOH .. stage 2 of my work flow is after stag one has been drained of glyce the final 10lts is added to finish off the batch, I run the pump for about an hour, and drain out the glyce over a period of at least one day, keeping this to clean the start of the next batch. THEN, add 400ml of food grade acid (if diluted 16 / 1 you have chip shop vinegar) + 20ltrs of water with the pump running to give it a good violent mix. The thinking behind this many years ago was with HC II and myself sitting in a cafe having a chat, was that the acid stopped any more reaction and then would be washed out with a long mist wash with no emulsion being made in the final wash stage.
The batch that I started last Thursday, I am still dropping out glyce, let me explain.
Got the oil on Thursday, put it into the reactor turned it on to bring up to working temp 55 deg C "give or take" turn on motor and add glyce from stage 2 of last batch.
Run for about 1/2 hour. stop drain pipe and after 2 hours drain off glyce, by this time it was 10pm
Friday 9am. Drain glyce, turn on heater, make methamix
10am it is at full working temperature, open valves turn on pump and add about 25ltrs of methamix
11am, turn off pump
12 noon, drain off glyce, turn on pump and add final 10ltrs of methamix
1 pm. turn off pump. drain pipes. Go away for rest of day.
9 pm drain off glyce
Saturday. 10am or there about, drain glyce only 1 - 2 ltrs
Sunday. as above, but mostly red "ish" looking fuel, not black glyce
Monday. leave it.
Tuesday (tomorrow) drain glyce if any in it, At a guess, I would say from knowing the past it will be red "ish" looking fuel which will give me a total of about 18ltrs of glyce for the next batch.
Wednesday will be wash day
I will not be adding acid, SO ! do I spin the pump and give it a good violent start to wash using 20ltrs of water or just start mist washing??
Dave
Photograph to be added here of storage tank
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Tony got a very quick read of that report page 12, I pulled my injectors out of my old Frontera, "failed wiring loom was cause of death at 230k - 130k on B100" got them tested and found to be working near perfect according to the test guys and believe you me, they are keen to get money off people, if the stuff ain't good they will say it.
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Wow, that's good news for people that make bio properly and burn it without blending!
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Hi CanidrivE, you mentioned in your post 400mls of food grade acid. From what you say this is glacial acetic acid. 400mls is an enormous amount to add, do you really add this or have you made a mistake.
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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
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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.
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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.
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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 .............
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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.
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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!
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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 .
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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 ).
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This is the inside of my spare IP, admittedly after sitting in air for about a year but even so...
(https://i.ibb.co/Ws6pnVs/ip.jpg)
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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 .
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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 ...
(http://www.palmergroup.co.uk/Bio/Coffee grounds.jpg)
and this is what it looked like after cleaning ...
(http://www.palmergroup.co.uk/Bio/Coffe grounds cleaned.jpg)
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.
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Nice! Can't see how that does any injection system any favours.
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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.
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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 .
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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.
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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 ?