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My vegoil cleaning procedure and experiance using baking soda in the wash water.
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UPDATE EDIT - 7-29-12 - My filtering procedure has evolved over time so some of the early posts in this discussion may no longer apply directly. I still use the basic filtering setup with the addition of water-washing the oil during the settling period as this extends the filter use by 4-5 times but my de-watering method has changed a few times. I no longer use the Flash Evaporator due to the additional maintenance and electricity costs. I now use an evaporation method by squirting the oil from the last filter back down into the center of the warm oil in the barrel such that it draws in a good bit of air along with the oil, this air gets heated by the oil, picks up water, rises to the top of the oil as bubbles which break on the surface and release the water as warm vapor, the vapor rises up out of the top of the barrel. The various changes are explained in the discussion as I made them. -- Tim.
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I have had a few Private messages asking for my oil cleaning process so here is my procedure.

Oil cleaning steps.

1 - Water washing --I used to do an initial screen/filter of the collected oil coming out of cubees or my vacuum collection tank, this was messy and realy did not save time as I still had to clean the barrels once settling was finished anyway. I now only dump the oil through some windowscreen wire to catch the chunks that are big enough to jamb up the gears in the converted chrysler engine lube oil pump that I use to move oil around.

2 - Before adding any oil to a clean barrel I pour in one cubee of clean water that has one pound of baking soda dissolved into it. I then fill the open topped barrel with oil to about 4 inches below the top. I then use a paint stirrer powered by an electric drill motor to stir this into a nice creamy peanutbutter looking emulsion.

Skimming and Settling -- The BS does cause a reaction while neutrilizing any acid in the oil (at least that is what I think and hope it is duing, it sure does make bubbles)(how do you definitively test for the acid content of clean waterfree oil ? (--UPDATE 5-05-07 -- The biodiesel TITRATION test will give a relative number based on the amount of water soluable acid and also the amount of free fatty acids in the fluid oil being tested), this acid neutrilization is exactly what I want it to do, unfortunatly, the acid neutralizing reaction produces carbon dioxide gas (CO2), this makes bubbles that rise to the top of the oil, these bubbles keep everything stirred up until all the acid is neutralized. This can take from 7-10 days from what I am seeing so far. As the bubbles rise they carry food bits with them, this creates a thick layer of "dough" for lack of a better discription, sounds better than "skum". I skim this 1-2 inch thick layer off the top of the oil every 2-4 days (UPDATE 5-05-07 -- I no longer skin this foam, it will mostly settle to the bottom of the barrel during the 7-day settling period). Once the bubbling stops it will take at least another week for the oil to clear by settling, more time is even better and will save on clogging filters.
Because of this extra time I am now using 4 settling barrels rather than 2 so I have a barrel of oil ready to filter every 3-4 days, not a problem after the first extra weeks pass.

Baking soda and emulsions -- Originaly I did not use the baking soda, I never had a problem with the oil and water not starting to seperate in the first day, this has not been the case since using the BS.

---UPDATE - 5-05-07 -- The following paragraph was confusing about the time I allow for the BS process to stop making bubbles, and about emulsion detection time, I have changed it to better clarify these points, I hope.. ---

If the oil has a lot of food bits, flour, batter bits etc, it has, so far, always seperated, but, if the oil looks fairly clean the oil/water MAY NOT want to seperate, especialy in this warm weather. (UPDATE - this seems to be caused by excess FFA's in what looks like clean oil, FFA's are sections of fatty acids that fryer heat or whatever has cleaved-off from the glycerins, since they are now smaller than the entire molecule they are also lighter, being lighter they will float to the top of the container after some period of time, they actually seem to make warm oil thinner so it looks like very good oil, when, in actuality, it is high in FFA's. the BS turns these FFA's to soap, this excess soap, being a surfectant, can cause emulsions to form).

I have tried several things to get the seperation of an oil/water emulsion started, it took several weeks this spring to figure out something that has, so far, caused seperation to start every time I have done it. (UPDATE 5-05-07 -- This is still working to start seperation)

After stirring the oil/BS-water together, I wait for 7 days, during this time the BS reaction will cause CO2 bubbles to rise, these bubbles keep everything stirred up and will likely create a 3-4 inch layer of froth on top the oil, I originally skimmed this froth but now don't bother till the end of the 2 week washing/settling period, most of the froth drops to the bottom of the barrel once the bubbling stops. Once the bubbling stops I watch for the water/oil to start to seperate, should see a layer of clean oil appear over the peanutbutter colored mix a day or so after the bubbling stops. If this seperation has not started by the second or third day after the bubbling stops I stir in 4 cups of plain old dry kitchen all-purpose flour. This starts absorbing water and the seperation should be under way by the next day, 7 more days for everything to settle and you have very clean oil.

3 - Once the oil has settled and looks very clean I pump this clean looking oil out of the settling barrel into my filtering barrel setup. I suck the settled oil off from the top of the settling barrel until I hit the layer of water/ pancake batter that has settled to the bottom of the barrel. (I had been pumping the bottom crud into cubees for the land fill but I will now be pumping all this into a seperate settling barrel for further settling to recover the last bit of oil, once this barrel is full of water/batter I will then fill cubees for disposal. I am also researching methane digesters to use this water/batter as feedstock ?)
UPDATE -- 5-05-07 -- Washing with water-only will give you 4 distinct layers in the barrel, clean oil on top, a "pancake batter" layer of stuff under the oil, then almost clean water below that. On the very bottom there will likely be a 1/2 inch thick layer of "SNOT", don't know what this is but it is VERY thick an stick. -- With BAKING SODA added you get 2 distinct layers, clean oil on top, then a single layer below that. The lower layer has peanutbutter colored pancake batter and soap at it's very top but as you progress downward it gets funkier, you end up with a nasty, septic tank smelling, blue-black, curtled layer of watery stuff on the very bottom.

4 - Filtering -- This consists of a barrel, 4 whole-house plastic water filter housings, and a small 12 volt DC shurflo diaphragm pump, all mounted on a cart with wheels, The pump moves oil at about 1/2 G/M at any pressure up to its shutdown pressure of 120 pounds.

this setup circulates the barrel of oil through 4 water filter housings in a row, The filter elements are sealed on there ends with felt seals and an additional plastic insert goes down there center so they do not collapse under the possible 120 pounds pump pressure. There is a pressure cut-off switch that is set to shut the pump off when the filters reduce the flow enough, due to clogging, to cause the pump to produce 120 pounds pressure.
The pump turns off when the pressure reaches 120 pounds but the filters will still slowly filter oil through them so as the oil goes through the pressure drops, once the pressure drops to about 80 pounds the pump turns on and again runs the pressure back up to 120 pounds where it again turns off. This cycle continues until I finaly intervene and change the filter elements. Due to the water-washing I am able to filter over 500 gallons of oil on one set of filters (not counting the oil circulation in this, 500 gallons is the amount of totaly cleaned oil, amounts to 12-15 barrels of settled oil as there is loss in the settling process)

The first filter housing uses only a 1/4 inch thick layer of paper towels wrapped around the plastic center section from and old water filter element, this catches any chunks that end up in the filtering barrel. The next filter is a 10 micron element, the last two filter housings both have 5 micron filter elements in them. I use the small 12 volt DC Shurflo RV water pump to circulate the entire barrel of oil through these filters for 3-4 days continuously at a flow rate of about 1/2 G/M, this passes the oil through the filters 30 or more times and insures clean oil. Most filters only catch 50% of the crud that is bigger than there micron rating so 30 passes catches 50% the first time, 50% of 50% the second time etc, 30 passes gets pretty close to everything that is 5 microns or bigger, as the filters plug with stuff they actually filter out even smaller stuff than there original micron rating.

5 - Once the oil is filtered I draw it slowly out of the bottom of the filter barrel and through the flash evaporator unit to remove all the water. My current unit only dries 5 gallon of oil per hour so it takes a day to do this. The dry oil may get blended immediatly and go into my truck fuel tank -or- it gets stored in 5 gallon jerry cans for use in the near future -or- it goes into one of several larger tanks for use whenever. I also use this oil as additional heat for my house during the winter and will be adding a diesel generator eventually so it will end up being burnt someplace.

6 - I am experimenting with cooling 25 gallons of clean dry oil at a time in an old refrigerator set to 40 deg. f. This should cause the higher melt point oils (hydrigenated oil and animal fats) to turn solid and drop to the bottom of the tank after a few days. I will save the thin liquid oil from the top to use as blending oil during cooler weather, the solid oil will be used in the heated 100 gallon tank that I am adding to my truck for use on longer trips. This may turn out to be more of a hassle than it is worth but I will have learned something along the way.

the following picture is of my 2 heated and insulated settling barrels. I have just recently added the other two plain old unheated and uninsulated barrels..

UPDATE -- 3-30-07 -- I have changed my dewatering procedure recently (last fall,actually) due to having problems with plugging the FE filter and also gumming up the plumbing of the FE (entire FE discussion here). At the 350 degree single-pass dewatering heat there is a tendance for some of the vegoil to turn gummy or even plasticize, may be polimerization - vulcanization, don't know exactly but the gumming up is a nuisance. I have found that if the heat is lowered to around 225 deg this gumming up problem is eliminated but the oil needs to be circulated a few times through the unit for complete dewatering. I now draw the oil feeding the FE from the output of the last filter on my filter barrel setup, the filter barrel circulates the oil at 1/2 G/M for at least 48 hours continuous, usually more. I now also dewater continuously during this same filter circulation period, dewatering at about 5 G/H, so the 50 gallons of oil in the barrel has been through the filters about 30 times and has also been through the FE about 5 times, this insures clean dry oil at the end of the process and the filtering and dewatering are done unattended over the same time period.

This message has been edited. Last edited by: Tim c cook,

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Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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This is a picture of the filter cart.

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Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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This is a picture of my prototype flash evaporator setup. ( I already have the white hair, the beard, and the limp, now I just need to get the white lab coat and the wierd laugh)

This is a link to the entire flash evaporator discussion.

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Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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This is a picture showing about a 3/4 inch thick layer of foam. This was 5 days after the oil/water/BS was originally stirred together. I had already skimmed off one layer of foam on the 3rd day of settling.

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Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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This is a closer view of the second skimming, notice that the oil under the foam already looks pretty clean.

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Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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Baking Soda? Flour?

Well Tim you are one out of the box... well done.
Thanks, as always, for sharing...
 
Location: west of the black stump (sometimes) | Registered: September 04, 2004Reply With QuoteReport This Post



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Seems like allot of work? Wouldn't it be easier to with just settle with plain gravity, filter through socks, heat (dewater), and then polish filter as you pump into the car?

It sounds like your oil may be clean when you are done but, it sounds like allot of added cost, time, and labor.

The upshot I can see is with all that flour and baking soda if, you ever had a grease fire, you'd wind up with a one heck of huge piece of fried dough (Elephant ears, as we like to call them in the South). Just add some butter, sugar, and cinnamon. Razz


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Location: Englewood, Fl | Registered: February 26, 2003Reply With QuoteReport This Post
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How about adding salt or brine instead of flour to get the settling to occur.

Another thought..... I know thats scary.

How about doing your acid neutrilization later in the process. Like maybe mix it in as powder after your water washed oil is settled. Then with with water and junk removed, any gas that rises has no junk to pull up with it. Remaining B.Soda will get caught in a filtering stage?


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Location: North Tx | Registered: November 23, 2002Reply With QuoteReport This Post
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Ziptar -- If you can get by filtering through socks and one pass through a final filter you are a lucky fellow, I would plug up vehicle filters in a hundred miles doing that, tried it, got tired of getting stranded in the middle of an intersection in a pouring rainstorm changing filters, no thanks, not any more.

I also have sensed a bit of damage to my injection pump over the last couple years, the truck does not start on the very first compression stroke like it used to with petro diesel, it does start on the first compression stroke with a somewhat thicker blend, could be a lot of reasons but one could be that the IP has more clearance than it used to. This has happened over only the last couple of years so it has occured faster than I would attribute to normal wear, suspect it is a bit of acid damage. I would rather be safe than sorry. The added time and tiny bit of treasure makes me confident (and reduces my liability) when I pass oil on to others.

The emulsion does not happen with every barrel, so far it occures about every third barrel. The total cost of BS and the bit of flour breaks down to about 50 cents/barrel. I end up with about 37-40 gallons of clean oil from each barrel so the added cost is only abiut 1.25 cents/gallon. This brings my total cost for clean, dry, acid free oil up to about 10 cents/gallon, I can live with that.

jeepin -- Tast a bit of baking soda, it is a salt, just of a different chemical than table salt. I don't know just what BS does with oil but it is an age-old product used for cleaning and bathing. If you have ever found yourself out of hair shampoo and used your bath soap to wash your hair you know that your hair feels gloppy and stickey because of the soap, if you put a bit of BS in the palm of your hand, dissolve it in a bit of water, and rub it into the sticky hair you will have squeeky clean hair (it will literally squeek between your fingers) almost instantly. I don't know what reaction causes this but the BS cuts soap and grease something fierce. why this causes an emulsion I don't understand but if the oil is fairly clean the water sure stays suspended in it.

Adding BS to clean dry oil -- Have not tried this but I think there needs to be water present for the BS to do it's de-acid thing, don't know for sure ? Other posts say oil alone can not be tested using the standard PH scale for acid/base. They always say wash the oil in water and test the PH of the water, don't know - still researching about acid and oil. I will do some tests.

Flour -- Sounds wierd but in testing I found that flour does not absorbe oil, only water, at least as I am using it. If you put a inch or so of oil in a glass and stir in 1/4 to a 1/2 teaspoon of flour really well you end up with a nice thickened gravy, set this aside over night and you will have absolutely clean oil with a thin layer of flour on the bottom of the glass the next day.
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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this is a picture of clean oil that was poured from the very top of many cubees as a test. It was stirred with water/Bs 3 days prior to this picture. There is about 1/8 inch of oil on top of the emulaion,This is the same way it looked on the second day after stirring.
Looking closely along the top edge of the barrel you can even see some dark lines in the oil, these are caused by convection currents on this hot 90 deg f day. The oil is heated by the outside of the barrel and rises , then moves inward to the cooler center where it sinks and goes aroung again.
Once I stirred in the flour I had bubbles over the surface the next day, usually takes a couple days before the oil emulsion starts to really break and the oil starts to loose the peanutbutter color. The flour ingredients list shows a bit of Folic acid as one of the smaller amount ingredients so some of the bubbles are probably being caused by this reacting with the BS?

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Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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Tim, excellent description of your well planned system.

Tell us more about your gaskets/spacers on the cartridge filter elements. I assume this is to prevent the oil bypassing over the top or bottom of the cartridge. Tell us more about what you are using for a plastic tube insert to prevent collapsing. Did you find something the right size and add some perforations?

I like your paper towel wrapping idea. Kind of a poor man's Frantz fitler. Have you seen these flushable in-line filters from McMaster Carr? Check out part number 44085K211 at McMaster. The washable screens come in sizes down to 450 lines, or less than 30 micron. Whenever the pressure climbs I just open the drain valve and it flushes the accumulation out the bottom. I use three of these inline... 100, 200 and 450 lines.

I appreciate your photos but hope someone gives you a real digital camera instead of the camera in a cell phone.

You make some excellent points of the value in pumping the same oil through the filters over and over and over.

Keep up the good work.

Todd


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Location: El Dorado, Ark | Registered: July 04, 2004Reply With QuoteReport This Post
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Yes, the seals are to keep oil from bypassing around the ends of the filter elements. The seals are simple 3/8 thick flat doughnuts cut from felt, the pressure inserts are made from 3/4 inch PVC plastic water pipe drilled full of 1/2 inch holes. (pictures here)

Paper towels -- This is someone elses idea, sounded good so I tried it.

Flushable filters -- Sounds intresting, I will look at these. I could have used one of these today, I inadvertently pumped about a half gallon of pancake batter into my filter tank, plugged up a water filter in just a couple hours.

cell phone -- don't use one, not that anxious to be interupted. Others have made similar comments about my video captured pictures, at least these are better than my earlier ones.
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post



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Tim, Forgot to say in my last post.....thanks for posting this. You got a system that works for you so stick with it unless you feel the urge.

Anyway.... If I'm not mistaking BSoda is a base so that is why it neutralizes the acids. You said you thought it was part of the Salt family. Nahhhhh. I really dont thing so.

About acids... after dewatering you may have no significant acids according to Dana. He says this is due to most the acid in there is bonded to the water in the first place.


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Location: North Tx | Registered: November 23, 2002Reply With QuoteReport This Post
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I am always tinkering so this oil cleaning procedure is not set in stone by any means, just what is working now. This approach to filtering and the addition of acetone and turpentine to the blends has all but eliminated my vehicle filter plugging problem, at least until it gets very cold.

The water washing and the BS may well be overkill, may be that the water removes the water-soluable acid from the oil and all I am doing with the BS is neutrilizing the acid in the water, don't know, should do some PH testing on the water and titrations on the oil - eventually.

Moved a barrel of washed/settled oil into the filter tank today, seems the foam on top is being made from the stuff that was under the oil that I was calling "pancake batter". In all of the BS batches there has been a much smaller pancake batter layer under the oil.

Before the BS the excess water that always ended on the very bottom of the barrel was almost clean, looked about like tap water. Since adding the BS this has changed considerably, the bottom water now is always almost black and smells pretty funky and contains "stuff", don't know what else to call it, sorta gray soapy granulated looking texture to the water.
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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quote:
...Before the BS the excess water that always ended on the very bottom of the barrel was almost clean, looked about like tap water. Since adding the BS this has changed considerably, the bottom water now is always almost black and smells pretty funky and contains "stuff", don't know what else to call it, sorta gray soapy granulated looking texture to the water.
You could do one small batch w/out B.Soda and remove the water. Then add B.Soda to the water and see what happens. Add more water B.soda solution to the removed oil and see what happnes with that. Would be interesting little experement.

Again thanks


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Location: North Tx | Registered: November 23, 2002Reply With QuoteReport This Post
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Well - This web page explains a bit of baking soda chemistry. It indicates that BS is both a salt and base.

Thinking more about the physical properties I am seeing in my settling barrels I begin to suspect that the BS has turned them into septic tanks, floaties on top (skum), heavies on the bottom (my dark greanulated water) and oil rather than water in the center, not quite what I was intending ? more reading to do.
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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Thanks for sharing, Tim. Sounds like your system solves several problems.

You may have said, but I wasn't clear on this: did you manufacture your own whole house filter housings, or did you get them from the culligan man? Smile

Coachgeo wrote:
________________________________________________
Anyway.... If I'm not mistaking BSoda is a base so that is why it neutralizes the acids. You said you thought it was part of the Salt family. Nahhhhh. I really dont thing so.
________________________________________________

I don't want to drive this thread off topic, but just to clarify, Tim is referring to a chemical classification when he calls baking soda a salt. Yes, sodium bicarbonate (baking soda) forms a base when mixed with water. It is also a salt. A salt is just an ionic compound. Lots of things that we don't think of as salts are.

(addition: As soon as I posted this, my window refreshed and I saw that Tim beat me to it.)


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Location: Alaska | Registered: April 25, 2006Reply With QuoteReport This Post
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wvoalaska -- Salts -- I am having to read up on this chemistry stuff, always something new to learn.

Filter housings -- I use the cheapest thing available at the home improvement store. Always seems to be the blue plastic housing sold as an "OMNIfilter". These always seem to be just a bit under $10.00 each. In the "filter tank" picture above you can see the bottom of the four housings that are plumbed in series, will get a better picture posted tomorrow of the filter cart.

BS as base -- I suspect this is also the reason that it creates an emulsion easily, base + water + oil = SOAP. This BS idea is looking less desirable all the time.

jeepin -- reading about salt and oil, looks like salt won't dissolve in vegoil, at least not table salt or epsom salts, still trying to deturmine about baking soda. Something about nonpolar oil solvent and polar solutes ?
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post



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Tim, I suspect that the reason you get emulsions that vary in stability is that the BS is reacting with the free fatty acids to produce soap. Soap will act as an emulsifier, so if the batch of oil has a lot of free fatty acids it is more likely to produce more soap and a more stable emulsion. BS is sodium bicarbonate (NaHCO3) this reacts with fatty acids R-COOH to produce R-COONa (soap) plus H2O and CO2 (the gas bubbling to the surface).
Also if there are other acids in the oil like vinegar or fruit acids this too will produce CO2.


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Location: Brisbane, Queensland, Australia | Registered: May 16, 2003Reply With QuoteReport This Post
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Yep, I finally realized that I could be making soap even at the low temp of 90 deg f. This is good and/or bad. The soap can cause emulsions but it also is reducing FFA's. I can now deal with the emulsions so I need to start doing titrations on the oil to deturmine the extent that the FFA oily acid content is being reduction using this method.
If the BS is making an adiquate improvement in the FFA acid content of the oil It would be nice, if not all it is doing is neutrilizing the water-soluable acids that have ended up in the wash water. This is nice for wherever the wash water ends up but is not making any improvements in the oil and it is using up an extra week of settling time - Decisions, Decisions ..

I need to read up about FFA'S and soap. I am a bit confused as to just what these FFA'S actually are. I THINK these are the carbon molecules that have been freed from the normal vegoil triglyceride molecule but have not yet linked up with any other molecule (would be alcahol in biodiesel). I think mono and di-glycerides are actually not FFA's, they are what is left when one or two carbon molecules are released from the original 3-carbon TRIglyceride molecule. Large amounts of mono and di-glycerides are not themselves actually bad but they indicate that there freed oily acid molecules are out there floating aroung in the oil someplace.

Apparently soap will more readily be made out of these now-released-and-free carbon molecules much easier than if it has to cause the release of these first and then combine them, I suspect the addition of the heat in the actual soap making process causes this extra release step when purposly making soap out of ALL the oil rather than just the FFA.s that are already floating around in the oil -- PLEASE CORRECT ME here if I have it wrong.

There are others also inquiering about reducing FFA's in vegoil (here), and also a couple of older discussions that I posted links to in that thread. I nead to re-read all these myself and try to figure if it may not be more efficient to use a calibrated amount of lye rather than a fixed amount of BS and weather this can be a one-step process or will need to be a 2-step process.

If I do an acid content deturmining titration test on the oil before doing any washing of it the test should indicate the amount of lye needed to neutrilize all of the water soluable acid and also the amount needed to convert all the FFA oily acid into soap. (HELP - HELP Chemists -- stop me here if this is wrong before I spend time doing the testing)
This should remove both the water-soluable acids and the FFA's all in the same step. More researching to do here to optimize this cleaning process.

The biodiesel folks go to pains to remove any water-soluable acid before doing this test, some even test the acid content of the isopropal alcahol used in the test, but for my oil cleaning purposes I think I want to test for the TOTAL amount of ALL types acid in the oil to do this all in one step.
The other approach would be to do a water-only wash on the barrel of oil to remove the water soluable acids. Once these acids are out of the oil then I would do the titration test to deturmine the amount non-water soluable FFA oily acids in the oil itself, this would tell me how much lye to add to the oil to remove the oily acids by turning these FFA,s into soap that will settle out of the oil. I have to research just how to deturmint the amount of new clean water to add to the oil and lye in this step.

This links to a discussion of how mcguyver is removing FFA.s using this "lye stripping" process.
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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