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My vegoil cleaning procedure and experiance using baking soda in the wash water.

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June 20, 2006, 03:00 AM
My vegoil cleaning procedure and experiance using baking soda in the wash water.
I know everyone has there 2 cents
So here goes. What about testing the ph in your oil by swishing it w some water while it is still dirty, then testing the water. Then test it again after you have water washed or cleaned w BS.
By the way, what is the acceptable ph level for wvo?
June 20, 2006, 03:21 AM
Tim c cook
erikk -- Yes, I will start testing and keeping records as I clean more oil.
It will be interesting to see if my cheapo surplus PH test strips will give any indications when testing the wash water.

PH of oil -- From what I have read oil does not actually have a PH, or at least PH is not what it is called ?
Apparently oil can't be tested for acid the same way as water.

The "titration" test done on the oil when preparing to make biodiesel gives you a "relative" indication of how much acid is in the oil based on what ever chemical "base" you are using in the test. I am not sure myself how water-soluable acids in the water in the oil show up in this test. I wonder if I could use a baking soda/alcohol solution in the test instead of a lye/alcohol solution (will BS dissolve in alcohol ?). This would give me a direct reading on how much BS to use. May not be nescicary IF BS does not actually produce soap from the glycerides but only from the FFA,s. (anybody know ??)(GraemeW hinted at this in his post, second from bottom of page 1). If that is the case then all I need to do is add more than enough BS and the excess will go out with the wash water ??
Should have paid better attention in those high school chemistry classes.

I just read through the above linked discussion on "lye stripping" again, mcgyver's description of the physical aspects of his stripped oil match my oil pretty close with the exception of jelled soap on the bottom. I suspect that my grainey soapy bottom water is actually soap but in a lot less quantity since BS is a lot less BASE chemically than lye is. I also don't think my oil was any where near as bad as what he was testing so it should not make nearly as much soap anyway.

I definatly will start titrating my oil before and after washing. Maybe BS is not such a bad idea after all.

Wish I had better understood the value of mcgyvers testing when he first posted about this, only took me a year to catch on, faster than usual though.
June 20, 2006, 03:52 AM
Tim I would not stress too much. Your oil is going to be far cleaner than most and any free fatty acids left in your oil, if one is to believe the consensus view, will do no harm.
Also if you look at the colour of the froth on the top of your oil there appears to be some froth flotation processes at work.
Tha one pound of BS is capable of neutralising about 3 pounds of free fatty acid. As most used oils have about 2% free fatty acid content so 100 pounds of oil would have about 2 pounds of FFA. So for high quality oil your one pound is close to the mark.
Have a look at these to get a bit of the chemistry; -

1977 Mercedes 300D 2 Tank HOH, Heat exchanger and Vegetherm.
June 20, 2006, 03:57 AM
Tim c cook
GraemeW -- Thank you VERY much... Good to know, HELL, it is GREAT to know..
Looks like the one pound may be a bit shy for the 40 gallons of oil (roughly 300 pounds) I am processing in each barrel, I will titrate with the one pound and also do a few tests with two pounds.
June 20, 2006, 07:00 AM
I too the idea of getting as much of the FFA's out too to prolone my vehicle's IP/engine life. At this point I don't do- just the settle for 2+ wks > standard filter > heat dewater for 12 hrs cycle(no washing at any stage). If I go the the effort of doing anything more I want to make sure that is effective and efficient in terms of time and money .

I have seen a large number of baking soda and salt filtering posts / threads over at the Greasecar forums - / search baking soda - . Brian
Miller aka Forrest Gump seems to have a good handle on this but I am not sure if he has explored the FFA (and glycerin soap issue in detail) .

1994 F250 IDI 7.3 NA E4OD

Remember that the forum search/"find" feature does not include the archives . Search the forum archives here-
June 20, 2006, 09:37 PM
Tim c cook
rkpatt -- I haven't read all the BS posts everywhere but the ones that I have read seem to be using the BS and salt to suck water out of oil -or- so the salt/BS dissolves in the water in the oil to make the water heavier and more likely to settle to the bottom, at least I think that is the theory. I could be wrong - GraemeW's first chemistry info post indicates that the BS reacts with the FFA to produce soap, water, and CO2 -so- the idea may actually be for the BS to do it,s thing with the FFA,s and the salt is there to remove the produced water. Not sure - the BS posts don't ever seem to be clear about what thy are attempting to do. I have not read any of these in several months so I need to check them out again.
None of the other BS posts that I have read were deliberately stirring in large quantities of water as part of a cleaning process.
June 21, 2006, 10:13 PM
It seems to me that this could lead to the Holy Grail of biodiesel manufacture-the continuous process. The biggest problem with biodiesel manufacture is that all WVO has slightly different properties, especially FFA content. You could use a 2 stage process, the first would be eliminating the FFAs and then your catalyst would always have the same properties. You could mix up a years worth and it and it'd would work for all of your oil.

You would use batch processing to pretreat your oil then a continuous process to manufacture the biodiesel.

I'll be working with my problem oils and let you know how things go.

Thanks Tim...nice work. And nice bit of valueable info, GraemeW

walk softly, leave a small footprint and a big impression
June 21, 2006, 10:59 PM
I started a thread over on the biodiesel side here.
There are a lot of brilliant folks over there who don't often visit the SVO world. It might be a good meeting of the minds so please pop over and give some input.

walk softly, leave a small footprint and a big impression
June 22, 2006, 02:24 AM
Tim c cook
bio-LOGIC -- I think you just described a slightly different approach to the base/base 2 step biodiesel making process. There is a seperate heading about this process on the first page after clicking "biodiesel".

There is also a way to save the FFA's to use in making biodiesel called the "acid/base" process.There is also a seperate discussion area about this process under "biodiesel".
June 22, 2006, 10:08 AM
Tim, I realized after making the post that I hadn't described the topic correctly. My goal is to skip the acid wash to reduce FFAs before the standard WVO-methoxide reaction.

Doubtless, I still have a lot to learn.

walk softly, leave a small footprint and a big impression
June 22, 2006, 04:40 PM
Tim c cook
bio-LOGIC -- I just read your original post on the biodiesel side - sorry, now I realize you were fully aware of the verious 2-step processes.

Comparing the caustec strengh between BS and lye I wonder if the lye process would end up costing less with realy high FFA oil, not sure, but is definitely seems to be an overnight, or worst-case, 2 1/2 day process, compared to the 7-10 days I am seeing with using BS. Lots more testing to do.
June 22, 2006, 07:07 PM
Todd T
If you're going to go to the trouble of handling caustic, why not go all the way and make biodiesel. The baking soda is so safe to handle. Using caustic would require a lot more gearing up for safety.

Hmm.... here's something. I have some old Sodium Hydroxide 50% (in water) that I don't want to use in my chemical blending. I might try some of that to neutralize the FFA's and to do a water wash at the same time. Sounds like something for lab testing first.

I like baking soda for the safety.


2002 F-250, 7.3l on WVO since '04
'82 VW Rabbit diesel 1.6l na
'83 GMC 6.2l Class C RV
'85 F-350, 6.9l flat bed
'85 E-350, 6.9l cube van
2 Mercedes 300SD's
3 Chinese Changfa-style diesel generators- 12kw, 8kw & 7.5kw
Mitsubishi 3 cyl diesel generator/light tower
Kubota 2 cyl. diesel, water cooled air compressor
Onan 12.5kw air-cooled diesel genset
I run my company entirely on renewable energy including electricity from generators running on biofuels.

June 23, 2006, 01:05 AM
Tim c cook
I think I will use the BS from now on, It adds an extra week to the settling time but I am already doing the water-wash with great success and have already doubled the number of settling barrels so no big deal. I can buy generic 1 pound boxes of BS for 39 cents each so there is no real cost involved. I have to re-learn about doing titrations and probably should get some phenothalene to replace the phenol red that I had used, supposed to be more accurate, especially on oils with higher FFA amounts ?

One thing I have observed is that when cleaning what looks like the cleanest oil or when testing using the cleanest oil from the top of the cubees, I get won't-break-without-flour emulsions. Reading about FFA chemistry, they are the lighter cleaved off clumps of hydrogen/carbon molecules of verious description -but- they were originally part of the bigger triglyceride molecule, since they now are free from the big molecule they have to be lighter than any of the glyceride molecules, being lighter I bet they rise to the top of the container if it settles for a while. -so- the nice clean oil from the top of the dunpster/cubee that we think of as the best oil probably actually containes the MOST FFA of any oil in the container.

Seperating high/low meltpoint oils -- I think I am changing my approach to doing this. I made a post above about seperating 25 gallons at a time in an old refrigerator, this is slow and uses extra energy due to needing tp reheat the cold oil for pumping etc. I just moved a 10 gallon batch of oil that I had cleaned/dewattered about a month ago, it took that long for the high meltpoint stuff to actually end up as semi-soft white stuff on the bottom of the tank, and this has been with daytime temps up around 90 degrees. Even I don't want to have to wait that much time, especially for just 25 gallons.
I picked up a 500 gallon steel tank recently, I also have an old military 1977 dodge 4 X 4 ambulance with a nice insulated box that I was wondering what to do with, it is too small for a comfertable camper and I no longer need it to use as the portable tool truck that I originally bought it to be. The 500 gallon tank will fit nicely inside the insulated ambulance box. I think I will add electric heaters and verious plumbing to the tank, slide it inside the insulated box, add a small window air conditioner to the box and heat/cool all 500 gallons at one time.

By pumping oil from the bottom outlet I should get the more solid hydrogenated and fats to put into the heated second tank and by pumping from the top using an internal floating pickup I should get the lighter oil to use for blending.

And the entire 500 gallons is out of sight and self-propelled.
June 25, 2006, 01:23 AM
Tim c cook
Thebushpig made a post on another thread (here) concerning using TOO MUCH baking soda.

This is a question I have been trying to answer -- Will the BS react directly with good vegoil as well as with the excess Free Fatty Acids that are in used veg ?

In posts and on the BS chem info web pages it states that the BS reacts with FFA's to make soap but says nothing about it reacting with glycerides directly. If the glyceride (vegoil) molecule is intact then its acid portions are not "free" to bond into soap - True/False ?

Also, does water need to be present for this soap reaction to occur, if so, is the amount important ?
June 26, 2006, 09:47 AM
It's been a few years since I've (intentionally) made soap, but I do remember a few basics:
1. water is ABSOLUTELY necessary for saponification
2. the amount of water is very important (if the density of the final soap is important)

As always, I really appreciate your experiments. (I just wish we lived closer so I could come over and play.)

This message has been edited. Last edited by: PerkHouse,


2000 Jetta TDI
1982 Mercedes 300D Turbo
1986 Isuzu P'up (NA)
1985 Mercedes 300D Turbo
75/25 WVO/D2 for warm weather
50/50 WVO/D2 for cold weather
Uniqueness is a treasure not to be buried. - Laurence Martel
June 26, 2006, 03:05 PM
I started out with a 55 gallon barrel of WVO that titrated at 30 g/l using KOH. I added 5 lbs of BS and it bubbled for a week and now titrates at 23 g/l.

That's progress. I'll add another 10 lbs and see where I end up.

I'll let you know.

walk softly, leave a small footprint and a big impression
July 26, 2006, 10:19 AM
tim i think you have stumbled on to something inportant here i too have injector pump problems i have ran 30,000 miles of straight veg and i dont do the baking soda or flour thing ! what is the name of that process emalsion ? i think i need to stsrt i have exprirence injector pump damage and a series of lift pumps i think its due to high acid ? trying to learn how to start testing it / can you help me in any of these areas ?
Originally posted by Tim c cook:
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.

avoid paying the man
July 26, 2006, 10:25 AM
sorry for the bad spelling guess i should have used spell check !
also what does a flash evaporator do ! thanks for the pics but there hard to see! what and why is the process of that ?

avoid paying the man
July 27, 2006, 06:53 AM

The flash evaporator is a device for removing ALL of the water from the oil in a single step. Tim's design is low-cost to build and low-cost to operate. The most expensive part is the pump (and motor). And while Tim had a lot of success with a Shurflo pump, my experience with Shurflo hasn't been as good, so he's helping me with putting together a pump designed to pump oil at medium pressure (150-200 psi) and flow rate (3 - 17 gal/hr). Come on over to the FE thread...


2000 Jetta TDI
1982 Mercedes 300D Turbo
1986 Isuzu P'up (NA)
1985 Mercedes 300D Turbo
75/25 WVO/D2 for warm weather
50/50 WVO/D2 for cold weather
Uniqueness is a treasure not to be buried. - Laurence Martel
July 29, 2006, 02:35 AM
Tim c cook
Phil -- Testing for acid -- Go to the biodiesel side of the forum and click the "find" button at the top of the page, type in "titration" (without the quotes), this is the normal test used by the biodiesel folks to deturmint the amount of acid in the oil, it is needed to figure out how much lye to use in the process but the answer to the test will also tell you how "bad" (acid content) your oil is.

The FE heats the oil to 300 degrees under 150 pounds pressure and squirts it as a tiny stream into a solid bash plate to break up even the tiniest water droplets that you can not see with your eyes and that take forever (if they ever) settle to the bottom of the oil. This heat/pressure and mechanical bashing causes the water to burst into steam and seperate from the oil.
This is another link to the same flash evaporator discussion. Most everything we have learned is posted there.

There are also other discussions about lowering Free Fatty Acids in the oil here, it has progressed to folks using sodium carbonate, This is also known as "washing soda" or a pool chemical called "PH up", it is also called "soda ash". The sodium carbonate is doing an even more effective job than the BS (sodium bi-carbonate). I have not done any testing of the washing soda yet.

Another similar discussion is here.

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