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

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July 08, 2007, 10:13 AM
jeepin, moggin Jessup (coachgeo)
My vegoil cleaning procedure and experiance using baking soda in the wash water.
ournal Article in Renewable Energy 28 (2003) 939-948

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July 08, 2007, 09:06 PM
Tim, I was so intrigued with using baking soda that I did a sample today. This is 6 hours in full sun after being shaken hard in to an emulsion. Yeah it sure bubbled up...AND OVER! Big Grin I'll give it a week to clear but the oil was taken from the top of a cubie set for disposal. I'm not expecting miracles.

'97 Ford F-350 7.3L PSD - Plant Drive kit
'84 Mercedes Euro 300D NA - Custom two-tank
Running on
vegoil and biodiesel since May 2006

July 08, 2007, 09:57 PM
It will evolve carbon dioxide gas, so probably worth using a larger container. Big Grin
Also add the bicarb slowly.

Big Grin
July 08, 2007, 10:29 PM
After the first hard shaking and settling, the baking soda formed between the water and oil level. I shook it again then after a while the baking soda blobs started to rise (as the oil heated up in full sun) until they were on top. It wasn't until a few hours later did I see that it bubbled over. The BS bubble stuff on top reminds me of the aerosol can of spray foam to fill cracks and voids.

'97 Ford F-350 7.3L PSD - Plant Drive kit
'84 Mercedes Euro 300D NA - Custom two-tank
Running on
vegoil and biodiesel since May 2006

July 09, 2007, 03:47 AM
Tim c cook
I am confused, did you first dissolve the BS into the water, sounds like not. I tried adding the BS powder directly into the oil/water, it did not work. I suspect the BS got coated with oil on its way to the water in the bottom of the barrel, the oil coating kept the BS particals from dissolving into the water. The BS seems to need to be dissolved into the water prior to mixing to get it to react with the acids bound in the oil.

That much foaming that fast would seem to indicate a LOT of water soluable acid for the BS to react with, with my one pound of BS dissolved into 5 gallons of water and then the BS/water stirred into 45 gallons of warm oil it usually takes at least over night to see bubbles, even longer to make foam. I usually get around a 4 inch layer of foam on the top of a barrel of warm oil after 3-4 days if acid is present, sometimes I dont get anything but a few bubbles, depends on the quality of the oil, unfortunatly, you can't tell the acid content by looking at the oil. Clean looking thin oil from the top of settled cubees usually makes the MOST foam, it even sometimes makes won't-seperate emulsions, FFA's should be lighter than oil so will end up on the top of the liquid, they are what the BS converts into soap, lots of FFA means lots of soap, lots of surfectant soap will make an emulsion that won't easily seperate by gravity alone.
November 15, 2007, 10:26 AM
Anything new since July? And Tim Cook, what if you remove as much water/bs as posible when you 1st mix with WVO. Seems like the acid in the water is making the BS bubble. So if the 1st settling of water/BS is removed, then a greater portion of the already completed reaction is removed. I would think once the water/bs settled out , that the wash proccess has been performed & no longer is a benifit. (except sitting in bottom of barrel making a bubbling reaction) acid in the water & BS. Or does the gasses bubbling up, help something? ( the gas is carbon dioxide? )

99 E350 psd
February 13, 2008, 10:10 PM

I have some off spec biodiesel. Aren't there techniques like this baking soda routine that will precipitate oout the soaps or ffas. I'm at like 2.0 mg KOH/g but need to get to the ffas to budge.

In biodiesel land I tried acid esterifucation and also a mild (.033%) NaOH (aq) solution 1/3rd vol. 3x and rechecked ffa...still llike 1.5 mg KOH/g.

Tried magnasol...didn't help much.

Any WVOer make a suggestion?
80 300D Wagon
81 300SD Turbo
87 300D Turbo
95 F-350 2X4 7.3 Turbo-Diesel Magnum (propane)
66 Volvo Amazon wagon

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June 08, 2008, 03:17 PM
If BS and the acids in the oil create C02, H2O and soap,
what would happen if I pass my oil/BS/water mix through a centrifuge?
I removed most of the water that settled to the bottom, but still have some water/BS suspended in the oil.
I am currently passing the mix through a centrifuge and i am getting 3-4" of froth on the top, and smoke (water vapor?) coming out of the centrifuge.

If I leave the centrifuge running, will the soap eventually go away? the water/CO2 should smoke/vapor out, but what about the soap?


05 CRD and 07 Dodge 2500. Both on B100
June 08, 2008, 09:42 PM
Soap creates an emulsion that is so strong the CF may not remove it. Settling (warm) for a very long time, or a very hot flash evaporator may be the only solution. This is the biggest drawback to adding BS.

YVORMV - Your veg. oil results may vary, see
95 Dodge Cummins 4x4
Zero fossil house- 100% solar power and heat.
June 08, 2008, 10:38 PM
Tim c cook
I mix the BS water with the oil and let settle/bubble for a week, depending on the amount of acids and/or FFA in the oil the bubbling may stop sooner than a week. The amount of soap produced depends on the initial FFA content, unless there is a lot of soap the oil should settle into nice visably clean oil over the second week of settling. If the oil has not started to seperate and produce a clean layer of oil on the top of the barrel by the 3rd day after bubbling stops I stir 4 cups of household flour into the barrel, this has so far always produced the start of seperation within the next 2-3 days, wait another week and pump off the top oil. It ain't fast but it is cheap.

emiperformance -- Confused, did you allow any time for the BS to react with the FFA's, BS is so mild of a caustic that it will take a few days for the reaction to complete, you can't simply mix everything together and then immediatly run it through the centrifuge, not that easy. My experiance has been that the soap drops out of the oil and sets as a layer above the bottom water but under the oil. Bonded water is part of the soap producing process so I would think soap should be heavier than oil and seperate out over time with static gravity but may not be heavy enough to work well in a simple centrifuge as it is heavier than oil but lighter than water, don't know, needs testing.
June 09, 2008, 11:27 AM
I mixed 5 gallons of water with 1 pound of B.S.
let it sit for a week, it brought the titration down to 8. I added another pound of B.S. and let it sit for another week.
I had a SLOW seperation with the one pound.

took about 6 days.

After I added the second pound, it seperated within a day.

Do I need to make sure all of the soap is out of the oil before using it to make Bio?


05 CRD and 07 Dodge 2500. Both on B100
June 12, 2008, 07:43 AM
Hey Tim,

Long time...

I have a paper towel question for you (or anyone really). Does anybody have a (good) guess of the micron rating of brown paper towels? the kind used in public bathrooms.

I've been using them wrapped around 1 micron spun filters and they reduce the flow considerably more than standard, kitchen-variety paper towels. But they sure do make the spun filters last a loooong time.


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 05, 2009, 11:29 PM
Is Tim Cook still around? I just found this place reserching cleaning a dewatering WVO for fuel. I have read until I have a headach and still do not have a satifying answer to what I need to do to have good oil to burn for fuel in my recently aquired 83 Mercedes. Tim, you seem to have done most of the work but this info seems to be a couple of years old. What is you final setup to clean WVO? Is the Baking Soda/Water bath a must to you and are you still using a Flash Evaportor to dry the oil. I would love to see a drawing of you corrent setup for cleaning the oil. Thanks for all of the info so far.
April 26, 2010, 01:58 AM
Tim c cook
Just a update - I still use this filtering setup but no longer dewater using the flash evaporator, it just used too much electricity and needed more cleaning and maintenance than it was worth. If I ran the FE at 350 deg f it would dewater in one pass so the electricity cost was not too costly but at that temperature it polymerized a good bit of stuff inside the heater pipe, this plasticized stuff would stick to the inside of the heater pipe so the heater assembly needed to be disassembled and scraped out every couple barrels of oil. The plasticized stuff in the heater pipe would also occasionally brake loose and clog the orifice, unscrewing a 350 deg f orifice fitting was hard on the fingers and was just a general pain, pun intended. By lowering the temp of the FE to 250 deg f the polymerization problem went away but so did the single-pass dewatering, I had to circulate the oil through the FE several times to insure it was dry, this increased the amount of electricity needed for heat to a point it was costing 6-7 dollars to dry each barrel. I now simply allow the output from the last water filter housing to spray back across the open top of the hot oil in the filter barrel for the same 48 to 72 continuous hours that I circulate the oil through the filters, this works fine as long as the humidity in the air is not too high and it takes no more electricity than just filtering. the oil is heated to 100 deg f but with insulation on the barrel, and with two 4400 watt 220 volt water heater elements wired in series and powered from 110 volts so they produce 550 watts, the elements last forever, still using the original heater elements after several years, chrome coating is gone but they heat just fine. It only costs a nickle an hour, or less, to heat. At temps below "0" f the heater runs continuously, above that they cycle on/off once the oil is up to temp. The 1 G/H 12 volt DC Shurflo RV water system circulation pump is powered from an old 10 amp battery charger and draws about 6 amps (around 75 watts) so it costs less than a penny/hour to run it.

This pic shows one heated and insulated settling barrel and the same filter barrel cart that I have used for oil cleaning for the last several years.

July 19, 2010, 10:34 AM

I've been using a filtering method similar to yours for some time. (Shur flow pump, whole house water filters, barrels) I added a nozzle for de-watering and have found that I have a heck of an oil mist rising off of the rig. I tried adding a deflector plate to run the nozzle against and tried running the nozzle into a stove pipe (thinking that air and water would go up and oil down)

Do you have a lot of oil mist coming off of your rig?


All kinds of Diesel engines.
Beckett and Riello burners.
July 22, 2010, 05:18 AM
Tim c cook
I had hoped to add a picture to this post but my 1.8 G/M Shurflo filter pump just crapped out with a worn out bearing, I will post a pic once I get the pump up and running again.

Way back when I tried using a shower head a couple feet above the barrel but this splattered oil all over the place and really never did dewater the oil. Now I sort of squirt the oil stream horizontally across the top of the barrel, this is actually more of a flattened stream of oil rather than an actual "spray". I brazed a 3/8 pipe "90" through the side of the barrel about 3 inches down from the top, the output of the last water filter connects to this fitting. Since the oil has to make a hard 90 degree turn just before it enters the barrel the stream is sort of flattened against the far side of the 90 and exits out into the barrel as sort of a vertical fan of oil about 3 inches wide and maybe an eight inch thick, it sprays about half or 2/3 of the way across the barrel before dropping back into the oil in the barrel.

The water seems to be released mostly from the surface of the 100 deg F oil in the barrel, on a cool day I can actually see a thin amount of water vapor rising from the entire surface of the oil as well as from the fan-shaped stream. The oil draws a lot of air down into the top layer of oil as it drops back down through the surface, these air bubbles rise up all over the surface of the oil in the barrel, I suspect it is these bubbles of air that pick up the water in the oil and then release it as vapor when they break on the surface? Not Sure, but the oil dries over the 3-4 days that I circulate it through the filters.

Someplace on these forums another person posted a picture of there similar drying setup but I have not yet found it. They plumbed something like a 3/8 pipe up over the center of the barrel close to the top, then placed a "90" degree fitting on the end such that it pointed straight down into the center of the oil in the barrel. They then screwed a hose barb fitting into the end of the 90 as a slight restriction so that the speed of the oil stream was increased, this solid high speed stream of oil pulled a LOT of air down into the oil as it entered the oil in the barrel, a lot of bubbles caused a sort of foaming on the surface of the oil that released a lot of water vapor. This setup probably dries oil faster than my similar horizontal stream but as long as my setup gets the oil dry by the time I am done filtering I am happy.

Messy splashing - I don't have too much of this as long as I keep the surface of the oil in the barrel about 4 inches below the oil stream inlet, the inlet is about 3 inches below the top of the barrel. I have this set up outside and I do get a bit of splash if the wind happens to blow hard from the wrong direction but if it were out of the wind there would not be much of a problem.

I will add a picture of my horizontal oil stream once I get the pump running again, if I find the other vertical stream picture I will post a link to that too.
July 23, 2010, 04:33 PM
Since the oil has to make a hard 90 degree turn just before it enters the barrel the stream is sort of flattened against the far side of the 90 and exits out into the barrel as sort of a vertical fan of oil about 3 inches wide and maybe an eight inch thick

OK, I hooked up an actual spray nozzle that definitely is atomizing the oil.

The oil draws a lot of air

Yes, major "venturi"? effect going on with my nozzle too.

My oil foams on the top but the air quickly releases if the pump is shut off.

I believe that the nozzle is removing a lot of water. My finished product has never looked so clear.


All kinds of Diesel engines.
Beckett and Riello burners.
July 30, 2012, 12:27 AM
Tim c cook
I forgot to add any pictures of the current "squirt a stream of warm oil directly down into the warm oil in the barrel" dewatering setup so here is a picture of the plumbing with a 3/16 inch restriction (1/8 inch pipe nipple) in the end that I added to get the "squirt" directly over the center of the barrel. The squirt is pretty gentle but since it runs for the entire time the oil is circulated it has removed the water just fine so far.

July 30, 2012, 12:29 AM
Tim c cook
this is a picture of the complete filter barrel setup, looking a bit worn after 6 years or so of use but still doae the job just fine.

July 30, 2012, 05:12 AM
I have heard of that squirtng the oil straight in some years ago. Big Grin
Seems to work pretty well from what I have heard. I believe it can work better still if you put a fan blowing across the top of the oil or increase the pressure of the oil so it churns up.

With your filters, are they all the same rating or are they progressive?
If they are progressive, can you tell me the reason why you do it this way? I'd also like to know how you work out which one is blocked when the flow stops or do you just change them all at once?

I have seen this progressive method many times but I could never understand the logic behind it.
Given you are one of the sharper tools in the shed, I'd be very interested to hear your feedback on this Tim.