Dry fuel is the single most important factor for successful long term operation of any diesel fuel engine or turbine. Vegetable oil, and especially the contaminants in used VO absorb and retain moisture/water. If one takes a well mixed sample of used VO one will very likely find enough moisture present to show on a hot pan test . If one then chills the used VO and lets it settle so the water absorbing contaminants [animal fats, trans-fats, saturated fats, hydrogenated oil, food particles, burnt bits, etc] fall out of the mix, then HP tests the two fractions, where would you guess most of the moisture is?

I use cold upflow settling to remove all those contaminants listed above, along with all the water which will react to a HPT. Clear, dry, clean VO with NO contaminants gives the fewest problems when used as diesel fuel, regardless if its being used as 100%SVO, blended VO-ULSD mixes, or transmogrified into biodiesel.

Plant oils are generally too viscous to be used directly in diesel engines unless the ambient temperature is above ~80°F, and even then only in some of the more simple mechanically controlled engines. To use veg oil in all engines in ambient temperatures below 80°F the viscosity must be reduced.

One of three methods is generally used to lower the viscosity for trouble free operation at normal engine temperatures:
1-Convert the oil chemically to biodiesel, using alcohol and caustic to remove the thicker glycerin component.
2-Heat the fuel system to above 80°F and the oil to >150°F before the IP,
3-Dilute the oil with solvents, after first removing the oils and fats that separate out below 80°F.

Most combustion chamber deposits occur with cold engines at start-up with any fuel. The important point is to completely burn the VegOil. The greatest amount of pollution and damage will occur with high percent blends of cold VO fuel in cold engines. Cold starts can form excessive deposits and produce toxic emissions. Both the engine and the environment are potentially harmed. Engine pre-heating and fuel system heating can both contribute to more complete VO combustion with VO blends or V100 a.k.a. "SVO". Prewarming the engine to 68°F can reduce harmful engine deposits, especially with VO fuels.

Older simpler engines in warm climates where it never freezes are much more tolerant to fuel contaminated with water and other stuff. Modern engines operating in frigid climates are very sensitive to contaminated diesel fuel. Pilots in the north always drain samples from the bottom of every fuel tank and visually inspect the sample for any cloudiness indicating moisture or other contamination, before taking off. Where they work there is no margin for error.

This drawing shows a simple VO cleaning system.

http://www.frybrid.com/forum/attachment.php?attachmenti...9&stc=1&d=1193006636

The processor consists of a 10 gallon barrel with the bottom cut out, and mounted open bottom up bung-to-bung with a 2" close nipple onto a vertical 55 gallon settling barrel. A 2ft piece of 2" exhaust pipe with the top end flared, sits inside the nipple coupling and ensures that the new oil is delivered near the bottom of the settling barrel. Steel pipe is rated by inside diameter and exhaust tube is rated by outside diameter, thus they fit well together.

Primary filtration is through bugscreen and pantyhose on a simple 2x2 wood frame that sits on the rim of the 10 gallon 'funnel'. The oil settles in the barrel and every time I add oil into the settling barrel, clear oil is forced out of the 3/4" bung through a street elbow, a hose bib valve and through a clear vinyl tube to the canvas bag 'jeans leg' ~ 20 micron bag filter assembly, into the final filter barrel. I find that the 30 gal poly barrels are more convenient for the 2nd stage, and use two of them as collection/final filtering barrels.

For making biodiesel, the oil off the top of the first barrel is ready for processing.

Final filtration is by rotary hand pump, through a whole house filter assembly with a 5µ filter cartridge. The barrel pump I use is a rotating-vane, positive-displacement, self-priming type which can pull or push equally well. The 2nd barrel can be heated or the VO diluted with ULSD or kerosene, to make final filtering easier.

This system works best with no heat at temperatures below 65°F to remove saturated fats and hydrogenated oil, or low power [less than 100W] evenly distributed heat if one wants to keep them in the mix. If one does a hot pan test on the oil in a cubie, one will discover that as one goes deeper in the cubie the amount of moisture increases. In my experience most of the moisture is in the sludgy emulsion of animal fats, hydrogenated oil, and food particles in the bottom layer. Since this is the stuff that causes most of the problems with cold blend fuel systems, I use the unheated upflow settling to separate and remove the troublesome sludge and the moisture it contains.

The canola oil I use is clear and reasonably dry to start with, hasn't been mixed with animal fats, and my supplier puts it back into sealed cubies while it's still warm. The cubies sometimes settle for months and I decant the clearest portion off the top into the processor. A cubie spout makes it easier. I pour a bucket or cubie of oil into the 10 gallon barrel and let it do it's thing. The oil that comes off the top of the primary filtering upflow settling barrel is dry.

This VO cleaning system is based on the simple principle that water, wet oil, fats, and most other contaminants are heavier than clear dry oil. Suspended water and oil bonded with suspended water is heavier than clear dry oil, therefore it will not float to the top. Because the 'new' oil is placed at the bottom, any water, wet oil or food particles will NOT float to the top if the oil is not heated. If there are no convection currents to mix the oil then the clear dry oil comes to the top and the contaminants stay on the bottom. This cleaning process is called "Upflow Settling". This first stage gets VO so clean that very little builds up in the bag filter and the cartridge filter is good for hundreds of gallons.

Observations indicate that a couple of material properties make upflow separation work. Water molecules are more likely to be attracted to, and bond with, other water molecules, food particles and hydrogenated oils and fats, rather than bond to clear dry oil molecules. Because these contaminants are all heavier than clear dry oil, they fall to the bottom of the barrel. The 2" drop tube introduces the newest oil into the bottom 1/3 of the barrel, this gives any moisture laden particles and entrained water the opportunity to bond with the sludge. Without the drop tube the system won't work. The other factor is that the clear dry oil molecules are the lightest substances in the whole mix, and if the mix is introduced near the bottom, only the lightest molecules will float to the top. The water, moisture, entrained water, dissolved water,suspended water,...a.k.a. whatever, stays at the bottom if there are no convection currents, because it is heavier than clear dry oil. With time, water molecules, free or attached find other water molecules and bond, this process eventually makes drops of water large enough to sink to the bottom.

The slow rate of new oil introduced is controlled by the valve on the clear oil output tube to about 10gal/hr. No modifications to the 2" x 2' dip tube required. The valve can be adjusted so the oil is introduced slowly to reduce any turbulence mixing the sludge in the bottom 1/4 of the barrel. Only clear dry oil comes off the top, it couldn't be easier.

In this cold climate I don't use solid oil for motor fuel, at any time of the year. This settling process removes it as a fuel system contaminant. The thick, wet sludge is occasionally pumped off the bottom of the barrel and mixed with sawdust for woodstove fuel. That sludge is a valuable resource for me, when mixed with sawdust from chainsawing fuel wood and packed into 1/2 gallon [2 Liter] milk cartons. One of those on a wood fire first thing in the morning quickly warms the house right up to comfortable temperature, especially when it's 30 below. There's a lot of BTUs in a half gallon of transfat oil/fat soaked sawdust.

Cold processing is more effective with reasonably clear used oils that don't have a lot of hydrogenated oil and fats, and may not work with all oils. The sort of wet, goat-vomit, grey-mayonaise, hydrogenated crap that some have to contend with probably won't come out much cleaner. Cold Upflow Settling basically separates heavier crud from clear oil.

The processor is in an 8 x 8 unheated shelter tent. The processing for winter oil 50VO/50ULSD base mix is done by freeze-up in late October. Even when it's below freezing the system will work to about 0°F to process clear liquid canola. No added heat, just gravity. The system has been producing clear clean dry oil for more than two years, used for diesel fuel mixes in temperatures to 30 below, on a few vehicles, with about 40,ooo km total so far and no problems or anomalies whatsoever.

This is one of the simplest continuous process systems that requires no electricity. It can be easily assembled with a few commonly available materials. For those who want more, it can be expanded easily with additional barrels and a small electric transfer pump.

It won't produce huge volumes quickly, but it can be up and running for less than $100 while you design, develop and assemble your Ultimate-SuperMega-HyperspaceCentrifuge-VO Processor.

The basic principle of upflow settling can be successfully incorporated into other cleaning systems..

If cold upflow settling does not produce clear dry oil for your 'WVO' and your specific conditions then heated upflow settling may work for you.

Those like Ron Schroeder who developed heated upflow settling know that even heating and good insulation are essential.

Here's his description of the system he has used for nearly 30 years.

quote:

I have a trouble free settling system that gets me more than 1000 gallons thru a 2 micron Racor filter element.

My settling tank is very evenly heated and well insulated. I introduce the oil into the bottom of the tank slowly to not stir up the oil already in the tank. The outlet is about 6" from the TOP of the tank so I am only draining the top 10% of the oil in the tank. The outlet gravity flows thru the 2 micron filter into my storage tank. If I put 5 gallons into the tank a day, it takes over a week for that oil to work it's way up to the outlet. by that time almost all of the water and solids have settled out. I get over 1000 gallons thru the filtering station filter and I have NEVER had to replace an in the car WVO filter even after 70,000 miles on WVO.

I use a settling tank that has a little more capacity than the amount of oil I use in a week. With PHO Soy, I ran a little over 120F in the settling tank and about 80 in the storage tank (I am intentionally keeping the animal fat clear). With Canola, I am running about 100F.

No problems with polymerization.

I can heat it either with hot water from my boiler or with electricity. The tank is wrapped with PEX pipe with a spacing of about 3" turn to turn and is also wrapped with ice melt cable between the PEX turns.

The water loop is fed from a tempering valve so a constant water temperature is circulated around the settling tank. The circulating pump that I am using only draws 5 watts.

The electric heat is controlled by a proportional controller rather than an on/off controller. Once up to temperature, it takes less than 60 watts to maintain temperature. With good enough insulation a 60 to 80 foot ice melt cable will get you over 200F. That temperature will probably damage the cable. I have had no problems up to 150F.

Normally I just use the circulating hot water heat.

I also heat the incoming waste oil with an inline thermostatically controlled electric heater (like a 120V version of a veggietherm) to the same temperature as the tank so there is no temperature differential between the incoming oil and the oil already in the tank.

My in home filtering has been working so well that I used a stock fuel filter for WVO on my last WVO conversion ('85 MB 300D)


Ron
'85 300D
Since '81 former WVO conversions:
'83 240D
'80 Audi 4000D
'83 Isuzu Pup
'86 Golf
'76 Honda Civic with Kubota engine
Several generators
Kubota Tractor

This message has been edited. Last edited by: john galt,

Thanks John, I like the proccess. do you have a possum mobil? when you temps are 70degrees, approx how many gal per hour do you regulate thru your valve on the 10 gal bucket? If I read your post correctly, you blend only with 50% ULSD? The only fear i have is, my wvo is not good enough for this . I think my 1st drum would get too thick of gunk at bottom too quickly. (a steep cone bottom at 1st drum would be the ticket for me.) And lastly what is the quickest way to light your sawdust/gunk log? detinator cord? Or do you start off with a real hot wood fire first?

I regulate the flow from the upflow barrel to about 10gal/hr. The valve is on the output of the 55gal upflow barrel.

Because I'm mixing ULSD-VO blended fuel, I've added a couple of intermediate barrels to the simple set-up described above. The output of the upflow barrel goes into the 1st intermediate barrel. I pump off the top 3/4s of that barrel into the 50/50 dilution barrel, then through the bag filter into the final filter barrel. I use a small fractional HP 2GPM pump for transferring between barrels.

I put the sawdust/oil brick on a hot fire; it burns much cleaner that way. I never tried det cord, the results would be interesting and no doubt spectacular.

i guess what i dont understand about your process is a friend of mine settles oil for 3 weeks before pumping the useable stuff off the top but yours is settling faster how is that?
I am filtering oil right now through some linen over a 25 g clear plastic tub and its just dripping , maybe 2 g. per hour . I'm fine wih that as long as i can pour 5 g. in at a time and walk away for a few hours I'm going build a frame to hold my pre-filter fabric so I can pour 10g in at a time. how long does it take the water and snot to fall to the bottom in your system ?

I think I'm gonna do this. But just to be clear, John, you do not wash & the final, upflowed, oil passes the hot pan test?

Yes, that is correct.

john once I get my first 55g load of oil in the processor is there a recommended time to settle it before pouring anymore in ?

Wait a few days, pour a gallon of oil into the processor, then check the oil coming out for moisture. If it's wet wait longer, if it's dry you're good to go. As you start using the upflow settling system, measure the moisture content of the oil coming out to determine the necessary retention time for the specific oil you're processing. I run about 10 gal per day, which gives about 5 days settling, for clear dry oil.

do you think the process would be more efficient if I stack two 55 gallon drums . Hopefully allowing me to use more oil per week and work the gravity angle even harder.

Yes, I would think so.

i think so too and wrap the top tank bottom with a heat strip thinning the oil in the top drum causing the particulate to fall to the cooler bottom tank . any suggestions or criticizms

John. Nice system.
Now am i correct in reading that you never
use 100% Svo. Just a mix of dino and svo.
I am designing my system now (merc 300 sd on the way). Would this work with svo/wvo if i can keep it warm enough? This would be the key so i am designing a greenhouse and solar with the ability to shut of the power(sun) when need be.

I use the upflow system to clean and dewater recycled canola 100% VO. I dilute the clean 100% VO 50-50 with ULSD before it goes through the final filter.

I built an upflow settling unit last week, and filled it to the top of the settling drum and it has sat for a week. Today I added about 10 gallons and opened the ball valve so the oil trickels into the collection drum. The question I have is: what is keeping the oil from the top container from seeping between the muffler pipe and the pipe nipple? (it is not a tight fit) I had the muffler guy swedge the end so it would sit on the nipple by gravity. Does it sound like I have done it correctly?

On my upflow barrel the flared exhaust pipe fits tight enough in the 2" pipe that very little leakage will occur. The path of least resistance is down the 2" hole not through the thin crack around it.

How does the oil coming off the top test for dry?

quote:

Originally posted by bigdingo:
do you think the process would be more efficient if I stack two 55 gallon drums . Hopefully allowing me to use more oil per week and work the gravity angle even harder.

I was thinking of doing this for some friends if I can't find a suitable size hot water tank. On the water heater I was using before, I simply pumped in from the bottom to push out the clean oil out from the top. There were no pipes running internally from top to bottom to complicate things.

If you used the 205L drums, my thoughts were to cut the bottoms out of both drums and weld them together there so you have the original fittings to use at the top and bottom. You have one fitting for filling the drum from the bottom, one for draining off the crud every so often and a fitting at the top to connect your output hose to.

As the tank will be quite tall, you will have to push the oil in with the aid of a pump. On my water heater setup, I used a $15 marine bilge pump in a plastic bucket which I filled from the cubees I collected the oil in. Because the pump is pushing against the head pressure of the tanks, the output is quite slow which is just what you want to avoid stirring the bottom layer as much as possible.

I would drain my hot water tank almost every day to keep all the crud at a minimum. Just a liter or two till I saw the fat change to oil. I gave this to a friend who would heat it, filter it and dry it and then make bio from it. No waste at all!

I wouldn't bother adding a heating element. If you leave it long enough, ( a month in my case) the top oil is just beautiful on its own. I found a month was a good time for the oil I got so if you use up to 400L a month, you'd be right with a double barrel arrangement and if you need more, you could perhaps add a 3rd drum or if that's a bit tall for you, make up a second double drum setup and T the 2 setups together which will give you double the capacity with only a few extra fittings needed. I like to have a reserve myself as a buffer to make sure things are right and so I have plenty in reserve to help out friends that are always running short.

If it is possible at all to get oil out of this setup that will pass a hot pan test, you will need it settling for a lot longer than a month so if you are not going to dry the oil after settling, I would be aiming for the longest settling time possible to reduce the water content as much as possible.

I have just gone to a double IBC setup which with my current use, will give me 10 months settling time. As I have filled my IBC's and still have the better part of 2000L settling in 205L drums, and will continue to presettle / store my newly collected oil in those, I can see the oil I put away today not being put into my car till somewhere around new years.... 2010!

Thats the problem we are trying to overcome ,different oil , source , location , vehicles . But trying to develop a one size fits all easy solution for processing.
I think it will happen if it hasnt already. I'm hoping on combining two techniques the (1)upflow and (2) heat to give me usable oil in a week or month at most . The plan now is to stack the drums with the top one upside down and connect them with plumbing fittings. Paint the top drum black and maybe the top 1/3 of the bottom . I am hoping that the heated thinner oil on top will cause heavy and wet components to drop out of solution into the cool oil on the bottom .. I need practical input on this idea . I live in louisiana and any thing painted flat black would be hot 9 months out of the year. Will convection kill this idea ? If I have a two tank system and switch back to dino at shut down protect me from water problems?

Those like Ron Schroeder who have good success with heated upflow settling know that even heating and good insulation are essential.

http://biodiesel.infopop.cc/eve/forums/a/tpc/f/15960555...241093981#2241093981

The messages at the link describe the system Ron has used for many years.

Solar heating on a dark barrel is usually quite uneven, as a result it stirs the oil and makes water separation more difficult.

John,

Thanks for the link to my HPT.........

Sorry for the mundane voice.

That oil went through a few freeze/thaw cycles and the sludge is quite thick at the bottom of those cubies. As you could see, the oil was quite wet. And, that was drawing from the top inch of the oil level.

I understand you get great results from your upflow system.

Any thoughts from anyone as to why this oil that was sitting undisturbed for a year was so wet at the top?? I was frankly shocked that the 1st cubie was so wet.

C.

I was also surprised by the moisture levels in apparently well settled samples. I'm wondering if the source and the use period of the oil could be a factor. How does the oil titrate? I suspect it has high FFA levels, and it's known that FFAs, animal fats and PHOs absorb and retain moisture. Asian cooking is known to produce fat, wet, salty, well used oil.

Consider taking a sample off the top, titrating it, and if it comes out high then do a water wash with bicarbonate of soda to neutralize the FFAs. Observe any change in the color of the settled wash water or oil, and after a week test the top layer of settled oil for moisture and titration value.

My VO is much lighter in color, more like honey, titrates around 2 and has only been used one week for fish and potatoes. I also cold process. I find that between 30°F and 40°F is the best temperature to process recycled canola. The layer of crud and moisture is solid in the bottom of the cubie and it's easy to pour off the clear drier oil.

I admire how you stayed with the script, with a calm reassuring voice, heating oil to smoking temperatures, while fire sirens wailed in the background.