Vessel for drying

[PeterAC Senior Member Find all posts View Profile Close PeterAC]

After reading the post by cgoodwin of Frybrid I would like to inquire about what suitable comercially available non-metal drying vessels are out there. He uses a ceramic lined water heater and heats the oil to 140 degrees F to drive off the water. Do we have ceramic lined water heaters in Australia? What other options are there specifically for heating. Also mentioned is a vacuum pump but I have no concept of what that is or how it works or its pros and cons to remove water. If any one can elaborate on it I would be grateful.

Peter<><

[cgoodwin Junior Member Find all posts View Profile Close cgoodwin]

Re: Vessel for drying

“Heating is a very expensive, inefficient and resource hungry way of drying oil.
I also have doubts as to how helpful it is in preventing Poly which I think is Chris's main concern.”

You completely misunderstood my post, I will attempt to make it as clear as a drum of waste oil.

The system I use complete with plans and parts sources (although in the land of Oz you will likely have to find others) is outlined at www.frybrid.com/filtration, I do not sell these plans nor any of the parts, I figure that if people have good dray clean oil then they wont have issues with the fuel systems I sell them, I also do not sell to Australia as shipping would make the stuff too damn expensive. I say this to make it clear that I am not offering advice in an attempt to sell anyone anything.

The idea behind my filtration system is this: Pour the waste oil through a bed sheet stretched over a drum to pre-filter the big stuff out of the oil, this actually takes it down pretty far and the less particulate matter (insoluble’s) the less water as most of the particulates contain water in one form or another. Once the drum is full it is allowed to sit for at least a day although some times I skip this step because I have seen all the oil I have poured in and none of it was particularly suspect. The oil is then pumped into the Frybrid Still which is a simple electric water heater with the upper element disabled, I use 220vac water heaters and then wire them at 110vac to reduce the amount of heat produced by the element although you can just buy a lower wattage element – the goal here is to slowly heat the oil and not to burn it to the element.

Once in the still I turn on the power and typically it takes about 3 or 4 hours to bring the oil in the still to 140F +/-, this is not done to boil the water off if that were possible it would have already happened in the fryer. The water we are dealing with is filled with water soluble salts, fats and acids and these change the boiling point of the water and act as emulsifiers keeping the water in suspension. By heating the oil we lower its viscosity and we get all the atoms vibrating , this allows the water which is heavier than the oil to agglomerate and the small droplets begin to form larger droplets and they drop to the bottom. We turn off the heating element to stop any convective currents in the still that would carry the water rich oil back upward and allow it to settle for several hours or overnight.

A water heater will typically have either glass or ceramic lining, if it did not then your tap water would be all rusty wouldn’t it. They also have a drain at the bottom and multiple fittings on the top and sides. They are also insulated so once you heat them up the oil inside will remain hot for a day or more, this speeds the settling and makes the oil easier to filter as it is thinner. You will likely have two heating elements, one top and one bottom, you can remove the top element and install a temp gauge. You will have three fittings on top, in, out and vent, be sure to remove the zink anode from the inlet or it will turn to goo in the VO.

The next morning or 4 hours after allowing the oil to settle I drain off about 4 gallons into a bucket (which gets poured back into the first filtration barrel) and take a sample with a test tube. I heat a pan until the oil I wiped on the surface begins to smoke and dump in about a teaspoon of oil, if I do not get bubbles I am good to go, if I do I drain another 4 gallons and retest, often the first will fail but rarely the second.

I then cycle the oil through the bag filter attached to the still about 5 or 6 times, sometimes I forget and leave it cycling for hours. In the end I pump it through the filter and into a tote fitted with a metered pump and nozzle. If I am going to store it for any time, I put it into blue or brown food grade plastic barrels and I fill the head of the barrel with Argon from my TIG rig and screw the cap on tightly and they go into my basement or the back corner of my garage.

By using a water heater we get a free or inexpensive tank with a round bottom, not a conical tank but close, it has fittings already there, a heating element, is designed for liquids, is insulated and is already lined to prevent contact with reactive metals – what else could you ask for! The heater I have is made by Rheem (Rheem Australia Water Heaters... Install a Rheem) and was sitting on the road outside a remodeling progress, the owners had gone to gas.

Cone bottom plastic tanks are available like his one



but they are difficult to heat and you have to install bulkhead fittings in the plastic which is not easily done. I have 4 or 5 of these and am thinking about making the oil cascade from one to the other before putting it into the still, this way I can drain any sediment from each tank easily and the oil will have settled cold for some time before being processed. Honestly if I did not have the tanks, I would not bother as they are expensive.

You can make a cone bottom tank using this page about making a biodiesel reactor, the advantage of a cone tank is that you can clean it simply by draining it and all the gunk comes out without the need to crawl into the damn thing with a rag.

The whole process is simple heating and settling but with the still one pump can be used to fill the still, filter the oil and even pump it into a vehicle and once the oil gets sucked into the still, you do not have to handle it making the whole process much cleaner and less likely to attract rodents or nosey neighbors.

Vacuum.

Vacuum dewatering is an interesting concept although I abandoned it after playing with it, don’t get me wrong, it works, the problem is that it removes just the water and leaves behind any water soluble contaminants that are removed with the water through heating and settling. The theory is this, the lower the atmospheric pressure, the lower the temp at which water boils. If you have a glass ball half filled with water and the void in the ball is a vacuum, the water will boil with the ball just sitting in your hand. That is how those nifty antique bubbling Christmas tree lights worked. Using this theory you can connect an old refrigeration compressor to the water tank (Frybrid Still) and suck the tank to 29” of mercury and all 80 gallons should be boiled off in less than 20 minutes. You can play with this using a simple hand held vacuum pump like a Mighty-vac or you can build one with the compressor from an old refrigerator. I dropped it because the process simply concentrates water soluble contaminants in the oil rather than using the water to carry away the acids, salts and other nasties.

A good application for Vacuum is a sucker tank. A sucker tank is a simple tank off a compressor, a water heater, or a water system pressure tank, you put it in the back of your truck and connect it via a valve to the vacuum pump on your engine (T off the brake booster is common). Open the valve and drive for about 3 blocks and the tank should be down to 15 to 20 inches of mercury. Close the valve and find a big barrel of oil someplace, on the bottom of the sucker tank you have welded a bung and connected a large ball valve to it and about 30’ of hot tub hose. You put the hot tub hose in the drum of oil and open the ball valve at the tank and Sssssssllllluuuuurrrrrpppppppp you suck up the whole barrel in about 2 minutes. When you get home you put the bottom tube into a barrel next to the truck and open the ball valve again but this time you connect a line from your shop air compressor to another fitting on the tank and blow the oil out of your sucker into the barrel using pressure.

[Nuddy Senior Member Find all posts View Profile Close Nuddy]

Re: Vessel for drying

Once in the still I turn on the power and typically it takes about 3 or 4 hours to bring the oil in the still to 140F +/-, this is not done to boil the water off if that were possible it would have already happened in the fryer. The water we are dealing with is filled with water soluble salts, fats and acids and these change the boiling point of the water and act as emulsifiers keeping the water in suspension. By heating the oil we lower its viscosity and we get all the atoms vibrating , this allows the water which is heavier than the oil to agglomerate and the small droplets begin to form larger droplets and they drop to the bottom. We turn off the heating element to stop any convective currents in the still that would carry the water rich oil back upward and allow it to settle for several hours or overnight.

So now we have an explanation why the water is not boiled off in the fryer, thanks for that, it has been puzzling me for some time.
140F = 60C so not very hot. I imagine a black drum left in the sun in summer would get at least that hot. All it is doing then is accelerating the settling. Overnight settling and cooling from 60C, is that any better than several weeks settling at 20 - 30C? Presumably over several weeks settling "the water which is filled with water soluble salts, fats and acids" and "which is heavier than the oil" will "agglomerate to form larger droplets and drop to the bottom" just as well as overnight settling and cooling from 60C.
Then having removed all of the water soluble salts, fats and acids by settling, any remaining suspended (dissolved?) water can be removed by the Dave Jones method.
Then storage without contact with (humid) air should preserve the clean, dry, non-polymersied oil until it goes into the vehicle tank, where it is again exposed to humid air and possibly bare steel. Perhaps we should be using bladder tanks in our vehicles?

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: Vessel for drying

Would there be any advantage in adding water to the oil to take out water soluble salts, especially with oil which is very dry to start with?
This would take out any soluble salts and the oil could then be dried to remove any remaining water.

Regards,
Tony

[Nuddy Senior Member Find all posts View Profile Close Nuddy]

Re: Vessel for drying

Would there be any advantage in adding water to the oil to take out water soluble salts, especially with oil which is very dry to start with?
This would take out any soluble salts and the oil could then be dried to remove any remaining water.

Regards,
Tony

Isn't that what they do with biodiesel, 'washing'?

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: Vessel for drying

Nuddy,
Washing for biodiesel is to remove the byproduct and any residual methanol from the biodiesel. Well settled or methanol removed biodiesel is supposedly just as good as washed biodiesel.

WVO does not have the same issues as Biodiesel.
What effect would "washing" WVO have, other than to increase the time and energy taken in processing the WVO?
Are "salts" and issue with WVO?
What else would be removed by "washing" the WVO?
Would it work as well in our cars, if washed (and dried)?

Regards,
Tony

[Johnnojack Senior Member Find all posts View Profile Close Johnnojack]

Re: Vessel for drying

Nuddy,
Washing for biodiesel is to remove the byproduct and any residual methanol from the biodiesel. Well settled or methanol removed biodiesel is supposedly just as good as washed biodiesel.

WVO does not have the same issues as Biodiesel.
What effect would "washing" WVO have, other than to increase the time and energy taken in processing the WVO?
Are "salts" and issue with WVO?
What else would be removed by "washing" the WVO?
Would it work as well in our cars, if washed (and dried)?

Regards,
Tony

Tony and Paul, I used to wash my oil, not sure what it got out but the water was brown, smelt like cigarette ash and had a low pH (acid). I dont do it any more as my upsettling system is turning out very clean oil thank you.

[cgoodwin Junior Member Find all posts View Profile Close cgoodwin]

Re: Vessel for drying

So now we have an explanation why the water is not boiled off in the fryer, thanks for that, it has been puzzling me for some time.
140F = 60C so not very hot. I imagine a black drum left in the sun in summer would get at least that hot. All it is doing then is accelerating the settling. Overnight settling and cooling from 60C, is that any better than several weeks settling at 20 - 30C? Presumably over several weeks settling "the water which is filled with water soluble salts, fats and acids" and "which is heavier than the oil" will "agglomerate to form larger droplets and drop to the bottom" just as well as overnight settling and cooling from 60C.
Then having removed all of the water soluble salts, fats and acids by settling, any remaining suspended (dissolved?) water can be removed by the Dave Jones method.
Then storage without contact with (humid) air should preserve the clean, dry, non-polymersied oil until it goes into the vehicle tank, where it is again exposed to humid air and possibly bare steel. Perhaps we should be using bladder tanks in our vehicles?

In filtration time is your friend although we are also dealing with other things here, namely the contaminants in the oil which carry water and other nastie gunk like emulsifiers. The best bet is to remove the large particulate matter right away, then settle the oil to get the water to drop out. I prefer to do this as quickly as possible, so I heat and allow to settle overnight rather than allowing the oil to sit for extended periods with water and the associated contaminants in it.

I lived for many years in the desert of Mexico, often 40C+ ambient temps and I had no water heater, just a 400 Liter black plastic tank on the roof and the water was hot. I would think that a large black conical bottom tank set out in the sun would do the same thing with ease.

Water washing has been shown to clean the oil well and is particularly helpful in removing salts and Lye which is commonly used in "Fryer Boil Out" cleaners. If you get oil from a place that smells like soap and is kind of milky, they may be using "Boil out" and it can destroy injectors in very sort order, several VO users int eh US have had to replace complete sets of expensive Powerstroke injectors due to "Boil out". Of course you have now introduced water again to the oil and will need to remove it via heat and settle methods.

Many here have played with centrifuge dewatering and filtration, I personally feel it is over complicated and has factors inherant in the process that are known accellerants in the process of oxidative polymerization of vegetable oils, namely the exposure to reactive metals, intimate exposure to 02 and the requirement of heating the oil for extended periods.

All this said, I know people who simply allow the oil to settle in cubies for months at a time, then suck the cleanest oil from the top of each cubie and pour the remnants together into a cubie for further settling and have had very good results. Of course this all dpened on the type and quality of oil you have collected.

I did some experiments several years ago where I took ambient temp oil (22C) and mixed in 3% unleaded gasoline by volume. I found that overnight a layer of milky fats and contaminants would form on the bottom of the jar and the oil on the top was very clear and clean. I processed several hundred gallons of oil using this method before I had to stop - The fire department inspector was not keen on the 55 gallon drums of VO mixed with gasoline sitting in my shop.

[Nuddy Senior Member Find all posts View Profile Close Nuddy]

Re: Vessel for drying

Tony and Paul, I used to wash my oil, not sure what it got out but the water was brown, smelt like cigarette ash and had a low pH (acid). I dont do it any more as my upsettling system is turning out very clean oil thank you.

So I guess it was removing acid and that must be beneficial. I imagine the upsettling system would be achieving the same.
How does your clean oil from upsettling go on the HPT? Does it need drying.

[Jeffrey S. Brooks Banned Find all posts View Profile Close Jeffrey S. Brooks]

Re: Vessel for drying

I did some experiments several years ago where I took ambient temp oil (22C) and mixed in 3% unleaded gasoline by volume. I found that overnight a layer of milky fats and contaminants would form on the bottom of the jar and the oil on the top was very clear and clean. I processed several hundred gallons of oil using this method before I had to stop - The fire department inspector was not keen on the 55 gallon drums of VO mixed with gasoline sitting in my shop.

Hello, I very much enjoyed reading cgoodwin's description of his Frybrid still. I also use a water heater as a processing tank for my WVO, and find it most effective. Since US water heaters are built to handle 100 PSI (6.6bar) I pressurize it and move my oil through my filtering manifold via pneumatic pumping at about 20 PSI (1.3bar). The advantage of this pumping method is the dirty WVO does not pass through the impeller of a pump, which would otherwise act as a blender to churn the sediments back into the oil. This aids in sediment and water dropping out as it passes through my processing system with nearly zero turbulence.

I agree with Tony, one can easily get a drum up to 140F (60c) or more using a primitive solar collector. I did that quite easily in the California desert near Blythe, where I just put my drums on top of some scrap 3/4” plywood scraps and put a clear plastic “contractor” garbage bag over my 55-gallon drums of settling oil and they got up to 150F by noon in the winter.

Links removed by moderator

I enjoyed reading about cgoodwin's de-watering methods as well. I too have found water precipitates out of WVO when gasoline is added to it, which is yet another good reason to add gasoline (petrol) to one’s WVO. And, like Dave, I too find a “small amount of petrol aids combustion greatly.”

On the veggie_fuel_blennders forum you will find 14 different methods of de-watering described including the gasoline (petrol) method at the URLs below:

Dewatering
Yahoo! Groups
Dewatering with fuel blending:
Yahoo! Groups
vegetableoildiesel.co.uk - Dewatering with fuel blending - Powered by XMB

Note to Dave:
While I am sure you were well meaning, the hot pan test (HPT) with WVO that has some gasoline added to it would be pretty dangerous and unadvisable. But, I could see coming up with some other method to determine just how dry WVO gets when gasoline (petrol) is added to it. And, if a safe water content test could be found, then one could determine just how much gasoline (petrol) one needs to add to thoroughly de-water WVO.

[Socrates Donating Member Find all posts View Profile Close Socrates]

Re: Vessel for drying

I've asked this question before and Dave said something about it - Has anyone had success with this stuff. Vegie Cars - Filter Powder

If it works then it has to be the easiest thing going. Simply add powder and wait. All nasties and water go to te bottom leaving beautiful honey coloured oil ready to go on top.

No mucking around.

If no one has tried it on the forum then I might buy some and be the guinea pig.

[Johnnojack Senior Member Find all posts View Profile Close Johnnojack]

Re: Vessel for drying

So I guess it was removing acid and that must be beneficial. I imagine the upsettling system would be achieving the same.
How does your clean oil from upsettling go on the HPT? Does it need drying.

Maybe it was removing acid I don't know. However I would like to know if the oil I now process has "acid" in it? It does not compute that it would as acid is a property of aqueous solutions not oil. (Seeking clarification from someone who knows their chemistry better).
Re HPT my last 300 litres of oil has passed 100% The heatwave has helped and I can process oil faster as a result. Am even getting black sediment out of the first drum. The 3rd drum produces oil as clean looking as new engine oil. From there it goes into a 4th drum through a 5mic filter bag and from there is filtered through two 5micron house filters and looks the same, nice enough to eat

Jeffrey Brooks while your idea of standing a drum of oil in the sun works to heat it up I found that subsequent cooloing at night sets up convection currents which undo any settling which may have happened from the heat. I don't do it that way anymore but instead solar heat insulated drums indirectly.

[Nuddy Senior Member Find all posts View Profile Close Nuddy]

Re: Vessel for drying

Maybe it was removing acid I don't know. However I would like to know if the oil I now process has "acid" in it? It does not compute that it would as acid is a property of aqueous solutions not oil. (Seeking clarification from someone who knows their chemistry better).

If you are adding neutral water and then removing acidic water then you must be removing acid.
I too would like clarification on the acid issue but my thought is that acid is only acid in the presence of water. Thus if there is no water, although the other component of the acid may still be present it would be harmless without the water, just sitting there waiting for some water to turn it back into acid.
If this is the case then the most important thing would be to remove all of the water but surely it would be good to remove the other component of the acid as well so that if some neutral water somehow gets into the oil it would be less harmful than acidic water.
I am thinking that first priority would be to get a good effective drying system working, then wash out the acid, settle and drain, then dry, for the best quality oil.
The drying powder does something similar in that it apparently absorbs the acidic water and settles out - an expensive way to do it though. Oily from Shoalhaven has released the secret of a much cheaper drying powder on another thread. i have had some for over a year but still not tried it out.

[Socrates Donating Member Find all posts View Profile Close Socrates]

Re: Vessel for drying

[cgoodwin Junior Member Find all posts View Profile Close cgoodwin]

Re: Vessel for drying

Did the clean, clear oil on the top pass a HPT after being treated with the ULP?
Passing a HPT to me is NO bubbles at all as distinctly different to some peoples standard of being " only a few " bubbles.
I wouldn't mind treating the oil with the ULP and having it in there, I think a small amount of petrol aids combustion greatly. I just wouldn't want to waste it by loosing it in a subsequent drying process.

Ohhh Noooo. If you add diesel or gasoline the oil will fail the HPT as both fuels have lower vapor points than VO. SO test the oil first, then mix a little.

Gasoline adds cetane and lessens the ignition delay, all studies show that about a 2 degree advance in pump timing aids the burning of VO, the added cetane does this by shortening ignition delay. The local shops in my area save gasoline for me, often someone will put gasoline in a diesel or diesel in a gas car, happens at least 2 or 3 times a year. The subsequent mix is costly for the shop to dispose of so they call me. I add it to my veg tank when I fill up at a rate of about a gallon to every 20 gallons of VO.