Preparing Used Cooking Oil

Just filter the oil and heat it to > 80^oC to evaporate away water.

Heating the oil costs energy! I process at ambient temperature and gravity filter. Heating solubilizes things that can solidify and precipitate upon cooling(free fatty acids, saturated fats). Pumping thru filters often forces stuff thru the filter that later settles out. My tank has a valve a couple inches off the bottom and allows dregs (including water) to settle. I also have a filter screen in the out valve. Every year or so I drain the tank for cleaning.

If I may, I'd like to elaborate a little on Mr. Vader's comment. Filtering is vital!First you need a coarse filter to remove the french fries (window screen or a nylon stocking work well).I then go to progressively finer filters using nylon filter bags like used in chemical plants. I buy them by the box of 50. They can be scraped out and reused if necessary.I go thru 100, 25 and 5 micron bags. Some sort of silt forms upon standing (air oxidation products?) that is removed by a 1 micron bag . I then pass thru another 1 micron bag to my storage tank. I have a 100 micron piece of filter stuffed into the outlet to catch any debris in the tank. Water will settle to the bottom, so I have my tank tilted away from the outlet valve. My diesel car has a final fuel filter before the injectors. I change it whenever the engine gets sluggish (2000-3000 miles). I process 10-12 gal a week, usually. But last Thanksgiving, I got 100 gal from a Boy Scout troop that Cajun-fried 108 turkeys for a fund-raiser. Had to work over-time that month! :-)

The basic oil lamp should work on any cooking oil! If you want to clarify oil then the basic system is what you need - strain it to remove any fish and chips - pour boiling water over it - stir- wait for it to cool - decant.

Not sure about diesel that generally means treating the original Triglyceride with Sodium Methoxide ( caustic soda and methyl alcohol) to give esters.

If you filter it well and run it at ambient temperature, a diesel will operate on it, I think.

Oil in the pure state tends to gel at low temperatures, even 4C can gel some cooking oils. So it can not run a truck if it gets cold.

Might smoke a little. Removing the glycerol reduces smoke

Burning in a shop stove? Made for what fuel? Kerosine? fuel oil?

there may not be enough volatility in used cooking oil that has not been transesterified to remove the glycerol for it to replace kerosine or fuel oil well.

It would be good for making smoke screens off Scapa Flow during maneuvers...

You cannot remove the glycerine from the cooking oil without breaking the triglyerides by chemical reaction - they are part of the molecule.

Of course, that is removing the glycerol, is it not?

Quote

"in used cooking oil that has not been transesterified to remove the glycerol for it to replace kerosine or fuel oil well"

there cannot be any glycerol present until the oil is broken into esters & glycerol ! Once it has been split it is no longer cooking oil!

since I am an alkyd chemist, retired, I am well aware of the fact that a polyhydric alcohol, (in this case glycerol) can be combined with fatty acids to make an ester, which is the plan oil we speak of. They call this esterification. It is analogous to the neutralization of acids and bases that takes place in aqueous media

When I say the glycerol must be removed, to release the acid component (fatty acid), and I am quite correct.

They call it transesterfication, a changing of partners to remove the glycerol.

http://en.wikipedia.org/wiki/Biodiesel

Please go through www.servalsgroup.blogspot.com. You will find a posting on a hybrid plant oil stove. This may be one of the solutions possible for you.

Rajan

Back during the "Carter oil crisis", my brother assembled a diesel van (Continental "litre-engine") with dual controls which he used to drive 10,000 km non-stop, non-refueled, on non-petroleum fuel (a big loop around the US from CA to NY and back), his "mobius trip." It was in the Guiness Book of Records for one year. He used raw cotton seed oil, which is often used as cooking oil. The only difficulty was a kind of waxy precipitate at near-freezing temperatures. Heating the fuel filter fixed that. He wanted to show that we could do without so much Arab oil. The motoring press ignored it, which is logical, considering that some of their major advertisers are oil companies. Many will say that cooking oil will coke up the injectors, but his showed no signs of that.

I have almost 2 years and 25000 miles on my '84 diesel Benz running used cooking oil. I love it! Saves me a ton of money. Its my way of thumbing my nose at those camel jockeys at OPEC. They don't like us anyway- just our money!

A market has now appeared and small operators sell their used on on annual bids. Large commercial oil users process their own used oil into biodiesel. This reduces the gain many could make from the home processing of used oil.

There is no doubt that removing the glycerol component and leaving long chain hydrocarbons turns cooking oil into a resonable facsimile of kerosene diesel fuel; it meets the specifications for diesel and is sulfur free. However, diesels will run well enough on the heavier-molecular-weight vegetable oil, or even, I've been told, on liquified animal fats, like butter or whale oil. Veggie oil drives the nanny-state bureaucrats nuts, as it doesn't meet the specs for diesel fuel, even though it does not pollute more than the "good stuff."

I am reminded of a journal article, published in the 50's via time travel from the distant future. It noted that primitive man had evidently mined coal, perhaps for blackening the face, and, since nuclear fuels were becoming scarce, after centuries of use, it might be time to see if alternate energy sources could be found. Oxidizing carbon poduces heat, and perhaps coal could provide the carbon. It noted that coal is easy to machine into "fuel elements" and went on to discus how, with sufficient research, a reactor might be designed to replace the uranium reactors. Spent fuel (ash) disposal, of course, would be a serious problem. Sometimes biofuel advocates sound like the future coal advocates. As any fire department can tell you, cooking oil will burn without transesterification.

Heat the oil to about 180°F and the impurities will be pushed to the bottom then skim off or have a valve to remove the upper third of oil from the tank.

Push this through a 5 micron filter and violà

You must heat the oil in the fuel tank too for best performance.

Review previous threads on topic:

http://cr4.globalspec.com/thread/39150/fats-in-bio

http://cr4.globalspec.com/thread/4759/Vegetable-Oil-and-Home-Heating

http://cr4.globalspec.com/thread/29636/Vegetable-Heating-Oil

http://cr4.globalspec.com/thread/9888/Greasecar-experiences