Home page
Our Product RangeUK Bio-power companiesFAQEvents and ActivitiesContact usSite Map
Deeper studyTaxationThe bio-power CharterOur Vision for a bio-power networkChemistry
Invest in saving the planetQuotesLinksDownloadMembers
How to make a simple heat exchangerCan I burn straight vegetable fat in my diesel engine?
How can I know if my engine will run on Straight Vegetable Oil?If my engine runs on SVO, then can I burn WVO?
How to make your own fuel from waste fat
It is possible to run vehicles on waste vegetable fat without going to all this trouble of converting the fuel supply system. Instead of modifying the engine, you can modify the fuel. There is no hard and fast rule about which is the best way. If (like Steve) you like playing about with machinery and can't keep you fingers out of the engine compartment then your game is to modify the fuel delivery system. If (like me) you prefer an easy life, then modify the fuel. This is how we developed the much more sophisticated form of MWVF we sell commercially.
WARNING! This is the first stage to becoming a commercial bio-power agent. Most people who start making their own fuel end up in business!
Find a fat user who uses corn or rape seed oil, and turns over their fat regularly. They should be encouraged to keep their fat clean and not polluted with rainwater. Collect their fat regularly, and if necessary pay them up to 10 p per litre for the fat, to encourage them to change their fat more often. This will provide you with more fat and at a better quality, and it will benefit the fat user because they will get cleaner fat in the food. Remember that this man is going to help you make or save a lot of money so ensure that everyone is happy.
Pour the fat through a sieve and into a 45 gallon steel drum with taps down the side. A satellite dish makes a good sieve. The purpose of the sieve is simply to remove chips, maggots, onion skins and any other solid debris. Keep the drum covered to prevent rainwater getting into the fat. Fill the drum and let it settle for about a week, then draw off any water from the bottom, and siphon off the clean fat from the top.
Put this fat into a large preserving pan and heat on the stove to about 50 to 60 degrees. Slowly stir the fat and you may notice what looks like frog spawn on the bottom. This is water that has been pulled out of the fat. Have ready a beer fermenting bucket with a tight fitting lid, or any suitable clean re-sealable plastic bucket. Prime the bucket with solvent. You will need about 5% of the volume of the bucket when full. Do not use kerosene - even though this will work fine, as it is a fossil fuel which is marked by HM Customs and Excise. Industrial white spirit or turps substitute will serve well. Later you can learn how to use bi-ethanol.
Make a simple wooden bridge with a hole in it to take a kitchen sieve, so the sieve can be placed over the top of the bucket. Put half a 'Jay Cloth' in the sieve, or a 'Jay Cloth' folded in half to get double the filtration. Pour the heated fat through the sieve. This will remove any particles down to about 10 micron. The Jay Cloth can be washed after use in household washing soap.
Close the bucket and put it in a place to stand for three to four weeks. This allows any double bonded fats to precipitate. It is a cheap and simple way to prepare your fat for use. If you do not wait for the fat to mature the you risk clogging the fuel filter in your vehicle, and starving the engine of fuel. When the fat is ready, carefully open the lid and using a plastic pipe siphon off the fuel from the top until you reach the bottom. Then check to see how much sediment there is at the bottom. You can throw any sediment into the first settlement tank and it will settle out again. The point at which you separate the fat is the tax point. I put this fuel into a different type of container so I know what fuel has been recorded as tax paid.
There is no hard and fast rule about what sort of solvent works best of at what proportion. You may need to experiment a bit to see how this fuel behaves in your engine. I prefer a fuel that is a fraction grumpy on starting., but runs well once warmed up.
Eventually you will need to clear the build up of opaque fats from the main separator tank. This is run off from the lowest tap, and can be stored in buckets. I then separate the clear fats from this material using a special separator made by drilling a few holes in the bottom of a bucket, and placing a cylindrical wire frame inside to support a 'Boots' wine making bag. This fits exactly over the size of bucket we use. Place the perforated bucket over a collecting bucket. Pour the fat into the bag and allow it to settle. Keep pouring the collected fats back into the top bag until the filter bag is filled with the fat forming a coating. The filtration is not achieved so much by the bag as the fat itself. Then allow the whole to drain slowly like separating the whey from the curds when making cheese. The bottom bucket will fill with quite clear fat suitable for making fuel, and the top bucket will get more and more thick fat. Eventually you can scrape out the thick fat. This can be used as heating fuel if you have a fire, or suitable burner, or it can be used to run a large generator.
(I hope we will be able to add some pictures of the simple process as soon as we get the digital images).
How to make your own heat exchanger
Return to main bio-power site index
John Nicholson
3rd January 2002 October 2002 June 2007
I hope you found the information on this site useful.
Do not hesitate to contact us if you have any further questions.