Making Biodiesel – World Famous Dr Pepper Technique (Pat Pend)
Posted March 5, 2007on:
The idea for the Dr Pepper Technique came about one day many years ago (it seems) when I was trying to figure out an inexpensive way of making a few test batches of biodiesel. WARNING
I will assume that if you are reading this for the information then you are new to Biodiesel making, so just a few words of caution:
THESE ARE DANGEROUS/POISONOUS CHEMICALS
COMMON SENSE MUST BE USED
YOU ARE RESPONSIBLE FOR YOUR ACTIONS AND THE SAFETY OF YOURSELF AND EVERYONE/EVERYTHING AROUND YOU
METHANOL IS A POISON WHICH CAN BE ABSORBED THROUGH YOUR SKIN, BY INHILATION, OR CONSUMPTION
METHANOL CAN CAUSE BLINDNESS AND DEATH
METHANOL IS AS FLAMMABLE AS GASOLINE/PETROL
CARTRIDGE RESPIRATORS DO NOT WORK WITH METHANOL
Sodium hydroxide (Caustic soda, NaOH, lye) can cause severe burns and death.
Long-sleeve shirt, full shoes and trousers are recommended, no shorts or sandals.
Wear chemical proof gloves, apron, and eye protection.
Do NOT inhale any vapors.
Always have running water available to wash off any splashes.Now that I have managed to scare you, just realize that Methanol is the fuel used in most model airplanes. In the
USA methanol is available in small quantities as HEET brand fuel line antifreeze (Yellow bottle)
Lye is an every-day drain cleaner.
Both are freely available in most large shopping centers.MATERIALS REQUIRED
1 liter oil- new or used
NaOH (lye / caustic soda), at least 6g.
–Used as a drain cleaner and can often be found next to the Drano.
Methanol at least 250ml.
–HEETｮ Gas- Line Antifreeze in the yellow bottle is methanol and readily available in most auto supply stores in the
1- 2 liter (1.9 in US) Dr Pepper Bottle in sound condition with top and dry inside.
1- Measuring cup to measure out 250ml methanol
1- scale to measure 6g NaOH
1- teaspoon measure metric or imperial
1- container to mix the methanol and NaOH in which makes methoxide.
1- FunnelTHE TECHNIQUEOIL PREPERATION
if using waste oil, take one liter and heat to at least 120 deg c to remove all water.
If water is present the oil will spit and pop and carry on.
If there is a lot of water this could get very violent, so be careful.Once the water is gone (Oil becomes calm and there is no more spitting and popping) let the oil cool.If you are using new oil from the bottle it should have no water in it, so in this case just heat to 55deg c when you are ready to mix.MAKING THE METHOXIDE
METHOXIDE IS A POISON! DO NOT BREATH VAPORS. WASH OFF ANY SPLASHES.
DO NOT MIX THE METHOXIDE IN A PLASTIC SOFT DRINK BOTTLE AS THE NaOH ATTACKS THE PLASTIC AND YOU WILL QUICKLY BE SHAKING A BOTTLE FULL OF HOLES WITH METHOXIDE GOING EVERYWHERE.While the oil is cooling mix your methanol and NaOH (lye) to form the methoxide. Use 250ml of methanol. This is more methanol than most people use but will help insure a successful first batch.
If you are using new oil this will require 4g (about half a Teaspoon) NaOH.
For used oil, you should do a titration to determine the correct amount of NaOH to use. However, if you do not have the materials to do a titration, just use 6g- 7g NaOH as this amount almost always works. If you do not have a scale, this is about 1 level teaspoon measure (metric or imperial).NaOH and Methanol do not readily mix so if you are doing it by hand a bit of time and patience is required. Don’t sniff the fumes. CARTRIDGE RESPIRATORS DO NOT WORK WITH METHANOLFor quickest mixing, start with the methanol at JUST body temp (not warm). As you mix, the temp will increase substantially. This is normal. Make sure ALL the NaOH (lye) is dissolved. This may take 10 minutes or more.Hand mixing can be accomplished using a spoon to stir/crush the NaOH granules; OR placing methanol/NaOH in a glass bottle with a top and shaking/ swirling until ALL NaOH is dissolved.After ALL the NaOH has dissolved, top up to 250ml with fresh methanol, as there may be some evaporation during mixing.MAKING THE BIODIESEL!
When the Oil’s temp has dropped to 60 deg c or less, using a funnel, pour the liter of oil into a DRY 2 liter Dr Pepper bottle (in a pinch any other brand of bottle will do).
Take the mixture of methanol/NaOH (commonly called methoxide on this forum) and pour on top of the oil using the same funnel.
Screw the top down TIGHT onto the bottle.
Shake vigorously for about ten seconds / 40 good shakes.
NO appreciable pressure is generated during this mixing.Now place the bottle on a table and observe the oil change color from chocolate milk to a rich darker brown.
Then, as if by magic, within 10 minutes the by-product (commonly referred to as glycerin on this forum) starts to settle out and form an increasing layer on the bottom of the bottle.Within an hour, most of the glycerin will be settled out. This is referred to as separation.
Be sure to notice that you can see a very definite, slowly sinking line towards the top of the Biodiesel as the glycerin slowly settles.You should now have a bottle containing lighter colored biodiesel on top of a layer of darker glycerin. The biodiesel will be very cloudy, and it will take a day or two more for it to clear.
Typically the glycerin layer is about the same or a bit more than the amount of methanol used. If it does not work out come onto the forum and see if anyone can figure out what went wrong.Washing A Small Batch – World Famous Dr Pepper Wash Technique (Pat Pend)
Having just produced your first batch of biodiesel using the World Famous Dr Pepper Technique (Pat Pend) this is an easy nearly foolproof method of washing it.This is a simple nearly foolproof method for washing small test batches of biodiesel and I have often washed a sample of biodiesel in less than an hour using this method.Be aware that unwashed biodiesel contains soap. If you agitate your first few washes hard/violently, there is a real likelihood that the water, soap, and biodiesel will form an emulsion that may take days or weeks to separate.The three important steps in washing are GENTLY GENTLY GENTLY to begin with. THE TECHNIQUE:Wash One:
Pour 1 liter biodiesel into a 2 liter Dr Pepper bottle.
Gently pour about 500ml body temp water into bottle.
Replace non leaky top.
GENTLY rotate bottle end for end for about 30 seconds.
After 30 seconds place bottle upright.
If you have been GENTLE the water and Biodiesel will separate immediately.
You will notice the water is not clear.
Remove top and using your thumb as a stopper, turn bottle upside-down and drain the water using your thumb as a valve.
You have finished wash one.
World Famous Dr
Pour in 500ml water and repeat wash one, except rotate GENTLY for about 1 minute.
Drain as in washes one.
You have finished wash 2.Wash Three:
Again pour in another 500ml water and GENTLY GENTLY GENTLY shake bottle for a minute or so.
When water and biodiesel separate discard water in same fashion as beforeWash Four:
500ml water and a bit more agitation for about 1 min.
After separation of water and biodiesel drain as above
You should now be able shake fairly vigorously.Testing For Completion
Washing is finished when after shaking, water is nearly clear.
Be aware that in your later washes you should be able to shake violently.
The water and oil will take longer to separate because the water forms tiny bubbles in the biodiesel that take time to settle out.Washed biodiesel is VERY CLOUDY, much lighter in color than the original biodiesel and looks terrible. After a day or 2 settling and drying it will clear.Royalties:
Remember, after you have produced in excess of 53,487 liters of biodiesel in any calendar year, using the
Pepper Technique (Pat Pend) Royalties are due.Make check out to Tilly from
Paradise and send to me through your favorite Numbered Swiss Bank Account