He would collect waste cooking oil (canola typically) from the local chip waggons in Arnprior outside of Ottawa and process it in to fuel for his diesel pick-up truck. The process which he demonstrated for the audience that night was very simple.
- Filter the used oil - he suggested ladies' pantyhose
- Mix Lye (aka. NaOH) and Methanol (aka. Wood Alcohol) in solution (100g of Lye, 1/4 oil volume of Methanol, I'm skipping a big part here so don't use this recipe)
- Heat oil to 60C
- Mix "MethOxide" solution with Oil and continue mixing
- Wait for the mixture to separate into (top to bottom)
- a thin water/soap interface
- Glycerine / Glycol
BioDiesel is not Veggie Oil. It's made from vegetable oil, but it's entirely different.
The lower viscosity is the prime difference - this is why they sell BioDiesel not VeggieOil at the pumps. Thick veggie oil will kill your injector pump. BioDiesel is thin - your injector pump doesn't know the difference.
If you've ever made soap at home or in school you'll notice this almost identical. But instead of adding water, you add Methanol. Making soap bonds a water and oil molecule using Lye. This reaction bond oil (triglyceride) to the Methane ion after the lye is used to remove the glycerines from the oil.
The only major cost is the methanol - typically $1CAD / Litre. So little lye is used that it's a non factor ($30CAD/kg). Oh, and methanol is highly flammable, odourless, and carcinogenic. Nasty stuff. The cooking oil is free if you find the right restaurant - they pay for a special service to dispose of the oil. They typically restaurants will go through 60L per week - more if they're picky about flavour or get a lot of fried-food business.
So I went about to try to make some myself. It wasn't a disaster, but it wasn't a success. Using an electric hot water tank element found at any hardware store I cooked up some oil. A pub in Bell's Corners called The Cock & Bull had a head chef nice enough to let me have 20L for my first experiment. I bought methanol from Canadian Tire (labelled as cooking stove fuel) and my good friend M had got himself a 1kg pail of lye. Cooked up the oil in a HDPE plastic pail, added the methoxide, and poured it into a glass carboy used for making wine.
There are cleaner ways to make biodiesel in much larger quantities for the run-of-the-mill homebrewer. The hot water tank design seems to be the most popular and sensible.
But this is the point were I learned that making fuel for my car is tricky for a few reasons:
- Methanol is dangerous
- I'd need by 205L (50gal) barrels at a time to keep costs down
- Cost per litre of fuel is generally $0.30CAD after accounting for bulk purchase of methanol
- It makes a f'ing mess
- If I mess this up, I could hurt my car and need to pump out my fuel tank
- I have no real way of knowing if I messed this up until it's too late
I started to look what it would take to run on veggie oil - no biodiesel - just pure filtered veggie oil. I found happiness in simplicity and cost. More on that later.
Oh, and I did get a good batch of biodiesel made. Using fresh oil I bought at the grocery store I was able to make 1.5L of pretty biodiesel. Notice that I removed the glycol from the bottom of the batch except for a little bit more water and glycol at the bottom of the jar.
As messy as it was - I tried it and learned what I am not willing to tolerate in my adventure of mine.
Next - how to make a 2001 diesel VW Jetta run on used cooking oil.