Mini Batches
I started with a 1 liter test batch. Mixed 200 mL (20%) methanol with 6.5 grams of NaOH (lye). After the lye mixed with the methanol I mixed it with 1 liter of Waste Vegetable Oil (WVO).
The reason I picked 6.5 grams of lye instead of tritrating, is that it is what most of the people on the Biodiesel Forums discussion board use. If I had tritrated, I would still make mini batches just to confirm it's readings so I don't make a batch of soap instead of biodiesel. Hence, I took a step out of the loop.
There are three layers in the picture above. With just pure vegetable oil you should only have two layers. The biodiesel layer and a glycerin (darker brown) layer. This and subsequent mini batches were made at a temperature of 70F (22C).
I was concerned about the cream colored layer. I noticed that if I put this bottle in the sun, that after it heated up, it disappeared into the biodiesel layer. I then obtained two layers. After discussing this with the other biodieselers, it was concluded that the cream colored layer is in fact biodiesel made from tallow (animal fats). Tallow goes solid at almost 60F (15C). This mini batch sat over night with the temp going down to 50F (10C).
I decided to make a 4.5 and 5.5 gram of lye to 200 mL methanol mini batches to see if I could reduce the amount of lye. From left to right in the above picture is 4.5, 5.5, 6.5.
What I noticed was that the 4.5 and 5.5 mini batches did not have as much glycerin on the bottom. In fact neither of them came up to the 200 ml level indicating that there was still alcohol in the upper portion, which means these two tests did not go to completion.
So I proceeded to make a 13 liter batch with 84.5 grams of lye and 3 liters of methanol (23% methanol). It separated out into a nice glycerin layer and biodiesel layer. With some solid biodiesel floating around after settling, I decided I would separate this product by filtering. A cheap clear plastic fuel filter became clogged after about a gallon of biodiesel went through it. Then I came up with another filtering method. Strain it through a vacuum cleaner bag as suggested by another Maui biodieseler.
I cut the bottom off a coke bottle and turned it upside down with the spout pointed down, inserted the bag and siphoned my biodiesel out of it's mixing bucket into the bag and let it drip into the larger container as shown above. This was a rather slow process, but the final product came out looking like a winner.
I took the esters from the tallow and scrapped them from the vacuum cleaner bag and put them in another container for future use. Either as summer fuel or as a fuel to heat up future biodiesel batches.
Then I dumped my product into my tank, with about a 20% biodiesel to 80% petrol diesel and fired it up. The car ran like it normally did. After driving a couple of hundred miles, the exhaust didn't really have a distinctive smell but the natural smell of petrol diesel was virtually eliminated.