Hence the second base-stage. For the first stage you'll form a compound out of an acid and an alcohol. No sulfur remains in the biodiesel fuel product. Equipment Ordinary iron and steel implements and containers will corrode. I use a polypropylene plastic reaction vessel.
Stainless steel is also fine.
With stainless steel containers you can use propane heaters. This means you can use the usual 55-gal drum. The process The process is very similar to the one we do already. Filter the used cooking oil first as usual. For a successful reaction the oil must be free of water.