I've seen a lot of different methods for cleaning biodiesel over the years. Some were pretty strange. Until now, I've kept my preference for water washing as the best way to clean biodiesel. Sawdust changes that. It's a cheap media available everywhere, and it actually works to remove soap and glycerin.

The only problem I see with the system is methanol. It does not remove the methanol. If you don't remove the methanol then the flashpoint fails to meet the ASTM standards. There has been a debate for years about leaving the methanol in the fuel. Some think it adds value to the fuel, others think it ads risk of engine damage.

The majority of sawdust users are removing the methanol before passing the biodiesel through the sawdust. A minority are using the biodiesel with the methanol still in the fuel. I would like to see a method of removing the methanol that is simple and safe.