As any biodiesel producer knows, feedstock is the most expensive part of the biodiesel production process. Lower cost feedstocks, such as animal fat or used vegetable oil, are frequently of lower quality, containing a higher percentage of free fatty acids (FFAs) that will react with an alkaline catalyst to make soap. This soap must be removed from the biodiesel.
Currently, the most common methods for dealing with free fatty acids tend to be expensive and/or cumbersome. The University of Idaho’s Biodiesel Education Program tested four different additives that have been anecdotally recommended to remove FFAs from oils and fats.
Additives tested:
- Magnesol 600R, a magnesium silicate blend manufactured by the Dallas Group of America
- X-tend, a commercial frying oil purifier manufactured by Selecto Scientific in Suwanee, GA
- Super Bio-Z, a zeolite manufactured by JNS Ranch Company in Rathdrum, ID
- Montmorillonite K-10, a bentonite clay manufactred by Acros Organics in New Jersey
For a detailed two-page summary of the research, please see: http://www.uiweb.uidaho.edu/bioenergy/Adsorbents.pdf
