Back in 2005 no one really knew why we could filter vegetable oil to 2 microns and a month later plug a 10 micron filter, we were not sure why vegetable oil and biodiesel both caused the formation of deposits on the steel surfaces of the fuel system, no one knew what it was or why it was occurring.

A year later Joe Beatty released “The Beatty Report”, his findings created quite a stir and have subsequently been supported by a great deal of research. Some in the SVO field swore that metals were not reactive, that without water in the fuel this could not happen and went so far as to attack Mr. Beatty himself. Subsequent research has come to light showing that every statement he made was completely accurate and thanks to his work we all learned a great deal about how and why vegetable polymerizes.

In short, vegetable oil breaks down through a process known as oxidative polymerization, oxygen attacks the double bonds of the triglyceride molecule and begins to break apart and twist the molecule until it can form long chain polymers with other molecules and it is these polymers that eventually link together forming a coating on particular metals and/or filter media. The formation of these polymers on the filter plugs it, the formation of polymers on steel interferes with tolerance critical parts in the injection pump and injectors can cause moving parts to seize or break and can accelerate the formation of rust on those parts.

All vegetable oil will polymerize, the less saturated the oil the faster it will polymerize. New vegetable oils are high in natural antioxidants which preserve them, however as the oil is used these antioxidants are used up leaving the oil unprotected. In the first stages of oxidation the molecule begin to degrade and peroxides are formed, these peroxides give food cooked in the oil a bitter or off flavor and the restaurant disposes on of oil, so by the time we get it the oil has already begun to oxidize, in addition it is full of contaminants; water, salts and acids from the food that was cooked in it, all these things contribute to further degrade the oil. Certain other factors accelerate polymerization; exposure to oxygen, exposure to heat, exposure to reactive metals and exposure to sunlight. Limiting any or all of these will radically extend the life of your oil.

Frybrid’s Veg-stable offers another method which should be used in conjunction with limiting the known factors listed above, it offers you the ability to add an antioxidant to the oil extending the life of the oil until the process of oxidation had used up the antioxidant, this can extend the usable life of the oil two to three times in a harsh environment and nearly indefinitely if the other factors are limited as well.

Even with the use of Frybrid Veg-stable it is advisable to have a vegetable oil system that washes the fuel system components with diesel fuel before shut down, the diesel purge cycle should flush the vegetable oil back to the vegetable oil tank and bathe the fuel system components in antioxidant rich diesel preventing the formation of vegetable oil polymers while the vehicle is not being driven, the fuel system have no copper present and that the in-tank heat exchanger should heat only the fuel being drawn out of the tank and merely warm the rest of the tank so that the vegetable oil can easily be drawn up.

Collected vegetable oil should be filtered and dewatered as soon as possible after collection, treated with Veg-stable and stored in a cool place in non-reactive containers with as little head (air space) as possible.

Recommended mix is 1.5oz per 50 gallons resulting in a 300ppm level