Artisan’s FFA Process

In this process, high FFA content crude feedstock is pumped through a feed/bottoms economizer and a trim heater to preheat the feed, while cooling the stripped product oil (bottoms) to its desired temperature. The preheated feed enters a vapor/liquid separator, operating under vacuum where a portion of the FFA as well as any moisture present is flashed off. The remaining liquid falls by gravity into the Artisan Rototherm® mechanically aided thin film evaporator where the centrifugal force generated by the spinning rotor maintains a thin film of material on the heated wall, evaporating essentially all the remaining FFA. The product discharges by gravity from the Rototherm into an insulated bottoms accumulator, from which it is pumped through the feed/bottoms economizer before entering the biodiesel process.

The Rototherm is designed with a counter–current liquid/vapor flow configuration to maximize mass transfer and minimize entrainment. Turbulence created by the rotor blades constantly renews the film, aiding in both heat and mass transfer, enabling nearly complete removal of the FFA, while preserving the quality of the stripped oil.


Heat to the Rototherm is provided by heat transfer oil. Nitrogen at very low rates is continuously sparged into the evaporator to aid in stripping. The FFA vapor from the Rototherm combines with the pre–flashed vapor, passes through a mesh entrainment separator in the vapor/liquid separator and enters the condensing system.