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High Purity Biodiesel and Glycerine via Wiped Film Evaporation |
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High Purity Biodiesel and Glycerine via Wiped Film Evaporation
By Paul Belleisle PE, Manager Engineered Systems, Pfaudler, Inc.
Methyl ester (AKA biodiesel) is produced from various fat sources (plant oils, tallow) by reacting methanol with a fat to displace the glycerine in the presence of catalyst. The methy ester product may contain unreacted oil and methanol, catalyst and water. A high purity methyl ester can be produced via distillation utilizing a 2-step process:Step 1: The methanol and water are stripped off.Step 2: The biodiesel is distilled from the unreacted oil and catalyst under vacuum. Typically a wiped film evaporator is utilized for Step 2 because of the “short path” distance the methyl ester vapor travels from the evaporation surface to the condensing surface. This “short path” enables the vaporization to occur effectively under vacuum at greatly reduced temperatures. (Note: Download the Pfaudler Biodiesel Data Sheet for this application.) Likewise, the crude gylcerine by-product can be distilled from salts and other dissolved solids in a wiped film evaporator to produce USP Grade glycerine. In this case the evaporators ability to discharge the viscous bottoms salt slurry is critical. Pfaudler, Inc. has been producing wiped film evaporators and evaporation systems for over 50 years and has significant experience in processing biodiesel and glycerine. Pfaudler has a pilot plant test facility in Rochester, NY where evaporator performance can be demonstrated.
Biodiesel Distillation (647 KB)
High Purity Biodiesel and Glycerine via Wiped Film Evaporation (15 KB) |
