USE OF RESIDUAL BIODIESEL FROM RAW GLYCERIN FROM COMMERCIAL BIODIESEL PRODUCTION

The purpose of this work was the removal of byproducts such as free fatty acids and glycerides present in the crude glycerol. The free fatty acids and the glycerides were separated chemically by hydrolysis with phosphoric acid and mechanically with a separatory funnel. The products separated from the crude glycerin were esterified with an alcoholic solution of dimethyl sulfate and subsequently transesterified with a alcoholic solution of potassium hydroxide to obtain the biodiesel (monoalkyl ester). The biodiesel was purified with Montmorilonite clay. It was analyzed by the acid value test and by solubility in methanol. The volume percent of biodiesel varied between 60% and 80% of the original crude glycerol. Finally the biodiesel (4 liters) was tested as a fuel in a pickup truck.