Resumen:
Biodiesel produced from castor oil has attractive properties as this fuel can be produced from renewable energy sources without compromising food supply. A B20 castor biodiesel-diesel blend was used on a diesel engine without any other modification. A field study was conducted on a diesel school bus in the state of Morelos, Mexico, to evaluate fuel efficiency and fuel emissions from diesel and from the B20 castor biodiesel-diesel blend under bus driving conditions on the highway and in the urban area. Refined castor oil was used to produce biodiesel at pilot scale (300 liters) in compliance with the B100 ASTM D6751 standard. The results show the benefits of using castor biodiesel since, when com¬pared to diesel fuel, similar fuel efficiencies and reductions in exhaust emissions were accomplished with the B20 castor biodiesel-diesel blend. This blend represents an environmental-friendly alternative to reduce diesel consumption without threatening the food supply, because castor biodiesel is produced from wild plant oil.