Viscosity reduction of castor oil esters by the addition of diesel, safflower oil esters and additives

The high viscosity of vegetable oil can be reduced by transesterification with alcohols and converting it into biodiesel. Biodiesel can be used neat or blended with diesel as engine fuel. This study demonstrates that esters of castor oils have a higher viscosity than safflower oil derived esters and the viscosity can be reduced by blending with diesel. The viscosity increased in a non-linear fashion as the percentage of castor esters increased in castor esters diesel blends and in castor esters safflower esters blends. Only slight increases in viscosity were observed for B40 and B60 mixtures with No. 2 diesel. Addition of ten chemical additives in castor esters at the rate of 0.01%, 0.1% and 1.0% showed limited viscosity reduction.

► Esters of castor oil had higher viscosity than safflower oil derived esters.
► The viscosity of esters of castor oil was reduced by blending it with diesel.
► The viscosity increased in a non-linear fashion as the percentage of castor esters increased in castor esters diesel blends.
► Only slight increase in viscosity was found from B40 to B60 mixtures with No. 2 diesel.
► Castor esters only showed limited reduction in viscosity with ten selected chemical additives.