Most of researches carried out for sunflower derived biodiesel
observed values of kinematic viscosity of 4.0e4.5 mm
2
/s and
density of 80050 kg/m
3
[20]. However, in the case of castor bean
the values are different; although the density of castor oil derived
biodiesel is near the above mentioned levels, i.e. 850e960 kg/m
3
[21], the kinematic viscosity at 40
C is in most cases, significantly higher; they reported kinematic viscosity 1.l8e15.5 mm
2
/
s. Castor oil consists mainly of esters of 12-hydroxy-9-octadecenoic
acid (ricinoleic acid) and is characterized by high viscosity due
mainly to hydrogen bonding of its hydroxyl groups, although this is
unusual for a natural vegetable oil[22].