Castor (Ricinus communis) is a fast growing ever-green tropical/subtropical shrub that produces seeds with a high oil content (35-55%).Cold pressing yields 30-36% oil measured by weight. Warm pressing (>70°C) yields 38-48%.It is usualy grown as an annual crop.
Castor oil has been used for at least 6000 years. The highly viscous oil is currently used for more than 700 products including medicine, cosmetics, lubrication, paints, and nylon. It is a hardy plant that will produce under conditions where other crops fail. It thrives well under the same conditions as Jatropha.
In the wild it is a perennial that bears seeds for up to 15 years and grows to the size of a small tree. Under cultivation it is usually grown as an annual crop. It has huge (15-45 cm) palmate (fingered) green to reddish leaves. Castor oil has long been used as lubricant in engines but only recently has research on the use of Castor oil as a biofuel started. The high viscosity presents challenges when used as PPO(pure plant oil). It can be processed into a good biodiesel, that needs to be blended with diesel for the same reason. The seeds contain extremely poisonous substances that remain in the press cake which can therefore not be used for animal feed. The oil is non-toxic….