Castor oil as an innovative raw material for an energy supply chain in semi-arid environments

Increasing energy demand and fossil fuel prices together with environmental concerns have motivated scientists to find alternative energy sources such as biofuels. Biofuels are renewable and biodegradable sources of energy with beneficial environmental impacts. Biodiesel is a mixture of mono alkyl esters of vegetable oils or animal fats. Currently, more than 95% of the world biodiesel is produced from edible vegetable oils through different transesterification systems. Castor oil is an excellent raw material in terms of price and quality, but especially this non-edible vegetable oil does not have any issues or compromise food security. Recently, the use of castor oil has attracted attention for producing and optimizing biodiesel production, due to its high content and the possibility to esterify with only methanol, which assures low production costs. Additionally, the use of feedstocks as vegetable oils can contribute to decreasing greenhouses gases such as carbon dioxide, because these oils are obtained from crops which have previously captured this gas during their photosynthetic process. The innovative aspect of this study is the evaluation of the morphologic and productive response of castor bean to changing soil water and nitrogen fertilization under the semiarid Mediterranean climate.