Utilisation of solar energy for essential oil extraction: an overview

Abstract

Essential oil extraction by distillation method requires heat in the range of medium temperature which could be supplied by various methods such as biomass, LPG and solar thermal systems. Out of these popular methods used, the solar thermal system provides the extraction system more efficient and economical. In this paper, a systematic review approach in the field of the solar thermal system used for the extraction of essential oil is adopted. The paper describes the available types of solar distillation systems as well as solar hybrid distillation system in the first part and the second part presents the theoretical analysis of the solar distillation system followed by its chemical analysis. The review findings clearly reveal that the solar distillation system is a cost-effective, innovative as well as a sustainable option for essential oil extraction. The factors affecting the solar distillation system were found as packing density, water-to-grass ratio, temperature inside the distillation still, steam flow rate and batch size. The scope of development of further research in the field of solar distillation system along with its recommendations is also the essence of this paper.