DEVELOPMENT OF AN INDIGENIZED SOLAR DISTILLERY FOR VALUE ADDITION OF MEDICINAL PLANTS

Abstract

of solar energy for cooking and steam generation is quite common around the world. However, the use of solar energy for the extraction of essential oils from medicinal and aromatic plants has recently been explored and the research is still in progress for its effective utilization. This study focuses on essential oils extraction using a newly designed solar distillation system. The devised system consists of a primary reflector (Scheffler concentrator), steam receiver, distillation still, condenser and a florentine flask to specifically enable extraction of essential oils from agricultural biomass and medicinal plants. An auxiliary biomass based boiler has also been coupled with the solar distillation unit to complement the devised distillation system during adverse weather conditions or seasonal climatic variations in developing countries. The pattern of steam flow and temperature distribution in the distillation still was analyzed using computational fluid dynamics (CFD) technique for design purpose. The results of CFD simulations showed uniformity in steam distribution inside the still which is necessary to get maximum oil extraction from the exposed plant material. Mathematical modeling was used to predict energy distribution at different parts of solar distillation system. Various experiments were conducted to determine the performance of the solar distillation system. The experimental results showed that essential oils produced from fresh Eucalyptus leaves (Camaldulensis), Peppermint leaves (Mentha peperita L.) and Citrus peels (Reticulata) were found to be 0.59% w/w, 0.40% w/w and 0.51% w/w on mass basis, respectively. The essential oil from Pinus (Roxburghii) was also extracted using a biomass boiler yielding 0.31% w/w of essential oil on mass basis. GC-MS analysis of the extracted essential oils confirmed the presence of Eucalyptol (50.9%), Menthol (92.99%), Limonene (85.57%) and α-Pinene (70.88%) as the major compounds in Eucalyptus (Camaldulensis), Peppermint (Mentha Peperita L.), Citrus peels (Reticulata) and Pinus (Roxburghii) essential oils respectively. The payback period of solar distillation system was found to be 0.5 years. In summary, solar-based distillation has proven to be a cost effective way of extracting essential oils from agricultural biomass, medicinal plants and herbs. Keywords: Solar distillation system, essential oils, medicinal plants, biomass boiler, CFD simulations and GC-MS analysis