Extraction of essential oil from lemon grass through hydro distillation methods using solar and biomass energy

Abstract

The extraction of essential oils from medicinal plants, traditionally achieved by using conventional energy sources such as LPG, wood and others, which are costly and detrimental to the environment. This study focused on using solar and biomass energy to process five pre-treated shade-dried Lemongrass samples [fresh (S1), 12 h (S2), 24 h (S3), 36 h (S4) and 48 h (S5)] for essential oil extraction using hydro distillation method. A complete set of distillation unit with 16 m2 Scheffler solar collector is provided, which can generate temperature of between 300 and 450°C when exposed to beam radiation ranging from 800 to 850 W/m2. It works efficiently only on sunny days; so a backup energy source is required hence; biomass distillation system (BDS) is utilised. The thermal energy required for a 5 kg, S3 sample with 10 L of water was 10.32 and 10.62 kWh, and extracted oil was 43.8 and 46.4 ml, in solar distillation system (SDS) and BDS, respectively, which is the maximum oil yield. Statistical analysis was tested at the 1% significant level by central composite model. The system has been proven to be economically feasible, with the extracted oil having similar physicochemical properties as the available market oil.