Performance of a Solar Distillery of Essential Oils with Compound Parabolic Solar Collectors

Abstract

The performances of a new solar distillery of essential oils with CPCs were determined for different ambient and working conditions. The essential oil distillation system was composed of seven compound parabolic solar collectors and a distillation unit. The heat transfer oil heated by CPCs was pumped to the distillation unit by a circulation pump. Eleven essential oil distillation trials were carried out in July, August and September. In some trials, compound parabolic reflectors were covered by a black fabric sheet to observe the effectiveness of solar concentration. CPC reflectors increased the total solar radiation coming onto the surface of absorber by 3.55 times on the average. When solar radiation was concentrated and the sky was without clouds, 78-80% of the total energy need of essential oil distillation was supplied from solar energy. The total solar radiation coming on the collector ranged from 23.20 kWh to 26.90 kWh in the trials. However, the occurrence of clouding during daytime required partly electrical heating to complete the distillation process. When the solar radiation was not concentrated, the distillation water could not boil without an electrical heater. 26 to 40 ml essential oils were extracted from 5 kg mint plants per day.