Numerical optimization of guaco leaves extraction based on pre‐heat treatment

Abstract

AbstractThe mass yield of the extraction is influenced directly by the pre‐treatment conditions of the raw material. In the case of leaves, drying is required to ensure their biological stability and is a pre‐processing step that demands large amounts of thermal energy. In the present study, the oil extraction process was numerically optimized, considering the influence of the pre‐heat treatment of the guaco leaves. An operating range between 30°C and 70°C, 1.0 and 5.0 m/s, and recirculation between 0 and 1 was evaluated. The minimum ratio of energy consumption of drying by the amount of oil obtained after extraction (4.05 × 105 kWh/kg) was obtained under the optimal conditions of 30.02°C, 1.0 m/s, and .129 of air recycling flow rate. With our results, it is possible to guarantee safety in the storage of guaco leaves, in addition to optimizing the extraction process, maximizing the obtaining of the oil mass, and reducing energy consumption in the drying step.Practical applicationsTea is one of the most consumed beverages in the world and is obtained by extraction. Between tea leaves, guaco (Mikania glomerata Sprengel) is mainly applied to obtain therapeutic properties as an expectorant and bronchodilator. While guaco leaves are perishable, they must be dried to ensure their biological stability. As others heat and mass transfer processes, the efficient design is mandatory to reduce energy consumption. One of the more efficient drying processes is the operation under exhaust air recirculation. Thus, there is a need to evaluate optimal drying operation conditions to understand the effects of exhaust air recirculation on the energy consumption of drying and the amount of extract obtained in the extraction. Our numerical results indicated that it is possible to guarantee safety in storing guaco leaves and optimize its extraction process.