Simulation of Spearmint Essential Oil Standardization with Fractional Distillation for Food and Pharmaceutical Industries

Despite of Iran's position as one of the leading countries in the production of spearmint (Mentha spicata L.), the extraction of spearmint essential oil (SEO) and its use in food and pharmaceutical industries are faced with challenges such as non-uniformity of product and low amount of two valuable compounds of carvone and limonene. Therefore, this study was conducted with the aim of obtaining SEO with more than 75% carvone, as well as designing and simulating the extraction process with high economic efficiency. After determining the components ofthe raw SEO and modelling the standardized SEO, the characteristics of the batch fractional distillation tower and the equipment required for the operation were modelled, and dynamic operations were simulated. The operational design of the process was performed based on the processed simulator (Aspen PLUS V.10), and its performance was analyzed. During the simulation, from 40 Kg of input feed with about 50% carvone, 18.2 Kg of standardized SEO with more than 75% carvone can be obtained. According to the results, the optimum condenser temperature and return flow to achieve maximum purity in the shortest time for the low weight compounds were 25-30°C and 3.1 ratios. The increasing temperature of the column tower caused increasing the amount of carvone in the pot and the amount of limonene in the receiver. However, the excessive temperature had an adverse effect on the output product; it reduced the amount of limonene in the receiver and increased undesirable components. Finally, the results obtained in this research can be a guide for researchers and industries to produce SEO with the desired characteristics and be helpful in designing pilot and industrial systems for essential oil extraction and standardization of other medicinal and aromatic plants.