Análise Experimental e CFD-DEM do Leito de Jorro com Confinador de Fonte na Extração Mecânica de Bixina de Sementes de Urucum

Abstract

Bixin, a carotenoid derived from annatto seeds (Bixa orellana L.), is extensively used as a natural colorant in the food and cosmetic industries, as well as an antioxidant in the pharmaceutical industry. This study seeks to develop an eco-friendlier method for bixin extraction through the use of a spouted bed equipped with a draft tube and a fountain confiner, presenting a promising alternative for the economies of annatto-producing regions, such as Brazil. Experiments were performed with various draft tube diameters and confiner positions, complemented by CFD-DEM simulations to gain a deeper understanding of particle dynamics during the extraction process. The results demonstrated that smaller draft tubes combined with higher airflow rates significantly increased powder production, achieving up to 39.1 grams of powder with a bixin content of 29.1% from 2.5 kg of annatto seeds. Conversely, larger draft tubes and lower airflow rates reduced yields. Optimization using Particle Swarm Optimization (PSO) identified ideal conditions, which produced 100.8 g of powder with a bixin content of 32.53% from the same quantity of seeds. CFD-DEM simulations revealed that increasing the confiner height and the intensity of collisions improved seed abrasion, thus facilitating bixin release. Under optimal conditions, the intensified collisions contributed to finer particle fragmentation, reducing the Sauter mean diameter of the resulting powder. In less favorable conditions, collisions were insufficient, resulting in larger particles and lower bixin yield, with content below 20%. This study highlights the potential of using spouted beds with fountain confiners for natural dye extraction, offering a sustainable alternative to conventional methods.