Application of passion fruit seed meal in alternative biodiesel purification process: study of glycerol adsorption mechanism and incorporation into polymeric membrane

Abstract

Abstract The search for renewable energy sources is a global concern that strengthens the expansion of the biodiesel industry. In view of the environmental and economic problems of the conventional purification process of this biofuel, there is a need to explore alternative methods of purification. In this way, this manuscript evaluated the use of passion fruit seed meal as an alternative for biodiesel purification. In the adsorption tests, with a concentration of the biosorbent equal to 40 g L−1, at 45 °C, for 90 min, there was a removal of 72.2% of free glycerol and reduction in the content of glycerol to values below the maximum limit imposed by the legislation. Furthermore, through the characterization of the meal and the adsorption equilibrium data, it was possible to propose the mechanism involved in the adsorption process corresponds to hydrogen interactions between the glycerol and the oxygenated groups of the biosorbent. In the membrane separation process, the free glycerol removals obtained with the meal functionalized membrane were three times higher than those with the commercial membrane. Thus, the passion fruit seed meal can be a promising alternative for biodiesel purification, bringing economic and environmental advantages due to the reduction in the generation of effluents. GRAPHICAL ABSTRACT