Energetic biorefinery from waste avocado seed (Persea americana cv. ‘Hass’)

Abstract

In Mexico, almost 90.2% of the energy comes from fossil fuels. The avocado Hass “Persea americana” is a product of great commercial importance; however, its processing is associated with waste generation, which usually is not managed properly. It is important that this type of by-product could be re<<<valorized to reduce the environmental footprint of this industry while value-added products are obtained. In the present work, the characterization of the residual defatted avocado seed was carried out, analyzing its moisture content, total, volatile, and fixed solids, ash content, and oil extraction was also carried out, and the fatty acid profile was analyzed. The seed presented 52.82% humidity, 95.68% total solids, and 97.78% volatile solids, which suggests good potential for biofuel transformation. Seed oil extraction with solvents showed a yield of 3.6%, with a fatty acid profile that indicates that it could be used for good-quality biodiesel production. On the other hand, the best methanogenic potential of the defatted seed showed a total accumulated production of 178.94 ± 4.90 milliliters of methane per gram of volatile solid (mL CH4/gVS). Furthermore, the digestate generated from the anaerobic digestion of the defatted seed with the Be-Gaia inoculum showed good potential as a biofertilizer, maintaining results similar to commercial fertilizer. This work's results suggest that it is possible to generate process routes for an energy biorefinery that takes advantage of the Persea americana “Hass” avocado residual seed from this material.