Abstract
In Colombia, the rapid expansion of Hass avocado cultivation has increased the availability of the fruit across different regions. During avocado processing operations, residues, such as the seed or peel, account for the most significant waste fraction, resulting not only in environmental challenges associated with their elimination but also a decrease in potential economic returns. In this study, an exergy analysis was performed for a biorefinery based on hard avocado waste to produce high-value products comprising starch and biodegradable biofilms. This enabled detailed mass and energy balance calculations and the determination of thermodynamic properties for both pure compounds and mixtures. Considering this information, chemical and physical exergies were additionally obtained, and exergy parameters were quantified per stage and for the whole process. The obtained results indicate satisfactory exergy performance, with an overall exergy efficiency of 68% and a total irreversibility of 5453.58 MJ/h. Exergy analysis revealed significant sources of exergy destruction in starch production during seed drying, and starch drying-1 and 2. These stages contribute 5% and 7.20% (each), respectively, to the total exergy destruction of the process. In biofilm production, flash separation-1, fermentation, and biofilm drying exhibit the greatest exergy destruction, each contributing approximately 6% of the total process exergy destruction. The main improvement opportunities are identified in stages such as drying, flash separation, fermentation, and neutralization; thus, optimizations of these stages are suggested to maximize the overall performance of the process.
