Exergetic Evaluation of Dual Production of Oil and Biochar from Native Avocado in Northern Colombia

The Colombian Caribbean is a strategic area for avocado production, not only because of its favorable climatic conditions, but also because of the availability of varieties with a high content of compounds of industrial interest. The Creole-Antillean avocado grown in Montes de María represents a significant source of raw material with potential for processing, both because of the lipid fraction of its pulp and the chemical composition of its seed. However, the use of this resource has been limited by low technology incorporation and poor coordination of agro-industrial chains that would allow its valorization beyond fresh consumption. In view of this situation, the design of a plant for the simultaneous production of oil and biochar is proposed, with the aim of migrating from a linear model to a comprehensive biomass valorization scheme. The study analyzes the performance of the process from a thermodynamic perspective, applying an exergy analysis that allows for the evaluation of the quality of the energy used and the quantification of irreversibilities at each stage. The results indicate that the highest exergy destruction occurs during seed washing (12.37%), oil extraction and centrifugation (19.71%), distillation and condensation (20.64%), and pyrolysis with by-product separation (28.72%). Although the seed washing stage showed high exergy efficiency (99.81%) when integrated into biochar production, stage 12 recorded a significant loss of 2438.52 MJ/h, associated with the non-use of the volatile gases generated in pyrolysis. Overall, the exergy efficiency of the system reached 30.07%, reflecting the high thermodynamic demands involved in transforming the seed into a high-value product such as biochar. This type of assessment not only identifies critical points of exergy destruction, but also establishes technical bases for optimizing energy consumption, reducing losses, and moving towards a more efficient and sustainable process.