In a pioneering report published in Cleaner Waste Systems, Dionisio Humberto Malagón-Romero and his team presented the first integrated dual-valorization model for the native Colombian avocado variety Persea americana cv. Papelillo, a variety traditionally cultivated alongside coffee but often commercially challenged due to its rapid ripening and oxidation. This research tackled the significant waste generated by the avocado industry by integrating two complementary techniques: slow pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More for the seeds and hydrodynamic cavitation for the second-grade pulp. The overall schematic for the proposed integrated technique involves converting the pulp to edible oil via hydrodynamic cavitation and the ground seed into biochar, bio-oil, and biogas via pyrolysis .

The valorization of the avocado seeds focused on slow pyrolysis, a thermochemical process that converts biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More into high-value solid, liquid, and gaseous products. Ultimate analysis of the seeds showed a high carbon content of 43.79% and an oxygen content of 46.63%. The high carbon content is essential for biochar production, while the low sulfur content (only 0.05%) minimizes the risk of sulfur dioxide emissions and potential environmental issues like acid rain. The thermal decomposition kinetics were analyzed to gain crucial insights into the energy potential of the biomass, with activation energies estimated to range between 19.28 and 227.25 kJ/mol for different degrees of conversion. This kinetic analysis revealed that the highest energy requirement occurs at a conversion value of 0.45, corresponding to the overlapping decomposition of cellulose and lignin.

The slow pyrolysis process yielded 31.2% biochar, 3.7% bio-oil, and 59.8% biogas. The highest biochar yield of 31.2% was achieved at a temperature of 300∘C and a heating rate of 15∘C/min. This biochar product exhibited a high calorific value of 21.39 kJ/kg, indicating its potential as a solid renewable fuel. Morphological characterization via scanning electron microscopy (SEM) showed that the biochar had a rough and predominantly compact surface before adsorption. Following exposure to heavy metals, the surface became more irregular with an increased appearance of globular structures and cavities, suggesting the effective occupation of active sites by the adsorbed species.

Energy dispersive X-ray spectroscopy (EDS) confirmed the biochar’s carbonaceous nature, showing 85.26% carbon and 10.80% oxygen by mass prior to adsorption, with the oxygen indicating the presence of oxygenated functional groups that are crucial for metal binding. The most compelling finding for the biochar was its superior adsorption potential: after treatment with a heavy metal solution, EDS analysis showed that the material successfully captured lead (Pb), reaching a mass fraction of 52.2% by weight. This impressive performance is attributed to the oxygen-rich functional groups on the biochar surface, which promote cation exchange and surface complexation with heavy metals.

The bio-oil yield of 3.7% contained a diverse mixture of oxygenated compounds, including alcohols, acids, esters, alkanes, alkenes, hydrocarbons, and aromatic compounds, confirming its potential as a bio-based feedstockFeedstock refers to the raw organic material used to produce biochar. This can include a wide range of materials, such as wood chips, agricultural residues, and animal manure. More for green solvents or additives. The biogas fraction, at approximately 60% yield, was dominated by carbon dioxide (20,287 ppm) with a minor methane contribution (201 ppm). This composition suggests a low intrinsic energy potential, reflecting the biomass’s high intrinsic oxygen content and the slow pyrolysis conditionsThe conditions under which pyrolysis takes place, such as temperature, heating rate, and residence time, can significantly affect the properties of the biochar produced.   More, which favor the production of stable, oxygenated gaseous species like carbon dioxide. However, this biogas can be used to sustain the pyrolysis process itself, supporting the study’s circular economy model.

The second valorization route involved extracting oil from second-grade avocado pulp using hydrodynamic cavitation, a green and energy-efficient method. Under optimal conditions, the process achieved an exceptional oil extraction yield of 69.16% in just 15 minutes, outperforming other conventional methods like hot water separation (21.4%−23.2%) and hexane solvent extraction (54%). Furthermore, the method demonstrated remarkable energy efficiency, requiring a low specific energy intensity of only 990 kJ/kg. The resulting edible oil exhibited advantageous physicochemical characteristics, including a density of 0.9102 g/mL and a viscosity of 68.4 mPa⋅s. It also presented a favorable fatty acid profile rich in polyunsaturated fatty acids, such as linoleic acid (21.78%), confirming its high nutritional and nutraceutical potential.

In conclusion, this dual valorization strategy successfully transforms the byproducts of the native Papelillo avocado into multiple valuable products—a highly adsorptive biochar, a bio-oil feedstock, and a high-quality edible oil—thereby offering a replicable, sustainable, and economically viable framework for regional bioeconomic development in Colombia.

Source: Malagón-Romero, D. H., Velasco-Peña, M. A., Arrubla-Vélez, J. P., Clavijo-Barreto, L. F., Barrera-Mendoza, I. N., & Jiménez-Montero, E. D. (2025). Valorization of Colombian Native Avocado (Persea americana cv. papelillo): biochar, bio-oil, biogas, and edible oil production. Cleaner Waste Systems, 100458.