Characterization of agro-industrial residues for bio-oil production: chemical composition and pyrolysis potential

Abstract Agro-industrial residues represent a promising source for obtaining inputs such as bio-oil, widely used in various industrial applications. This study aimed to evaluate the potential of different biomasses—coconut fiber (COC), guava seeds (GOI), passion fruit seeds (MAR), acerola seeds (ACE), grape seeds (UVA), spent coffee grounds (CAF), corn cob (Mi,S), corn husk (Mi,P), bean pod (FEI), cassava peels (MAN), peanut shells (AMD), and pine (PNU)—as raw materials for bio-oil production based on their chemical characteristics. The biomasses were characterized through elemental analysis (CHNO), thermogravimetry (TG), and the determination of ash, moisture, oil, and total extractive contents. After the micro-pyrolysis process, the resulting bio-oils were analyzed using gas chromatography-mass spectrometry (GC–MS). The samples exhibited low ash (0.43% to 3.96%) and moisture (1.55% to 9.25%) contents, while oil and total extractive contents ranged from 0.15% to 23.26% and 4.75% to 36.37%, respectively. Thermogravimetric analysis revealed that, within the temperature range of 25 °C to 1000 °C, 82.7% to 100% of the samples degraded, indicating their viability for pyrolysis processes at 600 °C. Using GC–MS and data processing for multivariate analysis, the bio-oils were identified as complex mixtures of chemical compounds, demonstrating their potential for applications across different industrial sectors, depending on the chemical classes of interest in each biomass. Graphical Abstract Characterization of 12 types of biomasses (acerola, passion fruit, grape, and guava seeds, peanut, coconut, cassava, corn cob and husk, bean pod, pine bark and spent coffee grounds) aimed at utilizing these agro-industrial residues for the generation of value-added products.