Physicochemical properties, thermal behavior, and chemical kinetic analysis of Plukenetia volubilis L. (Sacha inchi) for biofuel applications

Carbonaceous materials derived from biomass are increasingly recognized as promising precursors for bioenergy applications due to their complex microarchitectures, environmental compatibility, and capacity for scalable production. Nevertheless, the direct utilization of raw biomass remains constrained by its inherent recalcitrance, which limits conversion efficiency and overall process performance. In this study, the bioenergy potential of Plukenetia volubilis L. (Sacha-inchi) shell and husk were systematically evaluated through physicochemical characterization, pyrolysis kinetic modelling, and thermal behavior analysis. The thermal decomposition kinetics were determined using isoconversional approaches at heating rates of 2.5, 5, and 10 °C·min⁻ 1 . Biochar was produced in a tubular furnace and subsequently analyzed to assess its physicochemical attributes. The higher heating values of Sacha-inchi shell and husk were 19.24 and 15.84 MJ·kg⁻ 1 , respectively. Structural analyses using XRD and FTIR confirmed the presence of cellulose, hemicellulose, and lignin, indicating suitability for biochemical extraction and renewable fuel production. Kinetic analysis using the Kissinger–Akahira–Sunose (KAS) method showed average activation energies of 219.70 kJ·mol⁻ 1 for the shell and 167.23 kJ·mol⁻ 1 for the husk, with the Flynn–Wall–Ozawa (FWO) method yielding closely comparable results. The thermodynamic parameters of the raw biomass further demonstrated its appropriateness for pyrolytic conversion. Overall, these findings highlight the potential of Sacha-inchi by-products as valuable feedstocks for bioenergy generation and related biorefinery applications. • Kinetics analysis and thermodynamic analysis confirmed multistage decomposition of Plukenetia volubilis L. • The activation energy for SIS and SIH was 219.70 kJ mol −1 and 167.23 kJ mol −1 . • The HHV for SIS and SIH was 19.24 and 15.84 MJ kg −1 . • Physicochemical, thermodynamic, and kinetic parameters highlighted the potential of SIS and SIH as a source of raw material for bioenergy.