Kinetic Analysis of Biogas Production from Brosimum alicastrum Seed Coat Pretreatment Using a Logistic Model

Methane production from Brosimum alicastrum seed coat was evaluated using a logistic model through three alkaline concentrations (0.19 M, 0.26 M, and 0.28 M) and three enzymatic activity levels (3000 U mL^-1, 5000 U mL^-1, and 7000 U mL^-1) as pretreatments. Laccase was produced through submerged fermentation using T. hirsuta Bm-2 fungi, while NaOH served as the alkaline agent. Enzymatic pretreatment resulted in the highest specific CH₄ yield (427.43±2.28 mL CH₄/g VS_added), surpassing both alkaline pretreatment (235.61 ± 9.19 mL CH₄/g VS_added) and the control (102.54 ± 5.55 mL CH₄/g VS_added). Kinetic analysis of CH₄ production indicated that cumulative CH₄ production reached its stationary phase within 30 days of digestion. Moreover, enzymatic pretreatment exhibited the highest CH₄ formation rate (0.15–0.17 h^-1), except for the control, which had a slightly higher rate (0.21 h^-1). The kinetic analysis revealed that the enzymatic pretreatment significantly improved the hydrolysis stage of Ramon's seed coat, promoting higher cumulative CH₄ production and leading to an increased specific CH₄ yield.