Abstract

ZELAYA-BENAVIDEZ, EA; MARTINEZ-GUTIERREZ, GA  and  ROBLES C, MORALES, I. Use of mezcal vinasses to produce methane by co-digestion with bovine manure. Biotecnia [online]. 2022, vol.24, n.2, pp.53-58.  Epub May 19, 2023. ISSN 1665-1456.  https://doi.org/10.18633/biotecnia.v24i2.1501.

The best co-digestion ratio between mezcal vinasses and bovine manure was investigated to produce methane. Five vinasses and bovine manure mixtures in different proportions were compared (v/v): 25-75, 50-50, 75-25, 100-0, and 0-100, with six replications. As reactors, 496 mL glass containers with hermetic seal were used, with 300 mL of active volume under mesophilic conditions (36 ± 1 oC) for 10 days. The pH, total solids, and volatile solids of vinasses, bovine manure, and their mixtures were determined in triplicate. The methane accumulated volume was greater with the 0-100 and 75-25, followed by the 100-0, with 286.23, 286.40, and 225.48 NmL CH4, respectively. Methane yield was higher with 100-0 and 75-25 with 28.27 and 22.77 NmL CH4 g-1 volatile solids, respectively. The Gompertz bacterial growth model showed that the micro-organisms adaptation period in vinasses was longer than in bovine manure. Co- digestion of vinasses and bovine manure in proportion 75-25 % improved the methane production by 26.7 % with respect to the digestion of vinasses alone, and reduced the adaptation time of bacteria to vinasses by 4.12 days.

Keywords : agave; agro-industrial waste; biogas; biomethane.