Pretreatment and Nanoparticles as Catalysts for Biogas Production Reactions in Pepper Waste and Pig Manure

Abstract

The circular economy is based on using waste generated from any process to obtain products with zero residues' criteria. This research was focused on pepper waste from the polyphenolic extraction method. Pepper waste was evaluated in batch and semi-continuous regime anaerobic digestion, adding, as catalysts, absorbent nanoparticles and/or using pretreatment strategies. The best methane yields were obtained from SB1 (assay without pretreatment in pepper waste): 464 ± 25 NL kg VS−1 for batch assays; and from period II (1.47 g VS L−1 d−1) of S2 (assay of pig manure and pepper waste with thermal pretreatment): 160 NL/kg VS−1 for semi-continuous experiments. However, a kinetic study showed a methane production rate higher for SB2 (assay with nanoparticles as catalyst) than SB1 in batch assays.