Analysis of viable biogas production from anaerobic digestion of swine manure with the magnetite powder addition

Abstract

The development of new technologies during the processes of Anaerobic Digestion (AD) has occurred through the use of new types of additives, to maximize the CH 4 production. Therefore, this study aimed to technically analyze the effect of magnetite powder in the AD process of the pigs’ litter in anaerobic reactors under mesophilic conditions. In this sense, the experiments were carried out in triplicate under two sequential processes to analyze the physicochemical characteristics and concentrations of trace elements (Fe, Zn, Mn, and Cu) before and after AD. The volume of biogas and yields of CH 4 were analyzed under normal conditions of temperature and pressure, to infer the role of magnetite in the digestion process. The results showed that the magnetite powder has a significant impact on yields of methane during the digestion process of pig slurry. The maximum methane generated were 3.82.10 −2 Nm 3 CH 4 /kg V S with the addition of 8 g of magnetite. The minimum methane produced was 2.18.10 −1 Nm 3 CH 4 /kg V S with the addition of 12 g of magnetite. The concentrations of trace elements were consistent with the literature data contributing to the smooth progress of the enzymatic activities of the methanogenic microorganisms. • The effect of magnetite in the anaerobic digestion process of the pigs’ litter in Brazilian meat sector was analyzed. • A sequential batch reactor in a small-scale promoted the highest organic reduction of 86.36%. • The maximum methane generated were 3.82 x 10 -2 Nm 3 CH 4 /kg VS. • The results displayed are based on the subtropical climate of dry winter (Cwa).