Kinetics assessment and modeling of biogas production by anaerobic digestion of food wastes and acclimated sewage sludge

• Published in: Journal of material cycles and waste management 2021-07, Vol.23 (4), p.1646-1656
• Main Authors: de Oliveira, Laís Roberta Galdino, dos Santos Filho, Derovil Antonio, Fraga, Tiago José Marques, Jucá, José Fernando Thomé, da Motta Sobrinho, Maurício Alves
• Format: Article
• Language: English
• Subjects: Anaerobic digestion; Biogas; Civil Engineering; Cooking; Emissions control; Energy recovery; Engineering; Environmental Management; Food; Food waste; Greenhouse gases; Household wastes; Inoculum; Kinetics; Materials recovery; Methane; Original Article; Raw materials; Reactors; Refuse as fuel; Sewage sludge; Waste Management/Waste Technology; Wastes
• ISSN: 1438-4957; 1611-8227
• DOI: 10.1007/s10163-021-01248-x

In this work, food wastes (FWs) and domestic sewage sludge (DSS) were used as raw materials for energy recovery by anaerobic digestion (AD). AD was carried out with the objective to reduce the emission of greenhouse gases and the production of biogas with high methane yield. FWs were fed in an AD horizontal reactor for co-digesting the organic fraction of waste from a university restaurant with acclimated DSS as inoculum. For this purpose, the pilot-scale reactor was operated with a residual biomass of 12.0 kg (in the proportion of 1:1 of acclimated inoculum and FW), in a semi-batch regime and produced 218 NL, with a maximum methane concentration of 88.0%. Thus, a biogas production potential of 18.16 Nm 3 /ton is obtained or a specific biogas and methane production of 0.24 and 0.21 Nm 3 /kg (VS), which can be used to generate electricity or as cooking gas. Finally, between the two kinetic models, the modified Gompertz model was the most suitable model ( R 2 0.99) to adjust the measured biogas yield and ( R 2 0.98) for the methane yield that can be used to describe the kinetics of the AD in a more reasonable way.