Megido L(1), Negral L(2), Fernández-Nava Y(2), Suárez-Peña B(3), Ormaechea P(2), Díaz-Caneja P(4), Castrillón L(2), Marañón E(2). Author information:
(1)Department of Chemical and Environmental Engineering, University of Oviedo,
Gijón, Asturias 33203, Spain. Electronic address: [Email]
(2)Department of Chemical and Environmental Engineering, University of Oviedo,
Gijón, Asturias 33203, Spain.
(3)Department of Materials Science and Metallurgical Engineering, University of
Oviedo, Gijón 33203, Asturias, Spain.
(4)ALIMERKA Corporation, Llanera 33690, Asturias, Spain.
A mixture of supermarket food waste from bakery, butchery, cooked meats and cheese, fishmonger, fruit, and vegetable sections was subjected to anaerobic digestion under thermophilic conditions (55 °C). Lab-scale induced bed reactors (IBR) and completely stirred tank reactors (CSTR) were operated at different organic loading rates (OLR), i.e., 3.0, 3.6 and 4.6 kg volatile solids (VS) per m3 of reactor and day. Regardless of the type of reactor, an OLR of 3.6 kg VS/m3·day was found to be the optimum, achieving up to 48.1% more methane production per kg of treated waste than for the other OLRs tested. In general, there were no statistically significant differences (p-value < 0.05) between IBR and CSTR performance at the same OLR tested. However, for the optimum OLR, the IBR achieved a mean methane production of 1.5 L CH4/Lreactor·day (426.7 L CH4/kg VS) and the highest VS removal (89.0%, on average). This reactor obtained 22.1% more CH4 yield than the analogous CSTR and the highest methane content in the biogas (66.9% CH4). Finally, the process was successfully tested under large-scale conditions (1.25 m3 IBR pilot-plant). The CH4 production and the biodegradation yield were in line with those obtained in the lab-scale IBR.
Having over 250 Research scholars worldwide and more than 400 articles online with open access.