Optimización de la co-digestión anaeróbica de subproductos pasteurizados de mataderos que incorporan residuos de la industria del bioetanol para equilibrar las relaciones C/N

Abstract

Anaerobic digestion of pig slaughterhouse waste (SW) and corn sieving waste (CSW), and anaerobic co-digestion of CSW/SW were studied at lab scale employing several carbon to nitrogen ratio (C/N) and total solids (TS) content. Mixtures with highest biogas yield and suitable process stability values were scaled up to pilot scale. Results showed that SW and CSW co-digestion improved biogas yield over that obtained from mono-digestion of both substrates. Thus, CSW could be a proper substrate to balance C/N and improve biogas yield. Also, all studies reveal that the best biogas yield for each C/N mixture was achieved for the lowest TS content. Moreover, SW/CSW mixture with C/N 15 and 5% TS achieved the highest biogas yield and the best process stability. Pilot scale assay demonstrates that biogas yield, methane yield and Organic Matter Removal (OMR) for C/N 15 mixture were 41%, 25%, and 24% higher than those using C/N 20, respectively. Methane content was similar for both C/N 15 and C/N 20 at pilot scale. However, other gasses composition (H 2 , CO 2 ) presented variations.