Integration of mesophilic biogas plant in the animal slaughter process under real limitations: Techno-economic evaluation of a colombian bovine slaughterhouse
ELSEVIER, Waste Management, vol. 160, pag. 112-122, April 2023
Authors: Zamir Sáncheza ; Jaime Martí-Herrerob c ; Humberto Escalantea ; Liliana Castroa
a DGrupo de Investigación en Tecnologías de Valorización de Residuos y Fuentes Agrícolas e Industriales para la Sustentabilidad Energética (INTERFASE), Escuela de Ingeniería Química, Universidad Industrial de Santander—UIS, Carrera 27, Calle 9 Ciudad Universitaria, Bucaramanga 680002, Colombia
b Biomass to Resources Group, Universidad Regional Amazonica Ikiam, Via Tena-Muyuna, Km.7, Tena, Napo, Ecuador
c Building Energy and Environment Group, Centre Internacional de Métodes Numérics en Enginyeria, Terrassa, Barcelona, Spain
Anaerobic digestion (AD) has been a widely tested alternative for the management and valorization of wastewater from the animal slaughter process. However, the integration of AD in slaughterhouses depends on technical and economic aspects. In Colombian slaughterhouses AD integration is limited by the availability of land. In the present study, a techno-economic evaluation of the AD of offal wastewater (OWW) stream in a laboratory scale mesophilic tubular digester was carried out. The digester was operated at organic loading rates (OLR) of 0.28, 0.50, 1.0, 1.5 and 2.0 kg VS/m3 d. Boilers and a CHP (combined heat and power) system were considered for energy integration of biogas. For the economic study, the cost structure of a Colombian slaughterhouse was considered. The AD of OWW at 2.0 kg VS/m3 d OLR was unstable with risk of inhibition. Increasing the OLR from 0.28 to 1.5 kg VS/m3 d caused a reduction in the specific biogas production (SBP) from 0.474 to 0.069 m3/kg VS However, the biogas production rate (BPR) remained constant at around 0.105 m3/m3dig d for OLRs > 0.28 kg VSm3 d. Therefore, OWW anaerobic digestion in low-cost mesophilic biogas plants is technically feasible with OLRs between 0.28 and 1.5 kg VS/m3 d. The implementation of boilers is economically favorable for OLR ≥ 1.0 kg VS/m3 d. Nevertheless, feasibility is very sensitive to variations in the cost structure. The implementation of CHP was feasible in the range of OLRs evaluated and its viability is not affected by changes in assumed costs.