Feedstock-temperature interactions in anaerobic digestion with focus on psychrophilic regime

Abstract

While feedstock composition and temperature are known to affect anaerobic digestion (AD) performance, their combined effect remains unexplored. By characterizing the response of AD kinetics to temperature across mesophilic and psychrophilic regimes for different agricultural residues -ranging from lignocellulose-rich crop stover to readily biodegradable potato waste–, this study aimed to study their interactive effects on AD kinetic parameters and biodegradability. Lignocellulosic material exhibited increasing biomethane potential (Bmax) with increasing temperature, while easily degradable substrates reached higher Bmax values at lower temperatures. AD rate sensitivity to temperature was lower for lignocellulose-rich feedstocks. Under mesophilic conditions, these feedstocks achieved the highest biodegradability (BD), while BD of easily degradable substrates increased with decreasing temperatures. Our findings revealed significant temperature-feedstock composition interaction effects on AD performance that holds significance for both laboratory and field-scale applications and could be used to improve the performance of psychrophilic AD in temperate-to-cold regions of developing countries.