Effect of thermal hydrolysis on anaerobic digester performance

Abstract

Anaerobic digestion (AD) has been recently introduced as a promising technology for producing bioenergy around the world. Due to its especial characteristics, solid waste could be considered as a proper feedstock in the digester. Retention time (RT) and rate of biogas production are two major parameters affecting the efficiency of the process. The AD procedure of biogas production consists of hydrolysis, acidogenesis, acetogenesis, and methanogenesis such that feeding materials would be processed inside the digester. The experiments have been carried out using two bioreactors with volume of 5 liters in mesopihilic contitions at 35 ± 1°C. The purpose of this study is to accelerate the hydrolysis step. Pretreatment of the waste is accomplished using thermal hydrolysis in conditions of 155°C and 5 atm. The results of this research indicated 33.33% decrease in RT and 154.87% increase in amount of biogas production using pretreatment process in comparison without considering it.