Determining Optimal Temperature Combination for Effective Pretreatment and Anaerobic Digestion of Corn Stalk

Abstract

Temperature is one of the important factors affecting both chemical pretreatment and anaerobic digestion (AD) process of corn stalk (CS). In this work, the combined ways between pretreatment temperature (40℃ and 60℃) and AD temperature (35℃ and 55℃) were selected to investigate the AD performance for sodium hydroxide (NaOH) pretreated CS. Three organic loading rates (OLRs) of 1.6, 1.8 and 2.0 g·L-1·d-1 were studied within 255 days using continuously stirred tank reactors (CSTR). The results revealed that temperature of 40°C was considered as an appropriate for pretreatment whether in mesophilic or thermophilic anaerobic digestion systems. On the other hand, temperature of 35°C and 55°C were chosen as the optimal AD temperatures for lower and higher OLRs, respectively. This study provides a significant insight for exploring the effects of temperatures on the pretreatment and AD of CS.