Comparison of thermophilic microaerobic and alkali pretreatment of sugarcane bagasse for anaerobic digestion

Abstract

In this study, the effects of thermophilic microaerobic pretreatment (TMP) and alkali pretreatment (AP) on anaerobic digestion (AD) of sugarcane bagasse were investigated. Results showed TMP was efficient at crystallinity disruption and AP was efficient at lignin removal. The maximum methane yield was obtained when the oxygen loads during TMP was 10 ml g⁻¹ VS_substrate (TMP2), which was 15.7% and 29.3% higher than those of AP and the sample without pretreatment (WP), respectively. Accordingly, the VS removal efficiency of TMP2 was 5.4% and 17.4% higher than those of AP and WP, respectively. In addition, lag-phase time of TMP2 was 1.55 and 3.82 days shorter than those of AP and WP, respectively. Technical digestion time (T90) of AP was 49 days, which was 10 and 7 days less than those of TMP2 and WP, respectively. In addition to AP, TMP is an alternative and efficient pretreatment method in the AD of sugarcane bagasse.