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Anaerobic digestion of ammonia-pretreated corn stover
- Yuan, Hairong, Li, Rongping, Zhang, Yatian, Li, Xiujin, Liu, Chunmei, Meng, Ying, Lin, Meina, Yang, Ziyi
- Biosystems engineering 2015 v.129 pp. 142-148
- acidification, ammonia, anaerobic digestion, biogas, cellulose, corn stover, digestion, hemicellulose, lignin, lignocellulose, water content
- The effect of ammonia pretreatment on the anaerobic digestibility of corn stover was investigated. Corn stover with different moisture contents (30%, 50%, 70%, and 90%) was pretreated with three concentrations of ammonia (2%, 4%, and 6%) at 35 ± 2 °C for the following batch digestion. Results showed that the reagent of 4% ammonia and 70% moisture content could achieve the highest anaerobic digestibility. In comparison with the untreated, the time needed to produce 90% of the maximum digester gas production (T90) shortened from 52 d to 37 d. The total biogas production and the unit volatile solids (VS) biogas yield were 20,740 ml and 427.1 ml respectively, both 26.70% higher than the untreated. It was found that the digesters with high moisture contents of 70% and 90% were more stable and had shorter acidification periods relative to the low moisture contents of 30% and 50%. The decreases in cellulose, hemicelluloses and lignin indicated that ammonia pretreatment could destroy the lignocellulose (LCH) structure and furthermore enhance the biogas production. Following anaerobic digestion, 80.6% of cellulose and 68.52% of hemicelluloses were consumed where there was 4% ammonia and 70% moisture content, indicating why these conditions produced the highest level of biogas.