Improved performance of corn stover anaerobic digestion by low-temperature hydrothermal pretreatment with urea enhancement
2022
Lu, Yao | Yuan, Hairong | Yan, Beibei | Zuo, Xiaoyu | Li, Xiujin
This study investigated the improved performance of corn stover anaerobic digestion (AD) by low-temperature hydrothermal pretreatment (HP) enhanced with urea. HP enhanced with urea achieved the maximum biomethane yield of 241.9 mL g VS⁻¹ and reduced digestion time (T₈₀), which were 19.6% higher and 6 days shorter than for the control, and volatile solid (VS) conversion was improved up to 16.8%, correspondingly. The results indicated that HP could hydrolyze hemicellulose and that urea could enhance the depolymerization of lignin to phenols and supplementary nitrogen. The variation in the diversity and composition of the bacteria and archaea in AD were observed between pretreated and untreated corn stover. The abundance of DMER64, Sedimentibacter, Mesotoga, and Methanosarcina was enriched by HP with urea. The main pathways and metabolism module analyses showed that urea improved methanogenic activity, which was attributed to better balance of nutrition in the AD system. This study demonstrated that the combination of low-temperature HP with urea could improve the biomethane yield and increase AD efficiency.
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