Co-ensiling of rice straw and distillers grains to increase methane production and maximise energy output

• DOI: 10.1016/j.biortech.2023.129496
• Publication Date: 2023-07-18T00:40:19Z
• Authors: Xuan Luo; Yuhuan Liu; Luyao Lei; Jiali Shen; Qi Zhang; Yunpu Wang; Roger Ruan; Xian Cui
• Keywords: Distillers grains; Rice straw

High organic matter preservation during ensiling promotes material conversion and energy output. In this study, the effects of co-ensiling distillers grains and rice straw on methane production was evaluated, as distillers grains are highly acidic. For co-ensiling, distillers grains and rice straw were mixed to produce methane at five carbon/nitrogen (C/N) ratios. RD20 (C/N20) and RD25 (C/N25) were defined as high-distillers-grain groups and other mixed groups as low-distillers-grain groups. The results showed that Lactobacillus was enriched in RD25, with the highest lactic acid content reaching 54.0 g/kg of dry matter. The pH and organic dry matter loss of RD25 were lower than those of low-distillers-grain groups, but the result for lignocellulose degradation rate was reversed. An 8.6% increase in methane yield and 7.9% increase in energy output were achieved in RD25. Ensiling-anaerobic digestion systems of C/N25 provide high organic matter preservation and energy output.