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[Display omitted] • Co-digestion of 45.7% BPS, 26.2% SCB and 28.1% CM produced 186.5 mL/g VS methane. • This co-digestion strategy provided a synergistic effect of 37.1% on methane yield. • A higher microbial diversity was found in co-digestion due to the balanced nutrition. • The predominant microorganisms in co-digestion were Choroflexi with a proportion of 39.3%. • Enriched hydrogenotrophic Methanobacterium and Methanolinea were found at high OLR. Balanced nutrition is important for maximizing anaerobic digestion (AD) performance. Herein, the strategy of balancing sugar-fiber-nitrogen nutrients was first established for improved methane production by co-digesting two agricultural and one livestock wastes with complementary compositional properties, such as banana pseudo-stem (BPS), sugarcane baggage (SCB), and chicken manure (CM) having high sugar, fiber and nitrogen contents, respectively. The maximum methane yield was 186.5 mL/g VS added with a mixture of 45.7% BPS, 26.2% SCB and 28.1% CM (with 1: 11.3: 0.3 of sugar to fiber to nitrogen ratio), increasing by 16.1%, 53.3%, 122.6% than those of mono- BPS, SCB, and CM, respectively. The co-digestion process remained stable under an organic load of 4 g VS/(L·day), which was attributed to the predominant presence of Bacteroidetes, Proteobacteria, Thauera , uncultured_bacterium_p_Aegiribacteria , and hydrogenotrophic methanogens. This study provides a deeper understanding of the co-digestion with agricultural and livestock wastes from the perspective of nutrient balance. [ABSTRACT FROM AUTHOR]

The sustainability of biogas production from straws is limited by the collection, transportation, storage, and pretreatment of feedstocks. To address these constraints, this study investigated briquetting as a pretreatment strategy for rice straw (RS) to increase bioenergy generation. The results indicated that briquetted RS yielded 205.4 mL/g VS of methane, which was 11.7% higher compared to that produced by the untreated RS. The economic analysis revealed that the briquetting process had positive effects with a payback time of 3.4 y and an internal rate of return of 23.4%. It also reduced feedstock transportation and storage costs by 42.6%. Adding a NaOH treatment to the briquetting process increased methane production by 26.4% compared to untreated RS. However, the integration of briquetting with NaOH treatment might be an unprofitable method for processing RS. This became apparent when examining the production cost, which stood at 1.13 $/kg biomethane with an internal rate of return of 16.2%, representing an 8.7% increase and a 7.2% decrease, respectively, compared to the mono briquetting method. These results revealed that briquetting as a source pretreatment strategy can improve the productivity of straw biogas plants, thereby advancing the industry towards cleaner production. [Display omitted] • Briquetting, a source pretreatment strategy, improved straw biogas production. • The briquetting strategy integrates the collection and pretreatment of rice straw. • The proposed strategy reduced straw transportation and storage costs by 42.6%. • Adding an NaOH treatment reduced the profitability of a straw biogas plant. [ABSTRACT FROM AUTHOR]