Stabilizing anaerobic digestion under stress conditions: CO2 enrichment for enhanced methane yield and process resilience

This study explores how CO2 enrichment influences anaerobic digestion (AD) of sugar beet molasses pellets at different organic loading rates. The CO2-enriched reactor produced 10.5% more methane, showed greater stability, and recovered better from acidification than the control. Isotopic and microbial analyses revealed predominantly acetoclastic methanogenesis with minor hydrogenotrophic and methylotrophic contributions, highlighting CO2 enrichment as a promising way to enhance yield and resilience in high-load AD systems.