Methylotuvimicrobium alcaliphilum 20Z based biogas valorization strategy using salting-out process for simultaneous...

Methanotroph-based biogas conversion technology is gaining significant attention for its mild operating conditions and environmental benefits. Direct utilization of biogas, without removing CO₂, can enable efficient CH₄ utilization while conserving the energy typically required for CO₂ separation, which demands substantial thermal energy. However, a key challenge lies in the substantial consumption of buffer solutions due to CO₂ dissociation at high pH (8.9-9.1), which increases the operating costs. To overcome this limitation, a novel salting-out process is proposed to recover Na⁺ ions from NaOH solutions, integrated with ectoine production using Methylotuvimicrobium alcaliphilum 20Z. The proposed system incorporates a continuous cultivation system to simultaneously recover HCO₃^- ions generated during CO₂ dissociation and Na⁺ ions introduced during the biological process. By establishing a multi-reaction system capable of converting CH₄ and CO₂ simultaneously, this study pioneers a pathway for the biogas-based production of high-value chemicals, offering significant advancements over existing technologies.