Insights on microalgae-based technologies with potential impact on global methane budget – Perspectives for industrial applications

The European Union’s Methane Action Plan outlined policies and targets supporting the Global Methane Pledge to cut CH₄ emissions by 30% by 2030, yet urgent implementation is needed to treat medium and diluted CH₄ streams. Microalgae-based technologies offer a groundbreaking solution, merging CH₄ mitigation with biomass valorization to drive sustainable industrial practices. This review examines three key applications: photosynthetic biogas upgrading, a viable alternative to physical/chemical methods, producing biomethane and valuable algal biomass; microalgae-methanotroph co-cultivation, a promising but underdeveloped method for diluted CH₄ streams; and CH₄-producing microalgae, unveiling a novel route for biomethane production. Despite their potential, significant research gaps remain, particularly in reactor design, culture conditions, and large-scale viability. By addressing these challenges, microalgae could revamp CH₄ management, bridging environmental goals with bioeconomic progress. This review calls for policy updates, intensified research, and industrial engagement to unlock microalgae’s full potential in CH₄ mitigation and valorization.