Harnessing Ash for Sustainable CO Absorption: Current Strategies and Future Prospects.

This review explores the potential of using different types of ash, namely fly ash, biomass ash, and coal ash etc., as mediums for CO capture and sequestration. The diverse origins of these ash types - municipal waste, organic biomass, and coal combustion - impart unique physicochemical properties that influence their suitability and efficiency in CO absorption. This review first discusses the environmental and economic implications of using ash wastes, emphasizing the reduction in landfill usage and the transformation of waste into value-added products. Then the chemical/physical treatments of ash wastes and their inherent capabilities in binding or reacting with CO are introduced, along with current methodologies utilize these ashes for CO sequestration, including mineral carbonation and direct air capture techniques. The application of using ash wastes for CO capture are highlighted, followed by the discussion regarding challenges associated with ash-based CO absorption approach. Finally, the article projects into the future, proposing innovative approaches and technological advancements needed to enhance the efficacy of ash in combating the increasing CO levels. By providing a comprehensive analysis of current strategies and envisioning future prospects, this review aims to contribute to the field of sustainable CO absorption and environmental management.