Solid residues after gasification of agricultural residues as scalable and economical CO2 adsorption materials

Economical CO₂ adsorbents are gaining significant attention as viable solutions to combat climate change. This research assessed the CO₂ adsorption potential of solid residues following the gasification of bagasse (SR-Bagasse), bamboo (SR-Bamboo), and rice husk (SR-Rice husk) in various systems in Vietnam and Cambodia. Among these residues, SR-Bagasse showed the highest CO₂ adsorption capacity, followed by SR-Bamboo, while SR-Rice husk exhibited moderate performance. The CO₂ adsorption capacity at 25 °C with 100 % CO₂ flow varied from 6 % to 9.5 % of the adsorbent's weight. Under flue gas conditions (15 % CO₂ and 85 % N₂), the adsorption capacity ranged from 2 % to 5 %. Additionally, these chars demonstrated significant recyclability with 90 % of initial adsorption capacity retained after 30 cycles, making them comparable to several advanced CO₂ adsorbents studied previously. The highest performance of SR-Bagasse could be attributed to its substantial microporous and ultra-microporous volumes, with micropores serving as both CO₂ adsorption sites and conduits to ultra-micropores. This study's findings emphasize the potential for integrating energy production with the development of economical and scalable CO₂ adsorbents for industrial use.