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

Abstract

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.

Keywords

• Agricultural residues
• Adsorption
• CO2 uptake
• Gasification
• Solid residues