Production of Sustainable Adsorbents for CO₂ Capture Applications from Food Biowastes

Abstract

Traditional methods to develop biomass-based carbon adsorbents generally involve carbonization followed by chemical or physical activation. However, routes involving the hydrothermal treatment of biomass are receiving growing interest. In this work, two different strategies for the synthesis of sustainable CO2 adsorbents are compared, i.e., in situ ionic activation and hydrothermal treatment followed by activation with CO2. The latter is a green and simple procedure that does not require the addition of chemicals or acid-washing stages, and which leads to carbon adsorbents with relatively high CO2 adsorption capacity at low pressures, up to 0.64 mmol g−1 at 15 kPa and 50 °C, conditions relevant for postcombustion CO2 capture applications. On the other hand, in situ ionic activation can lead to carbon adsorbents with superior CO2 adsorption capacity in the aforementioned conditions, 0.78 mmol g−1, and with reduced cost and environmental impact compared to conventional chemical activation.

Keywords

• CO₂ capture
• adsorption
• hydrothermal carbonization
• biomass
• in situ ionic activation
• activated carbon