Adsorption of CO2 on agricultural waste biochar: synthesis, experimental and kinetic studies
摘要
Climate change is a pressing issue that requires immediate attention and action. A significant factor contributing to greenhouse gas emissions is CO2. To mitigate the impacts of climate change, it is essential to explore strategies aimed at decreasing atmospheric CO2 levels. The Rice Husk Biochar (RHB) synthesized in a pyrolysis furnace and its CO2 sorption was investigated in a thermogravimetric analyzer. The CO2 uptake capacities at atmospheric pressure on the non-commercial Rice Husk Biochar with a 38.12 m2/g specific surface area at 280, 300, and 320 K are 3.0, 2.0 and 1.25 mmol/g solid, respectively. Kinetic studies have also shown that the adsorption of CO2 on biochar follows a diffusion, nucleation and growth, and geometrical contracting volume mechanism, indicating that the process is highly efficient and rapid; facilitating the rapid removal of CO2 from the atmosphere. Knowing the adsorption kinetic is essential for the design of the scaling-up adsorption systems. Low mean activation energy (5.42 kJ mol−1) estimated with a free model confirm a rapid reaction rate. The use of agricultural waste biochar for CO2 adsorption offers a sustainable and effective alternative material to address the challenge of carbon dioxide emissions with further innovation in activation, surface area and texture improvements.