Microwave-assisted enhanced activation of date palm leaf char for optimized CO2 adsorption

Abstract

Abstract This study presents a novel hybrid approach for producing mesoporous activated carbon (AC) from date palm leaves by integrating conventional carbonization with microwave-assisted activation. K₂CO₃ was utilized for chemical activation to enhance adsorption performance. Three critical parameters, namely microwave power, residence time, and activation temperature, were investigated focusing on yield, temperature ramp-up time, and CO₂ capture capacity. Results reveal that both microwave power and activation temperature were pivotal in influencing the yield and adsorption efficiency. Microwave-assisted activation (850 W, 500 °C, 7 min) yielded an optimal CO₂ adsorption capacity of 126.7 mg/g at 25 °C and 1 bar, with 78% and 76% reductions in activation energy and processing time, respectively. This method enhanced the textural properties of the activated carbon, increasing the surface area to 411 m²/g and improving pore size distribution, as compared to conventional thermal activation (60 min under CO₂), which achieved only 88 mg/g uptake and a surface area of 286 m²/g. Compared to conventional methods, the hybrid approach reduced energy and time demands to about 25%.