CO₂ Capture from Porous Carbons Developed from Olive Pruning Agro-Industrial Residue

Abstract

This work studied the synthesis of activated carbons (ACs) from olive tree pruning waste since the recovery of this abundant residue for producing AC is a sustainable and environmentally friendly alternative. The physical and KOHchemical activation processes were compared and analyzed to obtain an appropriate carbon for the adsorption of CO 2 . Highly microporous carbons were obtained after KOH chemical activation that exhibit high surface area (3526 m 2 g −1 ), micropore volume (1.20 cm 3 g −1 ), and total volume (1.79 cm 3 g −1 ). The equilibrium and kinetic behavior of carbons for CO 2 adsorption were studied using Langmuir, Freundlich, and Temkin models for the isotherms and pseudo-first-order and pseudo-second-order models for the kinetics. The chemically activated carbon was found to be the most appropriate for the capture of CO 2 at low and high CO 2 pressures, showing an adsorption capacity of 5.1 mmol g −1 at 0 °C and 1 bar. The estimated isosteric heat indicates that the CO 2 adsorption process was feasible and confirms the pure physical adsorption of CO 2 . The chemically activated carbon allowed ten reuse cycles, maintaining the capture capacity. These results confirm that ACs from olive tree pruning residue have suitable capacity and stability for application as CO 2 adsorbents.

Carbon Dioxide Adsorption within Porous Porphyrin Networks

“…Escalating atmospheric carbon dioxide (CO 2 ) levels and their detrimental impacts on global climate have intensified the quest for efficient CO 2 capture technologies . Various porous materials, including Zeolite, activated carbon, and metal–organic frameworks (MOFs), have emerged as promising candidates for CO 2 capture. However, Zeolite faces challenges such as reduced CO 2 capture efficiency in moist conditions due to water saturation, limited pore volume, and the need for regeneration at high temperatures. , Similarly, activated carbon encounters issues related to pore engineering and low CO 2 selectivity, and MOFs are constrained in CO 2 capture under humid conditions; the metal sites within MOFs exhibit a stronger affinity for water bonding over CO 2 .…”