(18h) Ultra-Functional CO2 Capture Sorbent Development Via One-Pot Deep Eutectic Solvent Based Thermochemical Conversion

Rising global emission of carbon dioxide (CO₂), a greenhouse gas, mostly as a result of the frightening amount of fossil fuel combustion has urged the research community towards CO₂ capture and utilization. Increased attention in deriving highly functionalized and simultaneously inexpensive CO₂ capture sorbents is therefore the primary challenge which can be circumvented via utilization of forest residues like loblolly pine (LP) and environmentally friendly solvents like deep eutectic solvents (DES). This study, therefore, investigates one-pot functionalization during the step of thermochemical conversion of LP, by using DES as the medium of reaction, where the resulting hydrochars were further chemically activated using melamine to improve the N-containing functionalities in the activated hydrochars employed for CO₂ capture. Ultra-functional LP hydrochars were derived utilizing choline chloride-urea, methyl triphenyl phosphonium bromide-ethylene glycol. The mixture of LP and DES were hydrothermally carbonized at 170, 200, and 260°C followed by chemical activation at 800°C and functionalization at 500°C using activation agents of either KOH, melamine, or a combination of KOH and Melamine. The samples’ surface area and porosity were then quantified through the utilization N₂ adsorption–desorption. X-Ray powder diffraction and thermographic analysis were respectfully employed to observe the crystallinity and thermal stability of the samples. Lastly CO₂ capture was assessed for the sorbents in atmospheric condition where results suggest exceptional multifold increase of CO₂ adsorption due to the one-pot functionalization, resulting from the enrichment of surface N-functionalities, in combination with ultra-high porosity of the adsorbents.