Synthesis of Mesoporous Carbon Adsorbents Using Biowaste Crude Glycerol as a Carbon Source via a Hard Template Method for Efficient CO2 Capture

Biowaste utilizationas a carbon source and its transformationinto porous carbons have been of great interest to promote environmentalremediation owing to biowaste's cost-effectiveness and usefulphysicochemical properties. In this work, crude glycerol (CG) residuefrom waste cooking oil transesterification was employed to fabricatemesoporous crude glycerol-based porous carbons (mCGPCs) using mesoporous silica (KIT-6) as a template. The obtained mCGPCs were characterized and compared to commercial activatedcarbon (AC) and CMK-8, a carbon material prepared using sucrose. Thestudy aimed to evaluate the potential of mCGPC asa CO2 adsorbent and demonstrated its superior adsorptioncapacity compared to AC and comparable to CMK-8. The X-ray diffraction(XRD) and Raman results clearly depicted the structure of carbon naturewith (002) and (100) planes and defect (D) and graphitic (G) bands,respectively. The specific surface area, pore volume, and pore diametervalues confirmed the mesoporosity of mCGPC materials.The transmission electron microscopy (TEM) images also clearly revealedthe porous nature with the ordered mesopore structure. The mCGPCs, CMK-8, and AC materials were used as CO2 adsorbents under optimized conditions. The mCGPCadsorption capacity (1.045 mmol/g) is superior to that of AC (0.689mmol/g) and still comparable to that of CMK-8 (1.8 mmol/g). The thermodynamicanalyses of the adsorption phenomena are also carried out. This workdemonstrates the successful synthesis of a mesoporous carbon materialusing a biowaste (CG) and its application as a CO2 adsorbent.