Preparation and characterisation of carbon spheres for carbon dioxide capture

Carbon spheres were prepared by carbonisation of phenolic resin spheres obtained using a modified Stöber method in a microwave assisted solvothermal reactor. Preparation process involved water–ethanol, ammonia water, resorcinol, potassium oxalate and formaldehyde. The mixture was stirred for 24 h at room temperature and then subjected to a pressure treatment, in which the solution was treated in a microwave assisted solvothermal reactor for 15 min at a pressure of 1–3 MPa. The proposed synthesis resulted in a material containing microporous carbon spheres having high surface area (from 1178 to 1648 m 2 /g), with diameters from 200 to 350 nm, total pore volume from 0.49 to 0.78 cm 3 /g, and high CO 2 adsorption capacity from 3.86 to 5.03 mmol/g measured at 0.1 MPa and 25 °C. Taking into account the properties of the obtained material, it can be applied as a sorbent for CO 2 capture.