Pore size and adsorptive capacity of unburned carbon affected by gasification with carbon dioxide

Gasification of unburned carbon by using CO2 gas at temperatures of 950-1100 degrees C was performed, in order to modify the pore size distribution and adsorptive capacity of the carbon. Equipments such as N2 adsorption apparatus, mercury pore size analyzer, and SEM were used, where yield, specific surface area and methylene blue number for adsorptive capacity, pore size, and appearance of the carbon were analyzed. Results show that gasification of unburned carbon produces larger adsorptive capability as well as a larger specific surface area. While reacting with CO2 at 1100 degrees C for 45 min, the methylene blue numbers reach to 54-154 mg/g, and the specific surface areas reach to 113-235 m2/g, which signify the actual utility. All carbons in gasification form new pores in a mutual size approximately 0.1-0.01 microm, whose majority affects the adsorptive capacity and specific surface area of the carbon. Besides, their group appearance complies with the obvious flow-like pattern, containing carbon ingredients with various degrees of crystallinity in the surface of unburned carbon. The new pore, conclusively, forms from the lower crystalline carbon ingredient that gasified with CO2 earlier, in the flow-like pattern.