2010 Volume 35 Issue 2 Pages 267-270
Carbon materials were formed from coffee wastes by gas activation process using microwave heating for rapid production, and this material showed cell geometry and micro pores at cell surface. The relationship between the pore characteristics of these materials and the activation conditions were studied. A 2.45 GHz microwave controlled at 100 W irradiated the coffee wastes for carbonization during 105 min, and the gas activation process performed by microwave power varied from 100 to 500 W with Ar and gas mixture of Ar and CO2. N2 adsorption isotherm profiles at 77 K indicated the Langmuir type profile. The specific surface area and the micro-pore volume reached to 357 m2/g and 16.5×10-2 cm3/g at 490 W microwave power with the gas mixtures, respectively. Structure of carbon material clearly reveals cell geometry. The averages of the cell partition wall thickness decreased as the specific surface area and the micro-pore volume increased. These results suggest that the cell geometry and pore characteristics of carbon materials can be controlled by microwave power.
