Thesis (M.Sc.)--Chulalongkorn University, 1998

This research was the study of the production of activated carbon from used tires by the processes of carbonization and activation with superheated steam and carbon dioxide in a fixed bed reactor with the diameter of 100 mm. The used tires were carbonized at 350 ํC for 60 min with the air flow rate of 0.52 nl/min. The characteristics of the resulted chars were yield of 41.40%, fixed carbon of 62.57%, ash of 15.30% and volatile matter of 22.13%. Then, the chars were activated with superheated steam and carbon dioxide. The optimum condition for activation was 0.60-1.18 mm of the chars size at 900 ํC for 45 min with air at a flow rate of 0.27 nl/min, carbon dioxide at a flow rate of 2.0 nl/min and superheated steam. The resulted activated carbon obtained yield of 27.99%, bulk density of 0.3590 g/cm3, ash of 21.05%, iodine number of 598.79 mg/g, methylene blue number of 247.08 mg/g, B.E.T. surface area of 658.75 m2/g, micropore area of 424.27 m2/g, external area of 234.48 m2/g and average pore diameter of 22.24 A