Research On Preparation Of Coal Based Activated Carbons

In this paper, activated carbons (ACs) with high surface area were prepared from two different coals by a one-step process in which preoxidation and activation involved, and effects of process conditions on preparation of ACs were investigated. The results indicate that pre-oxidation process of C/D can obtain excellent ACs, the content of D also has a considerable influence on the adsorption property of ACs, and the ratio of K/C in weight can explicitly explain the transformation of porous structure of ACs.On the basis of betch-scale testing results,0.2 kg/d coals were treated in the rotary furnace made and designed by ourself, we can obtain ACs with specific surface area higher than 1800 m2/g, carbon yield higher than 50% and ash content less than 2% at activation temperature less than 800℃, activation time less than 90 min, and the ratio of KOH/Coals less than 2.5/1.The surface area and pore size distribution of ACs were characterized by the physical adsorption of nitrogen gas at 77 K, we found that the activated carbon samples with high surface area of 2036.04m2/g and pore size distribution between 0.64-2.93nm, were obtained at 900℃for 90 min. And also many oxygen-containing functional groups have been detected in the surface oxides of the samples by means of Boehm titration, FITR and ultimate analysis.Besides, the cyclic voltammetry analysis, constant current charge-discharge test and the charging-discharging curves indicate that the samples display the ideal capacitor behavior, and the adsorption capacities of ACs for benzene vapor were studied, implying that the sample was an effective adsorbent material.Consequently, coal with high sulphur, has shown enormous potential value as a precursor for new carbon materials, because of its unique character of high volatility, high caloric value, high reactivity, and including plenty of hydrogen or iron elements.