CHEMICAL ACTIVATION OF ELUTRILITHE PRODUCING CARBON-ALUMINOSILICATE COMPOSITE ADSORBENT

A new adsorbent was prepared by chemical activation of elutrilithe with potassium hydroxide. A systematic study of the effect of the synthesis parameters, the mixing ratio of KOB/elutrilithe, activation temperature and time, on the final products was investigated. The prepared samples were subjected to benzene adsorption at room temperature for characterization by the Dubinin-Radushkevich (DR) method for the estimation of micropore volumes, pore widths and adsorption energies. Several samples were also characterized by analyzing the nitrogen adsorption isotherms at 77 K to estimate surface areas and total pore volumes. The moisture, carbon and ash content in the adsorbents were determined by thermogravimetric analysis (TGA). The influence of the treatment temperature on the surface structure was studied with Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS). It is concluded that high KOH ratios and relatively high temperatures favour the adsorption capacity, whereas long activation times lead to a widening of the micropores. A large capacity adsorbent with a N-2-BET surface area of 1121 m(2)/g and a total pore volume of 0.589 cm(3)/g was prepared. The new adsorbent exhibited larger adsorption capacities for benzene, toluene and xylene than two commercial activated carbons.