Synthesis of zeolite X/activated carbon composites from rice hulls

Zeolite X/activated carbon composites were synthesized from rice hulls. The granules were made by mixing crushed rice hulls and sodium aluminate. The cellulose in the granules was converted to activated carbon by carbonization and activation processes. By a hydrothermal reaction, the activated granules were converted to zeolite X/activated carbon composites. The nitrogen adsorption and desorption isotherins of the zeolite X/activated carbon composites showed a combined shape isotherin of types I and IV. The specific surface area of the composite was 620 m(2) g(-1), the total pore volume was 0.39 cm(3) g(-1), and the pore size was 3-4 nm.