Enhanced SO2 and Rhodamine B Removal by Blending Coke-Making Waste Benzene Residue (BR) for Pelletized Activated Coke (PAC) Production and Mechanisms

An economical and efficient way to prepare pelletized activated coke (PAC) is to utilize coking byproduct (coke powder and benzene residue (BR)). In this work, carbon precursors were prepared at 600 degrees C by adding different amounts of BR (2, 4, 6, 8%) to the mixture of blending coals and coke powder, followed by activation of steam to obtain PAC with high surface and hierarchical porous structure. It was found that BR could adjust PAC's pore structure and surface chemistry and further influence its adsorption performance. The specific surface area of the PAC modified by the addition of 4% BR is up to 782 m(2)/g, which is 10.3% higher than that of the unmodified PAC. The regulation mechanism of BR on PAC's physicochemical structure was proposed. An obvious improvement of SO2 adsorption was also observed. The sulfur capacity of PAC modified by 8% BR is 58.7 mg/g, which is 17.4% higher than that of the unmodified PAC. Moreover, PAC modified by the addition of 4% BR shows that its rhodamine B (RhB) adsorption capacity was up to 109.8 mg/g, which is 32.6% higher than that of the unmodified PAC. Moreover, this research shows that BR is a potentially effective modifier for PAC; it could not only improve the performance of the PAC but also utilize the coking byproduct.