Regeneration of microwave assisted spent activated carbon: Process optimization, adsorption isotherms and kinetics

• Published in: Chemical engineering and processing Vol. 53; pp. 53 - 62
• Main Authors: Xin-hui, Duan, Srinivasakannan, C., Qu, Wen-Wen, Xin, Wang, Jin-hui, Peng, Li-bo, Zhang
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.2012; Elsevier
• Subjects: Adsorption; Adsorption isotherm and kinetic; Applied sciences; Basic dye; Chemical engineering; Exact sciences and technology; Microwave assisted regeneration; Optimization; Spent activated carbon; Adsorption isotherm and kinetic; Spent activated carbon; Microwave assisted regeneration; Basic dye; Optimization; Second order; Adsorption isotherm; Adsorption capacity; Microwave; Liquid phase; Water vapor; Modeling; Langmuir isotherm; Kinetic model; Microporosity; Adsorption; Activated carbon; Kinetics; Surface area
• ISSN: 0255-2701; 1873-3204
• DOI: 10.1016/j.cep.2011.12.011

► Spent coal based activated is taken to regenerate activated carbon. ► Response surface methodology is used to obtain an optimum experimental result. ► The activated agent of steam and is used in the experiment. ► The microwave heating is introduced for the regeneration of spent activated carbon. ► The maximum methylene blue adsorption capacity of activated carbon was 385mg/g. Microwave assisted regeneration of spent coal based activated carbon from the silicon industry has been attempted using steam as the regenerating agent. The response surface methodology (RSM) technique was utilized to optimize the process conditions and the optimum conditions have been identified to be a regeneration temperature of 950°C, regeneration time of 60min and steam flow rate of 2.5g/min. The optimum conditions result in an activated carbon with iodine number of 1103mg/g and a yield of 68.5% respectively. The BET surface area corresponds to 1302m2/g, with the pore volume of 0.86cm3/g. The activated carbon is heteroporous with a micropore volume of 69.27%. The regenerated carbon is tested for its suitability for adsorption of methylene blue dye molecule. The adsorption isotherms were generated and the maximum adsorption capacity was found to be 385mg/g, with the isotherm adhering to Langmuir isotherm model. The kinetic of adsorption was found to match pseudo-second-order kinetic model. The results indicate potential application of the regenerated activated carbon for liquid phase adsorption involving high molecular weight compounds.