Preparation And Adsorption Performance Of Resin-based Activated Carbon Spheres

Activated carbon sphere(ACS)is a kind of porous carbons simultaneously having developed microporosity and high mechanical strength,which could overcome the main drawbacks of traditional activated carbons,such as low strength and low wear-resistance.Thus ACSs have great potential in applications of blood purification,adsorption and catalysis,et al.In this thesis,resin-based ACS were successfully prepared by sulfonation of macroporous polystyrene-based cation exchange resin spheres,followed by carbonization and various kinds of activation.The effects of activation processes on the pore structure of ACSs were systematically investigated.In addition,the vitamin B12 adsorption performance of these ACSs prepared by different activations were compared.The main conclusions were summarized as follows.1.The carbonization yield of resin spheres was determined strongly by the sulfonation degree,which was affected by many sulfonation processing factors,including the concentration of sulfuric acid,the mass ratio of sulfuric acid to resin spheres,the sulfonation temperature and the sulfonation time.The optimized mass ratio of sulfuric acid to resin spheres was determined to be 8 while using 50%fuming sulfuric acid at 80 "C for 16 h.The resultant sulfonated spheres had a high the sulfonic acid groups of 5.5 mmol/g and a high carbonization yield of 43.3%.2.ACSs were firstly prepared by a conventional steam activation method.The BET surface area and pore volume of ACS could be controlled in a wide range of 1021-1634 m2/g and 0.72-1.21 cm3/g,respectively,by adjusting the activation time and the flow rate of steam.It was found that the BET surface area as well as microporous and mesoporous volumes were gradually increased with the increasing activation time.3.ACSs with high mesoporous volume could be prepared by a H3PO4 activation method.It was found the activation conditions could affect more seriously on the mesoporous structure.While the impregnation ratio of H3PO4 to sulfonated spheres was 2 and the activation temperature was 750?,the as-prepared ACS had a high BET surface area of 1438 m2/g,large total pore volume of 1.38 cm3/g and very high mesoporous volume of 0.77 cm3/g.4.ACSs could be also prepared by a ZnCl2 activation method.The BET surface area and the total pore volume of as-prepared ACS were controlled in a range of 838-1921 m2/g and 0.69-1.1 8 cm3/g,respectively by changing the activation temperature and impregnation ratio.Also,the BET surface area,total pore volume and micropore volume were increased with the increasing impregnation ratio.5.The vitamin B12 adsorption performances over these ACSs prepared by different activation methods were investigated.All adsorption isotherms fitted well with Freundlich isotherm model,and the adsorption kinetics could be well described by pseudo-second-order kinetic equation.More importantly,the more mesoporous volume ACSs had,the higher adsorption capacity ACSs achieved.This result suggested the H3PO4 activation method should be the better method to prepare ACS with high adsorption performance.