Preparation Of Super Pore Volume Mesoporous Activated Carbon And Activated Carbon Fiber By Biomass

In this work, mesoporous activated carbons (ACs) with super huge pore volumes wereprepared from waste wood powder by ZnCl2activation process. Nitrogen adsorption, SEMand TEM were used for the characterization of ACs. The ACs adsorption behaviour ofVitamin B12(VB12) was studied. Activated carbon fibers (ACFs) were also obtained fromcotton by ZnCl2activation process. The influence of experimental conditions on thepreparation, pore structure, morphology, and structure of ACFs were studied. The main resultsare summarized as follows.(1) Mesoporous activated carbons (ACs) with super huge pore volumes could beprepared from pine wood powder by ZnCl2activation process. The specific surface area was1647m2/g, pore volume was as high as3.56cm3/g, and the average pore diameter was2.5—8.6nm. The present method could be applied for many other type of trees for thesynthesis of mesoporous activated carbons. The obtained ACs could have specific surface areaof1400-1600m2/g, huge pore volume of3.5-4.5cm3/g.(2) The amount of ZnCl2had important influence on the pore properties of ACs. The roleof ZnCl2was not only to create micropores, but also to form mesopores by enlargingmicropores. The main role was determined by the ZnCl2mass used in the ACs preparationprocess. The reason why mesoporous activated carbons (ACs) with super huge pore volumescould be prepared in this work was because a extremely huge ZnCl2mass was used in thepresent work, which was never appeared in the previous literatures.(3) mesoporous activated carbons with large pore volume had excellent adsorptionproperties of VB12. The maximum adsorption amount of VB12for AC-50was600mg/g,which was nearly equal to the maximum theoretical adsorption capacity (625mg/g). VB12adsorption amount of ACs increased with VB12concentrations, decreased when raising thetemperature. VB12adsorption amount was not influenced obviously by solution pH values.The adsorption kinetics of VB12could be described by the Langmuir equation, whichsuggested that VB12adsorption on ACs was close to monolayer adsorption behaviour.(4) Activated carbon fibers could be prepared from cotton by ZnCl2activation process. the optimum experimental conditions was that, the carbonization temperature400-500℃,ZnCl2concentration of10-20%. The obtained product could have the specific surface area of800-1600m2/g and pore volume of0.4-0.8cm3/g.(5) Both activation temperature and ZnCl2concentration had important influence on themorphology and pore structure of activated carbon fibers. The ACFs surface area and porevolume could be increased by elevating activation temperature. Increasing ZnCl2concentration could significantly increase the surface area and pore volume of ACFs, butcould destroy the fibrous morphology of the product.