Study On Preparation Of Activated Carbon From Waste Cotton Textiles By K₂CO₃ Chemical Activation

With the economic development,people's pursuit of quality of life and the rapid development of the textile industry,resulting in a large number of waste textiles.Most of the waste textiles are landfill and incineration,only a small amount of recycling,not only caused the waste of resources but also pollute the environment.In this paper,a new way to recycle waste cotton textiles was put forward,namely activated carbon material prepared by chemical activation of spent cotton textiles.In this paper,activated carbon from waste cotton textiles was prepared by K₂CO₃ activation method.The conditions of carbonization and activation were investigated,and the characterization of waste cotton textiles and activated carbon was studied by means of SEM,BET,FTIR and XRD.The optimal carbonization conditions of carbonized activated carbon were as follows:carbonization temperature 300?,heating rate 4?/min,charring time 50min,the iodine adsorption value of activated carbon sample prepared under carbonization condition was1415.27mg/g,the yield was 26.13%.After carbonization,part of the cotton fibers break,the surface shape of the carbon fiber is conducive to the impregnation of the activator.The carbonized material has initially formed a compact carbon skeleton structure,the surface contains a variety of functional groups.The influence of process factors on the activation of activated carbon in waste cotton textile was that the iodine adsorption value increased first and then decreased with the increase of activation temperature,the increase of immersion time,the time of immersion and the activation time.The results showed that the iodine adsorption value decreased first and then increased with the increase of heating rate,and the yield decreased continuously.P-B was used to select the main factors of activation:activation temperature,impregnation ratio,activation time.Central composite design was used to establish the equation model of iodine adsorption value and yield.After optimization by equation model,the optimal activation conditions were obtained.The activation energy was 820.24?,the impregnation ratio was 0.96,the activation time was 1.56h,and the temperature was raised.The activation temperature was 820.24?,the impregnation ratio was 0.96,and the activation time was 1.56h.The results showed that iodine adsorption rate and yield prediction were1460.51mg/g and 15.9%,respectively,and the actual test values were 1513.7mg/g and15.02%,respectively.The predicted values were 3.51%and 5.5%respectively.The content of C in the activated carbon of waste cotton textile is up to 93.45%.The morphology of cotton fiber is still in the middle cavity structure,accompanied by different degree of distortions,and its outer surface is distributed with a large number of elliptical pores.The specific surface area of activated carbon is 1624.79 m²/g,the average pore size is 2.57nm,the pore volume accounts for 68.3%of the total pore volume,microporous activated carbon;its surface group content is small,amorphous graphite microcrystal structure appears.The surface area of the activated carbon is small,and amorphous graphite microcrystals structure.