Properties Study Of Adsorption Of VOCs By Physical Activation Biochar

In recent years,the government begins to focus on ambient emissions and its governance issues of Volatile Organic Compounds,also called VOCs,and various processing methods and technology have been put forward including activated carbon adsorption treatment technology,meanwhile agricultural waste disposal has been always a problem.This paper starts from the pyrolysis of agricultural wastes to prepare the precursor of the activated biochar-biochar,and mainly focus on the preparation of activated biochar as well as its adsorption properties for VOCs.To combine the agricultural waste management and VOCs governance together,and explore the possibility of activation biochar as a kind of substitution of coal based activated carbon as adsorbent.In this research,the steam activation and carbon dioxide activation were investigated.In steam activation,we mainly focus on influences of different mass ratio of water to biochar for the adsorption ability.In carbon dioxide activation,we mainly focus on temperatures' influences for adsorption ability and types of biomass' influence.We conducted experiments such as determination of apparent density,initiative adsorption,passive adsorption,determination of Iodine numbers,and determination of surface oxygenic functional groups.Here some consequences as followings:1.apparent density of physical activation biochar is(0.2±0.02)g/mL.2.In initiative adsorption experiments,the best activated biochar MPCL 1-1 could reach 54.80mg/g while the MPCL 6-1 was 22.90mg/g.3.The amount of adsorption of VOCs went down from 17.8mg/g to 6.2mg/g with the temperature went from 750? to 850?.4.The same type activated biochar has different adsorption ability for different types of VOCs.The R2 of Pseudo first order kinetic mode were between 0.956-0.998.5.Boehm titration experiments showed that in the steam activation process there would be no phenolic hydroxyl group existing in the surface of activated biochar.6.Iodine numbers' results showed that MPCL 1-1 is the best activated biochar produced by physical activation.Because the coal based activated carbon uses the coal as precursors which is a kind of non-renewable energy resources,the activated biochar has wide application prospects in the place of coal based activated carbon.