Study On Preparation Of Cornstalk Composite Carbon Material And Its Application In Desulfurization

With the continuous development of agriculture in our country,how to deal with a large amount of cornstalk waste has become the focus of attention.In recent years,due to the limitations of the traditional incineration and landfill methods,more and more people try to find other ways to dispose of the cornstalk.Cornstalk can be made into carbon materials and then used for adsorbing H₂S and other odors,which is a kind of new environmental protection method.This method can realize cornstalk resource utilization and achieve the purpose of waste treatment.In this paper,cornstalk was used as raw material to obtain stalk carbon material under the condition of chemical activation.Through single factor experiment,the optimum producing condition of stalk carbon was conducted and the adsorption properties of H₂S were tested.The results showed that there was no significant difference in the adsorption of H₂S on the carbon materials prepared by the cornstalk skin,core and mixture.Under the condition of activation temperature of350 ℃,the ratio of material to liquid of 1:2,and the activation time of about 70 minutes,the H₂S adsorption time of stalk carbon was up to 80 minutes.The structure analysis showed that there was no significant change in the composition of the surface functional groups of the activated carbon with or without activator.However,the specific surface area of stalk carbon increased significantly,and the micropore played an important role in the H₂S adsorption process.H₂S mainly exists in the form of elemental S and sulfite,which was in conformity with the dissolution-adsorption mechanism of activated carbon.The presence of oxygen containing functional groups on the surface of stalk carbon also played a major role in the catalytic oxidation of H₂S due to the ether functional group（C-O）.In order to further improve the desulfurization activity of stalk carbon,thestalk carbon was modified by copper in precipitation and impregnation ways.The results showed that the best desulfurization effect in the precipitation method was the sample obtained under the copper content of 25 % and the calcination temperature of 300 ℃,and the adsorption time of H₂S was up to 230 minutes.In the impregnation method,when the copper content was 15 % and the calcination temperature was about 300 ℃,the desulfurization efficiency of the modified carbon reached the best H₂S adsorption time of 130 minutes.The results showed that both the two methods had Cu O formation at low temperature.Under the condition of high temperature,Cu O would decompose and generate Cu2 O and elemental Cu.In order to make cornstalk carbon more practical value,the CMC binder was used to study the molding process.The results showed that when the molding pressure was 20 MPa,temperature was 250 ℃ and the content of CMC was 20 %,the samples showed the best desulfurization ability,with its adsorption time of 60 minutes and molding strength of 29 N·cm-2.The pore structure of the samples was basically unchanged after molding,and the functional groups on the surface of stalk carbon were not changed.It can be used in industrial production.