| In this paper,corncob was used as raw material,firstly,furfural was prepared by acid hydrolysis of corncob with sulfuric acid as catalyst,and further,the prepared furfural was used as raw material for catalytic pyrolysis.Aromatics were prepared by catalytic pyrolysis of furfural with HZSM-5 zeolite molecular sieve as catalyst.The maximum yield of aromatics can be achieved by adjusting the conditions of pyrolysis temperature,injection rate,Si/Al ratio of catalyst(Si/Al)and carrier gas(N2)flow rate.Part of the mechanism of action of the catalyst and the conditions for obtaining the highest conversion of aromatic hydrocarbons were analyzed.HZSM-5 zeolite treated with 0.9mol/L hydrochloric acid when the used catalyst Si/Al = 23,the pyrolysis temperature was500 ℃,the carrier gas flow rate was 10 ml/min,and the furfural injection rate was 0.5ml/h Molecular sieve catalyst catalyzed the pyrolysis of furfural to obtain the highest carbon conversion of benzene,toluene and xylene(BTX),and the highest carbon yield of BTX was 30.85 %.The ratio of Bronsted acid sites on the catalyst surface was found to affect the selectivity of the zeolite molecular sieve catalyst to BTX in the liquid phase product during catalytic pyrolysis.Design synthesis of catalysts.Different templates were selected to test the synthesis and catalytic effect of molecular sieves.Among them,the Ni Cl2 group of catalysts had the highest selectivity to BTX.A series of molecular sieve catalysts were synthesized by changing the amount of template agent,and the surface morphology and physicochemical properties of the catalysts were characterized and analyzed.The results showed that 3.0 %Ni Cl2 molecular sieve had the highest content of Bronsted acid sites and the lowest Lewis acid sites.Through catalytic pyrolysis experiments,it was found that when the addition amount of Ni Cl2 was 3.0 %,the carbon yield of BTX obtained by catalytic pyrolysis of molecular sieve catalyst was 33.02 %,which improved the BTX selectivity.Biomass-based functional carbon materials were prepared by a two-step "carbonization-activation" method using corncob hydrolyzed residual furfural residues as raw materials.When the carbonization temperature is 400 ℃,the activation temperature is 800 ℃,and the mass ratio of KOH activator to carbon is 1:1,the obtained carbon material has the best microwave absorption performance,and has a certain microwave absorption performance in multiple bands at different thicknesses.At a filling ratio of10 % and a thickness of 3 mm,the reflection loss is as high as-61.27 d B,the bandwidth is 2.60 GHz,and it has microwave absorption performance in both X-band and Ku-band.At a thickness of 2.5 mm,the maximum reflection loss is-32.09 d B,the bandwidth is3.12 GHz,and the absorption rate of the X-band microwave is as high as 78 %.Made with pecan shells.Experiments show that the best microwave absorption performance is obtained when the carbonization temperature is 400℃,the activation temperature is 800℃,and the mass ratio of KOH to carbon is 3:1.At a filling ratio of20 %,the maximum return loss is-47.20 d B,and the bandwidth is 2.0 GHz.The microwave absorption effect is lower than that of functional carbon materials prepared from furfural residues.The comprehensive grading and utilization of corncob is realized by liquefaction and residue treatment of corncob.Figure [32] Table [19] Reference [128]... |
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