The Study On The Fabrication Of Iron-supported Phenolic Resin-based Activated Carbon And Removal Of Hydrogen Sulfide

Iron-supported phenolic resin-based activated carbon was prepared by blending iron nitrate into water soluble phenol-formaldehyde resin before carbonization and physical activation with CO₂ as activator.The optimal parameters of preparation process were systematically investigated.This modified activated carbon was used as desulphurizer in a fixed-bed reactor.The effects of the fabricating factors,such as amount of loaded iron,CO₂ flow and activation time on the structures obtained,which was used in oxidation of H₂S were studied and the desulfurization mechanism was discussed.The as-prepared activated carbon were characterized by X-ray diffraction(XRD),thermogravimetric analysis(TGA), fourier-transform infrared spectroscopy,(FTIR),scanning electron microscopy(SEM)and N₂ adsorption.The results are summarized as follows:With the iodine value as a definition of evaluation,the optimal parameter of fabrication of the iron-supported phenolic resin-based activated carbon was as follows:activation temperature of 850℃,activation time of 1.5 h,CO₂ flux of 30 mL.min^-1and loaded iron of 5%.This optimal factor was validated by the experiments of desulphurization under the constant condition of the ambient temperature,space velocity of 21500 h^-1,inlet H₂S concentration of 450 ppm,oxygen-contained of 3%and relativity humidity of 20%.The activated carbon prepared with optimal parameters shows best desulphurizaiton capacity under this condition.The sulfur removal capacity reaches as high as 37.8 mg·g^-1.The products can be regenerated by N₂ at high temperature and the catalytic oxidization activity of H₂S is still preserved after regeneration.The properties of the activated carbons before and after fine desulfurization were characterized by XRD,nitrogen adsorption at low temperature and TGA.The results shows that sulfur in an amorphous state,as major oxidation product,is deposited in the pores of the iron-supported phenolic resin-based activated carbon,which significantly decreases pore volume.Mesopore volume with a pore width of 4 nm decreases greatly after desulfurization. The results of experiments showed that the special mesopore formed from the activation reaction with CO₂ catalyzed by iron,and the iron supported on the surface of the activated carbon,as the active center might both enhance the catalytic activity for oxidation of H₂S.We also have reported the fabrication of one-dimensional rare-earth-compound nanomaterials including Nd(OH)₃,Pr(OH)₃)and SmPO₄ One-dimensional nanorods of neodymium hydroxide(Nd(OH)₃)have been synthesized by a hydrothermal technique using neodymium oxide(Nd₂O₃)powders as starting material in the absence of any surfactants,The products were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM) and transmission electron microscope(TEM).It reveals that the reaction temperature,pH value,monomer concentration of starting material and reaction time have great influence on the morphological evolution of the final products.Crystalline Nd(OH)₃ nanorods with high purity(over 90%)and good structural uniformity could be mass produced at 180℃for 12 h in a solution system with pH value of 9.5 and concentration of neodymium of 0.12 moL·L^-1. After the calcination of neodymium hydroxide nanorods at 500℃in air,the C-type neodymium oxide nanorods with bcc structure were obtained.In addition,one-dimensional nanowires of samarium orthophosphate(SmPO₄)have been synthesized by a hydrothermal technique using industrial samarium oxide(Sm₂O₃)powder as starting material in the absence of any surfactants.The products were characterized by X-ray diffraction(XRD)and transmission electron microscope(TEM).The results show that the reaction temperature,pH value,reaction time all could affect the morphology and size of the samarium orthophosphate nanowires.