Study On Green Desulfurization System Based On Efficient Removal Of Hydrogen Sulfide And Recycling Of Heteropoly Compounds

Hydrogen sulfide is a colorless gas with toxic,corrosive and rotten egg smell.It mainly exists in nature and industrial production activities.Hydrogen sulfide will not only increase the cost of converting valuable energy or chemical products such as natural gas and syngas,but also destroy the ozone layer,cause serious Greenhouse Effect,and cause serious damage to human eyes,respiratory system and crops.In this study,in order to solve the problem of malodorous gas Hydrogen sulfide released in the production process,three new green desulfurization systems were constructed,namely,W and V substituted heteropoly compounds/aqueous solution system,Keggin type[Himi]SMo heteropoly compound/aqueous solution system with sulfur as central atom,and transition metal substituted ionic liquid heteropoly compound/ionic liquid system.Different kinds of multicomponent heteropoly compounds(HPC),were investigated in detail.The HPC with high desulfurization efficiency was selected and the best desulfurization conditions were investigated.The mechanism of desulfurization and regeneration was analyzed by FT-IR,XPS and other analysis methods.In the first system of this paper,a series of W,V substituted heteropoly compounds were prepared by hydrothermal synthesis,which were used in the removal of hydrogen sulfide using water as solvent.The structure and composition of heteropoly compounds were analyzed by FT-IR and elemental analysis.Comprehensive comparison of hydrogen sulfide absorption and regeneration experiments.The results showed that the desulfurization performance of vanadium substituted heteropoly compounds was the best,and hydrogen peroxide,potassium permanganate and potassium periodate enhanced the desulfurization effect.The effects of pH,current intensity and regeneration time on the performance of the regenerated desulfurization solution were investigated by electrochemical regeneration.The results of the samples before and after the reaction show that the desulfurization product contains sulfur element.In the second system of this paper,the role of central atoms in POMS was studied from the point of view of oxidative removal of Hydrogen sulfide.A series of heteropoly compounds with different central atoms[Himi]XMo(X=S,P,Ge)were prepared,and the desulfurization properties of desulfurizers under different reaction conditions were investigated.The FT-IR spectra confirmed the successful synthesis of(Himi)2[XMo12O40](X=S,P,Ge).By analyzing the cyclic voltammetry curve and investigating the desulfurization performance of the desulfurizer,it is found that the polyacid molecule with higher central atomic electronegativity has stronger activity and higher hydrogen sulfide capacity than the analogue with lower central atomic electronegativity.The desulfurization results show that the removal rate of Hydrogen sulfide in water by[Himi]SⅥMo can reach more than 90%,and the capacity can reach 627 mg/g,and can be further increased to 2174 mg/g after electrochemical treatment.Through further characterization of XPS and FT-IR,the mechanism of oxygen participating in POM in-situ reoxidation and Sapot O exchange on POM molecules was proposed and verified by experiments,and the reason for the high sulfur capacity was reasonably explained.This work provides recorded Hydrogen sulfide capacity materials and new guidance for the reasonable design of high performance POM desulfurizer.In the third system of this paper,a new type of heteropoly compound which combines transition metal and ionic liquid is constructed,and the desulfurization system using ionic liquid as solvent is constructed.In this study,ionic liquids play a role in dissolving heteropoly compounds and improving thermal stability.According to the comprehensive comparison of the desulfurization effect,it is known that the desulfurization effect of[Emim]PMoCo/[Emim]OAC is the best.The desulfurization performance of[Emim]7PMo11CoO39/[Emim]OAC at high temperature is better than that of heteropoly compound aqueous solution at room temperature.The effects of various conditions on the desulfurization ability were investigated.The experimental results show that the higher the removal rate of hydrogen sulfide is,when the temperature is 140℃,the concentration of heteropoly acid is 0.004 mol/L,and the concentration of hydrogen sulfide is 2000 mg/m3.The adsorbents and desulfurization products were characterized by elemental analysis,FT-IR,TG-DTA and XPS,and the desulfurization products and desulfurization mechanism were analyzed in detail.In the process of desulfurization,the Co and Mo atoms,Co(+Ⅲ)in[Emim]7PM011CoO39 samples change to Co(+Ⅱ),Mo(+Ⅵ)to Mo(+Ⅳ).After air stripping and regeneration,Co in the sample is reoxidized to Co(+Ⅲ),Mo is reoxidized to Mo(+VI),XPS analysis results show that the final desulfurization product contains sulfur and sulfate.