| A variety of industrial carbon monoxide tail gases contain reducing phosphorus,sulfur,and cyanide.Synchronously deep purification under reducing atmosphere can not only effectively eliminate pollution to the environment,but is key technology to achieve resourcilization of carbon monoxide tail gas.Mixed-gases purification technologies in the past are based on unit operation techniques of purification of single component respectively.Higher investment,more complex operation requirements and higher operating costs become the bottleneck problems that limit the technology popularization and application.The successful development of technology that can purify phosphorus,sulfur,and cyanide synchronously and selectively in the moderate reducing atmosphere(10?85?)will undoubtedly have important significance for promoting the use of tail gas purification technology and recycling.Considering the obvious advantages of the liquid phase catalytic oxidation,such as high activity,good selectivity,and mild reaction conditions and the problems in the liquid phase catalytic oxidation,such as low solubility of oxygen,the difficulty of separating catalytic oxidation products from the catalysts and simultaneous catalytic purification of complex impurities.The study will use a novel liquid phase catalytic oxidation method which is enhanced by electrochemistry for purification of PH3,H2S,and HCN in yellow phosphorus tail gas with the flowing three aims:(1)to screening liquid-phase catalysis which show catalytic activity for PH3,H2S,HCN;(2)to explore the synergy between electrochemistry and the liquid phase catalysis and the interaction of PH3,H2S,HCN during synchronous purification process;(3)to develop new reactors and technology of synchronous efficient and selectivepurification forPH3,H2S,and HCN.(1)In order to purify PH3,H2S,and HCN,we use electrostatic precipitator ash,red mud fluid,phosphate powder/paste,889 desulfurizer,Pd(?)-Cu(II),Pd(?)-Fe(?),etc.,as liquid catalyst.Purifying experiments illuminate that there are significant interaction and inhibition effects among PH3,H2S and HCN during the synchronous catalytic purification.(2)Use self-synthesized CuO/Fe3O4?TiO2/Fe3O4?Pd/TiO2/Fe3O4?Cun1Pdn2Ox/Fe3O4 etc.nanoparticles to purify PH3,H2S,and HCN respectively.Gas chromatographic analysis showed that CuO/Fe3O4?TiO2/Fe3O4?Pd/TiO2/Fe3O4?Cun1Pdn2Ox/Fe3O4 etc.nanoparticles can catalyze and convert HCN into CO2,N2(or NH3)under the condition of low temperature(10?85?).(3)Using self-designed electrodialysis experiment device and electrical-enhanced iron carbon micro-electrolysis reactor to purify PH3,H2S,and HCN.Ion chromatography,Infrared spectroscopy and Raman spectrum analysis show that electrolytic and electrical-assisted micro-electrolysis can effectively oxidized PH3into H3PO4,oxidized H2S into S/H2SO4and oxidized HCN into CO2,NO3-(or N2,NH3).(4)The purification experiment with electrolysis reactor illustrate that there exist transitional metal catalyst(metal ion or metal oxide nanoparticles)which can catalyze and oxidaze PH3,H2S and HCN simultaneously.And the removal ratio of PH3,H2S,and HCN can maintain 100%in 300min purification process.(5)Absorbing liquid containing H3PO4 and catalysts was treatment with inverted pole electrodialysis after synchronous catalysis and purification.As a result,H3PO4 and the catalyst can be effectively separated,and the synchronous purification efficiency of PH3,H2S and HCN in absorbing liquid back to 100%.During simultaneous purification of PH3,H2S,and HCN,multiple synchronous effects between electrolysis and liquid-phase catalysis is illustrated.Electrolysis can not only accelerate the absorption of HCN,but also dissociate sediment produced in the course of catalytic purification and promote the stability of transitional metal catalysts.On the condition that liquid-phase catalytic oxidation is promoted by electrolysis,the synchronous removal ratio of PH3,H2S,and HCN can remain 100%steadily. |
PDF Full Text Request