Investigation Of Supported HPW On Carbon Material For Water Resistance In The Process Of NO Oxidation Removal From Flue Gas

A haze lay over the whole china in January of2013, so people focused on PM2.5again. Sulfate, nitrate and secondary organic aerosols which resulted from sulfuroxides, nitrogen oxides and volatile organic compounds （VOC） from flue gas ofcoal-fired power plants in the air led to the significant increase of PM2.5. If the fluegas didn’t been handled effectively, these factors would be the source of PM2.5.Referring to the situation that the desulfurization process of flue gas has been matureand applied effectively into practice in many years, the urgent way to find a roadwhich is suitable for china economic development is to research a series of economicefficient and green denitrification process.Selective catalytic oxidation （SCO） as a new denitrification process of flue gashas attracted wide attention because of its advantages: low energy consumption andhigh efficiency process. The major difference between SCO process and traditionalSCR process is that the former oxidize NO to NO₂with the help of catalysis and O₂inthe flue gas. What’s more, the super clean flue gas from power plant after the processof SCO would be applied to farm microalgae in order to produce bio-diesel. Thistechnology used effectively the waste heat and exhaust of power plant, and ultimatelyproduced an economic product. In view of the poor water tolerance during the courseof denitrification by carbon materials, the paper mainly studied the effect of watervapor on catalytic active and found several ways to solve this difficult problem. Themain work and results are followed as:The NO_xremoval technology and the problem of carbon materials during thecourse of denitrificaiton were briefly discussed. The principle of selective catalyticoxidation and NO_xadsorption catalyst for flue gas were systematically analyzed.The HNO3oxidation, base modification, and high temperature treatment were applied to improve water tolerance of activated carbon. The result showed:unmodified activated carbon performed poor ability to remove NO_xno matter whetherwater vapor exists in the flue gas; the conversion of NO of the catalysts by HNO3oxidation was low even though these exhibited relatively good water tolerance; basemodification was more beneficial to improve the efficiency of NO_xremoval thanHNO3oxidation, the effect of solution concentration and bake temperature onimproving denitrification efficiency of catalysts by NaOH was low concentration andtemperature while this effect for KOH was opposite, and the sample by the treatmentof KOH was more active; High temperature treatment wasn’t valuable to improve thewater tolerance; the two-step treatment was worse that one-step treatment. And then,the result of the content of surface acid and base functional groups showed that theconnection between water tolerance of denitrificaiton and the content of surface basefunctional groups wasn’t simple linear function.The different loading of HPW/C was prepared in order to improve the watertolerance during the course of denitrificaiton. At the same time, differentcharacterization methods were used for special aspects. The result showed thatHPW/C catalyst performed much more excellent water tolerance, especially10%HPW/C stood the top one whose efficiency of NO_xwas40%; the distribution of HPWin the support was highly homogeneous and HPW didn’t change the structure ofsupport; HPW molecular was more likely to enter into inner pore of the support whenthe loading was low; the Kegging structure of HPW didn’t change before and after thereaction, and HPW inhibit the generation of nitro and nitroso.10%HPW/C was carried on as catalyst to study the effect of different operatingparameters on water tolerance during the course of denitrification. The result showedthat the optimum process condition: reaction temperature120℃, oxygen content8%,water content6%, space velocity1000h^-1.The influences of reaction time, reaction temperature, loading content, and thesort of solution on the catalytic dissolution were studied. The result showed that thedissolution content were ignored from the factor of gas reaction; the catalyticdissolution increased in a quick speed in1h, and then it kept calm; the higher temperature of solutions, the lower the catalytic dissolution; the lower loading contentof HPW, the more obvious the dissolution; the higher concentration of HNO3wasbeneficial to result in the dissolution of HPW, ammonia was opposite.At last, semi-coke was choosed as support. The result showed that the influenceof water vapor on semi-coke was significant than activated carbon; HNO3oxidationand high temperature treatment couldn’t deal with this problem; when the loadingcontent of HPW was10%, the efficiency of NO_xremoval kept80%.