等离子体一催化分解脱除NOx的研究

等离子体一催化分解脱除NOx的研究摘要NOx作为最主要的空气污染物之一，己经成为一个日益严重的全球性问题。所以，研究脱除NO、是目前富有挑战性的课题之一。脱除NOx的主要困难在于NO:的转化方向上，当然，使NO:分解成为NZ和O2是最有效的方法。分解脱除NO:的方法包括化学催化法和等离子体法。NOX的催化法脱除，目前虽然有了一定的工业应用，但是存在着转化率低、能耗大、催化剂寿命短、造价高等诸多问题，需要解决的问题还很多;而等离子体转化法，转化率还不高。等离子体和催化剂协同作用脱除NOX具有许多优点，是一条脱除NO:的新途径，介质阻挡放电反应是在常温常压下进行，脱除NO:具有能耗低、时间短、环境友好、操作简单、可控性强等优点。本论文的目的在于获取等离子体与催化剂协同作用脱除NO、的规律性认识，并探索降低能耗和提高转化率的有效途径。主要工作包括:(1)研制等离子体与催化剂协同作用的反应器;(2)研制转化NOX的催化剂:(3)优化转化NO:的工艺条件和电参数;(4)考察氧化性添加气对反应的影响:(5)对等离子体一催化作用机理进行探索。通过对实验结果的分析与讨论可得如下结论:1.以NJ-1载体为介质时，NO脱除反应的催化效果较好。2.负载金属型催化剂及负载金属氧化物型催化剂对NO脱除反应均有催化活性，经筛选得到M-0分别负载在NJ-1及x-A1}0:、上的催化活性为最好，NO脱除率分别达到90%及78%03.首次将M-0/NJ-1用于介质阻挡放电反应体系，进行分解脱除NO的研究，在常温常压下，注入功率为16W时，NO脱除率达到90%04.在反应体系中，以M-0/NJ-1为催化剂时，不同负载量的M-0对反应的催化活性有影响，起初随负载量增大而增大，负载量为20%左右时，催化剂的催化活性为最好，负载量继续增大时，催化活性反而下降。5.等离子参数(放电电压、等离子注入功率等)对NO的脱除有重要影响:工艺参数(反应气体空速、初始浓度、催化剂担载量等)对反应也有重要影响。6.在反应体系中添加一定量的氧化性气体OZ，不利于NO的脱除，但在添加Oz量为5%，注入功率为16W时，NO的脱除率仍然能保持在70%}为富氧条件下脱除NO创造了重要的研究条件。7.在反应体系中同时添加一定量的0}和水蒸气，不利于NO的脱除，加氧量为10%，水蒸气量为3.6%时，NO脱除率为51%08.等离子体一催化反应体系的作用机制:等离子体主要起着活化反应物分子的作用，而催化剂则起着选择生成物的作用。theDecompositionNOXunderf且0StudyonSynergismPlasmawithCatalystAbstractAsoneofthemostimportantairpolluters,NOxhasbecomeadeteriorativeproblem.ThestudyofremovingtheNOxishistoric.ThemethodsoftheNOxdecompositionarethechemicalcatalysisandplasmamethod.ButthedecompositionofNObythesynergisticactionofdielectricbarrierdischarge(DBD)plasmaandthecatalystsisoneofthenewmethodstoremovetheNOx.Inthispaper,theinfluencesofvariousexperimentalparametersofDBDandtheselectivityofcatalystswereinvestigatedindetail.Thecontentsaresummarizedasfollows:1.Researchandproducethereactorofsynergisticplasmawithcatalysts.2.Researchandproducethecatalysts,whichcanbeusedindecomposingNO.3.ResearchtheprocessconditionsandelectricparametersoftheremovalofNO.4.StudytheinfluencetothedecompositionofNObyaddingtheoxidativegases,suchasoxygenandwatervaporquantitatively.S.ExplorethemechanismofdecompositionofNO.Theresultsandconclusionsaresummarizedasfollows:1.WhenwetaketheNJ-1supportasdielectricsubstance,wegotthebestefficiencyofNO.2.Themetal-loadingcatalystsandthemetaloxides-loadingcatalystsactivatetheremovalofNO.WefoundthattheM-O/NJ-landM-O/Y-A1203arebest,theremovalefficiencyofNOis90%and78%.3.WeusedtheM-O/NJ-1ascatalystinthesystemofdielectricbarrierdischargeplasmafirstly.Attheroomtemperatureandatmospherepressure,whentheplasmapoweris16W,theremovalefficiencyis90%.4.TheloadingquantityofM-OontheNJ-1supportinfluentsthereaction.Atfirst,theremovalefficiencyincreasesastheloadingquantityincreases,whenitis20%,thecatalyticactivityisbest,butafterthis,theefficiencydecreases.S.Plasmaparameters(Voltage,Plasmapower,etc)areimportantinthedecompositionofNOx,aswellastechnologicalparameters(Reactantgas'sspeed,Airintake,Catalyst'sloadvolume).6.Theadditionofoxygenisinconvenienttothereaction,butwhentheadditionofoxygenis5%,theplasmapoweris16W,theefficiencyis70%,thisphenomenonisanimportantconditionforthemoreprogressivestudyoftheremovaloftheNOx.7.Whenweaddoxygenandwatervaporquantitativelyinthesametime,theremovalefficiencyofNOdecreases.Whentheadditionofoxygenis10%andthewatervaporis3.6%,theremovalefficiencyis51%.8.Thesynergismmechanisminthereactionsystemofplasmaandcatalystisthattheplasmacanactivatereactants,Whilethecatalystscanselectivelyimprovethepercentconversion.了目录摘要ABSTRACT第一章文献综述1.1实现NO:脱除的意义·..........................................................................11.2脱除NOx的方法·..................................................................................21.3固体吸附法·........................................................................................31.3.1分子筛吸附法·...........................................................................41.3.2活性炭吸附法·...........................................................................41.3.3硅胶及其它吸附剂吸附法·......................................................51.4液体吸收法·........................................................................................51.4.1水吸收法·..................................................................................51.4.2酸吸收法...................................................................................61.4.2.1稀硝酸吸收法·..........................................................61.4.2.2浓硫酸吸收法·..........................................................61.4.3碱液吸收法·..............................................................................61.4.4氧化吸收法·...............................................................................71.4.5液相还原吸收法·......................................................................g1.4.6液相络合吸收法·......................................................................g1.5催化还原法...........................................................................................g1.5.1非选择性催化还原法·..............................................................g1.5.2选择性催化还原法·.................................................................101.6催化分解法..........................................................................................111.6.1贵金属催化剂·..................................