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ID:32332467
大小:5.19 MB
页数:90页
时间:2019-02-03
《hzsm-5分子筛在液化气芳构化反应中的催化性能-研究》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、万方数据太原理工大学硕士研究生学位论文加j从而微孔表面积和孔容减少,介孔比面积和孔容增加,催化剂的容炭能力增加,催化剂稳定性提高;同时适当的碱处理条件有效调变催化剂的强、弱酸和B、L酸协同作用增强,从而芳烃和液体收率较高。4)Zn改性催化剂的芳构化评价结果表明,1.57%Zrd(HZ—AT(120,O.2)竹一A1203)催化剂的芳构化活性最优。Zn改性催化剂表面的ZnO一方面会覆盖催化剂表面的部分强酸,另一方面ZnO作为弱酸存在,使催化剂的总酸量发生变化。随着Zn含量的增加,强酸量减少使烷烃初始活化能力减弱
2、,而弱酸量增加使烷烃脱氢作用和脱氢芳构化作用增强,芳烃收率提高;但Zn含量过大时,强酸量大幅降低,弱酸量大幅增加,会抑制烷烃初始活化,降低强、弱酸的协同作用,使芳烃收率下降。Zn含量为1.57%时,强弱酸的协同作用最强,芳烃收率最高。关键词:HZSM一5,Si/A1比,碱处理,锌改性,LPG,芳构化III万方数据太原理工大学硕士研究生学位论文IV万方数据太原理工大学硕士研究生学位论文STUDYONCATALYTICPROPERTIESOFHZSM一5INLPGAROM[ATIZATIONABSTRACTLiq
3、uefiedpetroleumgas(LPG)isakindoftraditionalcivilfuel,whichisgraduallybeingreplacedbynaturalgas.TheutilizationanddevelopmentofLPGisconsiderablesignificance.Inrecentyears,LPGaromatizationtechnologyprovidesanewopportunityforthedevelopmentandutilizationofLPGThe
4、objectiveproductsofLPGaromatizationarebenzene,toluene,ethylbenzeneandxylene(BTEX),whichhavenotonlybeenthemostnecessaryrawmaterialsinthechemicalindustry,butalsomaybetransformedintohigh—octanegasoline.Therefore,LPGaromatizationtechnologyiscontributedtoachieve
5、thereuseofLPGandimprovedthesupplyofaromatics.HZSM一5isusedascatalystinLPGaromatizationduetoitsthreedimensionalcrossingstraightchannelstructurewithten—memberedring,largesurfacearea,goodshapeselectivecatalyticperformanceandspecialsurfaceacidity.However,theHZSM
6、一5showedshortlifetime,whichlimiteditslarge—scaleindustrialapplications.Inthispaper,wemainlyinvestigatedtheconversionoftheindustrialLPGinaminiaturefixed—bedevaluationdevice.ThecatalyticpropertiesofdifferentSi/A1ratio,alkali—treatmentandZnmodificationonHZSM一5
7、+7一A1203onthelightparaffinaromatizationwerealsoinvestigated.Firstly,differentnSi02/nAl203ratiosofHZSM一5竹一A1203with38and50weremodifiedbyimpregnationmothedtopreparedZn/(HZ+r—A1203).Thenbasedontheaboveoptimalcatalysts,aseriesofHZ—AT(t)andHZ—AT(C)werepreparedby
8、alkalinetreatmentofNaOHaqueoussolutionwith30min,120minand300min,thenaddingbinderintothealkali—treatedHZSM-5,andtheirV万方数据太原理工大学硕士研究生学位论文catalyticactivitywasinvestigatedtosievethebestalkali—treatedtime.
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