【作者】 胡耀池；

【导师】 黄和；

【作者基本信息】 湖南科技大学 ， 应用化学， 2007， 硕士

【摘要】 随着全球性石油资源供求关系的日益紧张,油价不断上扬,同时石化工业所造成的环境污染日益严重,传统石油乙烯工业将面临新挑战。如何突破资源短缺的瓶颈,利用可再生生物质资源生产乙醇,再进一步脱水成乙烯,从而逐步替代传统的石油乙烯成为当前研究的热点。本论文主要以低温脱水催化剂为研究对象,重点研究了金属离子改性HZSM-5催化乙醇脱水制乙烯,得到一些有意义的结果。本文分别采用离子交换法和浸渍法制备了一系列金属离子改性的HZSM-5催化剂,比较了不同金属、不同改性方法对HZSM-5催化剂反应活性的影响,并从各方面考察了分子筛催化剂对乙醇脱水制乙烯的催化性能,及其重要的影响因素。其中,离子交换法中的金属主要为Fe、Mn和Co。结果表明Co-HZSM-5具有较好的催化活性,在温度493K、质量空速2.5h^-1、乙醇体积分数为60%的反应条件下,乙醇的转化率和乙烯的选择性分别达到99.67%和99.32%。对浸渍法改性,则主要考察了Mg、Ca、Sr、Ba、Mn、Fe、Co、Zn、Zr、Cd、La和Ce等金属中的单组分或多组分复合改性后的催化脱水效果。结果表明不同的金属离子、在不同负载量的条件下制备的催化剂的脱水性能差别很大,其中0.5%Sr/HZSM-5、1.0%Mn/HZSM-5、1.0%～2.0%Zr/HZSM-5、1.0%La/HZSM-5、0.5%Sr-0.25%La/HZSM-5、0.5%Sr-0.5%La/HZSM-5、0.5%Sr-1.0%La/HZSM-5和0.25%Sr-1.0%La/HZSM-5均具有较好的催化活性,在温度493K、质量空速2.5h^-1、乙醇质量分数为50%的反应条件下,乙醇的转化率和乙烯的选择性均大于98.00%。更多还原

【Abstract】 Due to the petroleum emergence of rising demand and decreasing supply,the price of petroleum was unavoidably increasing.Besides,the petroleum-based industry has already caused serious contamination to the global environment.As a result,a new route to substitute for the traditional chemical industry is cried for,especially in the production of ethylene,one of the most important platform compounds in the world.Nowadays much work has been done in this field.The focus is using renewable biomass as a raw material to produce ethanol,which is then converted to ethylene by chemical means.This paper concerned the dehydration of ethanol to ethylene over metal ions modified HZSM-5.In order to compare the dehydrating activity of HZSM-5 modified by different metals,a series of catalysts were prepared by both normal ion-exchange method and impregnation method.The metals for ion-exchange were Fe,Mn and Co.The results showed that Co-HZSM-5 had better performances in dehydration of ethanol.Under 493K, the best ethanol conversion of 99.67%and ethylene selectivity of 99.32%were obtained when WHSV and ethanol volume fraction were 2.5h^-1 and 60%respectively.Also,the influences of modified HZSM-5 using impregnation method with Mg,Ca, Sr,Ba,Mn,Fe,Co,Zn,Zr,Cd,La and Ce,were investigated in details.The results indicated that 0.5%Sr/HZSM-5,1.0%Mn/HZSM-5,1.0%～2.0%Zr/HZSM-5, 1.0%La/HZSM-5,0.5%Sr-0.25%La/HZSM-5,0.5%Sr-0.5%La/HZSM-5, 0.5%Sr-1.0%La/HZSM-5 and 0.25%Sr-1.0%La/HZSM-5 all had better performances in dehydration of ethanol.Under 493K,the best ethanol conversion of more than 98.00%and ethylene selectivity of more than 98.00%were obtained when WHSV and ethanol quality fraction were 2.5h^-1 and 50%respectively.更多还原