甘油在γ-Al2O3负载杂多酸催化剂上气相脱水的研究

    GAS PHASE DEHYDRATION OF GLYCEROL CATALYZED BY Γ-AL2O3SUPPORTED HETEROPOLYACID

    • 摘要: 通过活性组分选择和载体改性设计催化剂,提高对甘油催化脱水反应的性能,同时研究反应条件对甘油转化率和丙烯醛选择率的影响规律。以 γ-Al2O3为载体,H3PO4、H4SiW12O40、H3PW12O40和H3PMo12O40为活性组分,采用初润浸渍法制备催化剂,研究了常压下甘油气相脱水生成丙烯醛的催化反应性能。结果表明,γ-Al2O3负载H4SiW12O40对甘油脱水生成丙烯醛有良好的催化性能。质量分数为20%的甘油水溶液以0.1 mL/min的速率进料,310℃时甘油转化率和丙烯醛的选择率分别为89.19%和83.61%。载体γ-Al2O3采用B2O3或ZrO2改性,可提高γ-Al2O3负载H4SiW12O40催化剂的催化性能。B2O3改性催化剂,310℃时甘油的转化率近100%,丙烯醛的选择率达85.32%。同时,对活性组分H4SiW12O40的适宜负载量、甘油水溶液质量分数、液体空速等也进行了考察。甘油水溶液质量分数为35%时,在20%HSiW 10%B2O3/γ-Al2O3催化剂上,液体空速为2.0 h-1,甘油完全转化,丙烯醛的转化率大于90%。

       

      Abstract: In order to improve the catalytic performance of catalysts on glycerol dehydration,the active components were selected and the support was modified in the present study.The influence of reaction conditions on the conversion rate of glycerol and the selectivity rate of acrolein was also studied.The catalysts were prepared by the initial wetness impregnation method,with γ-Al2O3as support,and H3PO4,H4SiW12O40,H3PW12O40and H3PMo12O40as the active components.The catalytic performance of the prepared catalysts on the gas phase dehydration of glycerol to acrolein under atmospheric pressure was examined.The results showed that γ-Al2O3supported H4SiW12O40had excellent catalytic performance on the dehydration of glycerol to acrolein.The conversion rate of glycerol and the selectivity rate of acrolein were 89.19% and 83.61% at 310℃,respectively,when 20% glycerol aqueous solution was fed at a rate of 0.1 mL/min.The γ-Al2O3modified by B2O3or ZrO2could improve the catalytic performance of γ-Al2O3supported H4SiW12O40catalyst.The conversion rate of glycerol was reached to 100% and the selectivity rate of acrolein was up to 85.32% at 310℃ with B2O3modified γ-Al2O3supported H4SiW12O40as catalyst.Furthermore,the effect of the load amount of H4SiW12O40,the concentration of glycerol aqueous solution and liquid hourly space velocity on the catalytic performance of prepared catalysts was also investigated.The optimal conditions were as follows:the concentration of glycerol aqueous solution 35%,20% HSiW10% B2O3/γ-Al2O3as catalyst and the liquid hourly space velocity 2.0 h-1,under which the glycerol in feed was almost completely converting to products and the selectivity rate of acrolein was higher than 90%.

       

    /

    返回文章
    返回