稀土离子浓度对Y型分子筛传质动力学的影响

摘要

采用传统液相离子交换法制得不同稀土浓度的Y型分子筛(REY),运用频率响应(FR)技术和智能重量分析仪(IGA)研究了苯在REY分子筛上发生的传质动力学过程,从而研究稀土离子浓度对其吸附扩散过程的影响,并结合XRD、物理分析仪等表征手段对样品进行表征.结果表明,稀土的引入使吸附量逐渐减少,且适量稀土的引入可以提高其扩散传质性能,但是过量的稀土使其传质性能下降.苯在REY型分子筛上的传质过程存在着不同的吸附过程,适量稀土的引入可以提高催化和吸附分离工艺中分子筛对吸附质的选择性,从而提高催化和分离效率.%The Y-type zeolites (REY ) with different contents of rare earth ions were prepared by the traditional liquid-phase ion exchange method .The mass transfer kinetics of benzene on the REY zeolite was studied by using frequency response (FR) technique and intelligent gravimetric analyzer (IGA) .The effects of the concentration of rare earth ions on the adsorption and diffusion process were studied , and the samples were characterized by XRD , physical analyzer and other characterization methods .The results show that the adsorption capacity decreases with the introduction of rare earth ,and the introduction of appropriate rare earth can improve its mass transfer performance ,but excessive mass of rare earth decreases the mass transfer performance .The adsorption process of benzene on REY zeolite has different adsorption process .The introduction of rare earth can improve the selectivity of zeolite to adsorbate in the process of catalytic and adsorption separation ,so as to improve the efficiency of catalysis and separation .