渣油加氢脱硫催化剂载体堆积密度的精确控制

摘要

Alumina carriers for residue hydrodesulfurization catalyst were prepared by adopting extrusion molding method. The effects of extrusion molding process conditions,cutting frequency,calcination temperatures and atmosphere on the bulk density and physicochemical properties of residue hydrodesulfurization catalyst carrier were investigated. The results showed that the bulk density and physicochemical properties of the carrier was the best under the preparation condition of acid/powder ratio(A +0. 5)mL·g-1,water/powder ratio(B+0. 10)mL·g-1,and kneading time(t+5)min. When cutting and shaping frequency was 40 Hz,the catalyst carrier with length distribution(3 -8)mm accounted for 87. 14%;with the increase of calcination temperature,the specific surface area,pore amount with pore size less than 6 nm and bulk density of the carrier decreased;with the decrease of calcination gas flow,the surface area and bulk density of the carrier decreased,pore volume increased,the pores with pore size distribution less than 6 nm and( 6 -20 ) nm were reduced and increased,respectively. By controlling exactly calcination temperature and calcination gas flow,the alumina support with suitable surface area,stabe bulk density, and concentrated pore size distribution concentration was prepared,which could meet the industrial requirements for the fixed bed residue hydrodesulfurization.%采用挤出成型法制备氧化铝载体，考察挤出成型工艺条件、切粒频率、焙烧温度和焙烧气氛对渣油加氢脱硫催化剂载体堆积密度及物化性能的影响。结果表明，酸粉比（A+0.5）mL·g-1、水粉比（B+0.10）mL·g-1和混捏时间（t+5）min制备的载体堆积密度合适，物化性能优良；切粒整形频率为40 Hz时，载体条长分布中，（3~8）mm条占87 .14%；随着焙烧温度的升高，载体比表面积减少，孔径分布中小于6 nm孔减少，堆积密度减小；随着焙烧气量的减少，载体比表面积降低，孔体积增加，堆积密度减小，孔径分布中小于6 nm孔减少，（6~20）nm孔增加。精确控制载体焙烧温度和气量，可制备出比表面积合适、堆积密度稳定、孔径分布集中和满足固定床渣油加氢脱硫要求的工业氧化铝载体。