拟薄水铝石干燥温度对γ-Al_2O_3载体压碎强度的影响

INFLUENCE OF DRYING TEMPERATURE OF PSEUDO-BOEHMITE ON CRUSH STRENGTH OF γ-Al_2O_3 SUPPORT

压碎强度是加氢催化剂最重要的参数之一 ,加氢催化剂的压碎强度主要取决于载体。笔者主要研究了拟薄水铝石干燥温度对γ Al2 O3 载体压碎强度的影响 ,拟薄水铝石的干燥温度控制在 6 0～ 110℃。结果表明 ,当拟薄水铝石干燥温度为 6 0℃时 ,所制备的γ Al2 O3 载体的压碎强度较高 ,为 2 1.9N/mm ,而且有较高的均匀度 ,σ11X— 值为 11.6 % (用σ11X— 表示载体强度的均匀度 ,其值越低 ,表示强度越均匀 ) ;当拟薄水铝石干燥温度为 90℃时 ,虽然γ Al2 O3 载体的压碎强度仍为 2 0 .8N/mm ,但强度的均匀度明显下降 ,σ11X— 值为 2 4 .9% ;当拟薄水铝石干燥温度为110℃时 ,γ Al2 O3 载体的压碎强度和均匀度都有较大程度的降低 ,分别为 12 .4N/mm和 32 .2 %。拟薄水铝石干燥温度对γ Al2 O3 载体压碎强度的影响可能与拟薄水铝石生成过程中所形成的一部分以氢键方式与粒子表面结合的“额外水”有关。

Crush strength is one of the most important variables of hydrotreating catalyst, which depends mainly upon that of its support. The influence of drying temperature of pseudo-boehmite on crush strength of γ -Al_2O_3 support was studied. Pseudo-boehmite was dried at temperature ranged from 60 to 110 ℃. It was found that drying temperature of pseudo-boehmite played an important role on crush strength of γ -Al_2O_3 support. When pseudo-boehmite was dried at 60 ℃, crush strength of γ -Al_2O_3 support, prepared from dried pseudo-boehmite, was 21.9 N/mm. Furthermore, the consistence of crush strength σ_ 11 X - was 11.6% (σ_ 11 X - is used to express consistence of crush strength. Lower value ofσ_ 11 X -, better consistence of crush strength). When pseudo-boehmite was dried at 90 ℃, the crush strength of γ -Al_2O_3 support was 20.8 N/mm and σ_ 11 X - was 24.9%. When pseudo-boehmite was dried at 110 ℃, the crush strength of γ -Al_2O_3 support was 12.4 N/mm, much lower than that dried at 60 ℃. At the same time it showed much less consistent, σ_ 11 X - was 32.2%. Influence of drying temperature of pseudo-boehmite on crush strength of γ -Al_2O_3 support was possibly related to some 'extro-water' bonded to the surface of particles of pseudo-boehmite through hydrogen bond, which was formed during production of pseudo-boehmite.