摘要
研究了以NaAlO2和Al2(SO4)3为原料连续并流成胶制备拟薄水铝石的工艺,运用正交设计和方差分析方法考察了各因素对γ-Al2O3的堆密度和比表面积的影响显著性,并采用XRD、TEM、氮吸附脱附仪、汞孔计和热分析仪等对产品的晶相、形态、比表面积、孔分布及结晶度进行表征。结果表明,最优工艺参数为:NaAlO2溶液质量浓度100g/L,成胶pH值为8,反应温度85℃,中和停留时间30min,老化时间60min,搅拌速率200r/min,由此得到堆密度不大于0.32g/mL、比表面积不大于200m2/g、总孔体积不小于1.2mL/g的具有双孔分布的大孔体积低密度γ-Al2O3载体,其中孔径大于100nm孔的孔体积占总孔体积的50%以上。
Pseudo-boehmites were prepared with NaAlO2-Al2 （SO4）2 method using continuous concurrent gelation process. Multiple tests were designed with orthogonal method to investigate the influences of neutralization and aging conditions on the bulk density and surface area of the prepared samples,and the results were analyzed by variance analysis. Techniques such as XRD, TEM, nitrogen adsorption-desorption,DTG-DTA and mercury porosimetry were employed to characterize the crystal phase, modality, surface area, pore size distribution and crystallinity of these samples. The results showed that under the optimal preparation conditions of a NaA102 concentration of 100 g/L; a precipitation pH value of 8;a reaction temperature of 85 ℃ ; a residence time of 30 min; an aging time of 60 min and with stirring speed of 200 r/min, the prepared sample possessed the characteristics of having bulk density 40.32 g/mL, surface areas ≤200 m^2/g,pore volume ≥1.2 mL/g,and a bimodal pore size distribution,in which the percentage of pores with radius ≥100nm was more than 50%.
出处
《石油炼制与化工》
CAS
CSCD
北大核心
2007年第5期28-33,共6页
Petroleum Processing and Petrochemicals
关键词
拟薄水铝石
氧化铝
比表面积
孔分布
密度
pseudoboehmite
aluminium oxide
specific surface
pore distribution
density
