球形SiO2模型催化剂的制备及在渣油扩散系数测定中的应用  

PREPARATION OF SiO_2 MODEL CATALYST AND ITS APPLICATION IN THE MEASUREMENT OF DIFFUSION COEFFICIENT OF PETROLEUM RESIDUE

作　　者：刘子媛[1,2] 陈胜利[1] 董鹏[1] 高金森[1] 葛秀军[1] 

机构地区：[1]中国石油大学重质油国家重点实验室,北京102249 [2]中国石油大学化学化工学院,山东青岛266555

出　　处：《石油学报（石油加工）》2009年第3期363-369,共7页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家重点基础研究发展规划“973”项目(2004CB217808);国家杰出青年科学基金项目(20725620)赞助

摘　　要：利用正硅酸乙酯水解缩合反应,制备了直径为23～293nm的单分散SiO2球形颗粒。通过SiO2颗粒的有序堆积,在800℃煅烧后,得到直径为4mm的球形模型催化剂和10～20目筛分(粒径0.85～1.68mm)的模型催化剂。建立了球形模型催化剂中的扩散数学模型,通过Laplace变换求得解析解。采用大港减压渣油超临界流体萃取7#(DG-7)抽提油和制备的SiO2模型催化剂进行扩散实验,得到DG-7抽提油在模型催化剂中的有效扩散系数的数量级在10-11～10-10m2/s范围,且有效扩散系数随模型催化剂的孔径增加而增大。当模型催化剂孔径由8nm增加到15nm时,有效扩散系数增加了1个数量级,说明DG-7抽提油在孔径小于8nm的模型催化剂孔道中的扩散受到孔径的限制。Spherical model catalyst with the diameter of 4 mm and 10--20 mesh（particle diameter of 0.85--1.68 ram） granular model catalyst were prepared by ordered packing of 23--293 nm monodisperse silica particles, which were prepared through hydrolysis and condensation of alkoxysilanes, and then calcining at 800℃. Based on the characteristics of the model catalyst and residue oil, the mathematical model of oil diffusing in the spherical model catalyst was established according to the material balance. Through Laplace transformation an analytical solution of the model was obtained. By using the prepared model catalysts, the diffusion coefficient of 7# fraction from Dagang （DG-7） residue by supercritical fluid extraction and fractionation was determined through the mathematic model. The diffusion coefficient increased as the pore size increased and the value ranges from 10^-11 to 10^-10 m^2/s. The diffusion coefficient was increased by about one order magnitude when the pore diameter increased from 8 nm to 15 nm, indicating that the diffusion of the oil fraction is hindered by the limited diffusion space when the pore size is less than 8 nm.

关 键 词：SIO2 模型催化剂 数学模型 渣油 扩散系数 

分 类 号：TQ426.7[化学工程]