高孔容、窄分布的纳米γ-氧化铝作为一种新型催化剂载体，可以降低大分子的扩散阻力，有效缓解催化剂的结焦失活，改善催化效果。本论文系统研究了膜分散微反应器中纳米γ-氧化铝的制备规律；并利用同轴环管型微通道对γ-氧化铝颗粒进行成型，系统研究了微通道中γ-氧化铝微球的制备规律；最后进行了纳米γ-氧化铝的放大试验，并进行催化性能评价。本文以NaAlO2和Al2(SO4)3为原料，通过膜分散微反应器内的沉淀法制备得到高孔容的纤维状γ-氧化铝。由于膜分散微反应器内混合强度高，过饱和度均一，γ-氧化铝的孔径分布得到有效控制。本文研究了反应温度、终点pH、NaAlO2浓度、两相流量、洗涤试剂和焙烧温度对γ-氧化铝性质的影响，通过优化工艺参数，制备得到了比表面积为238.5–586.9 m2/g，孔容为1.05–2.16 mL/g，平均孔径为10.2–18.2 nm的纤维状γ-氧化铝，其孔径分布在3–50 nm之间，方差低至0.09。纤维的长度在20–30 nm，直径在3–4 nm。随后，本文以膜分散微反应器制得的高孔容γ-氧化铝的前驱体拟薄水铝石（PB）为原料，利用同轴环管型微通道制备得到高孔容、粒径均一的γ-氧化铝微球。将“温度-pH复合引发凝胶化”（即加入甲基纤维素MC和六亚甲基四胺HMTA来加速氢氧化铝溶胶的凝胶化）与微流体技术结合，用以保证微球的球形度和尺寸均一性。本文研究了铝溶胶浓度、制备铝溶胶的原料PB的性质、两相流量对γ-氧化铝微球的影响。研究发现，以PB3为原料制备铝溶胶、控制铝溶胶浓度为10 wt%、两相流比（连续相/分散相）为14–50，可制备出直径为750–380 μm、具有均一孔结构的γ-氧化铝微球，其对应的孔容为1.20 mL/g，压碎强度为8.19–16.67 N/mm2。最后，利用100 L规模平台进行了高孔容、窄分布纳米γ-氧化铝的放大试验，将终点pH控制在8–8.5，通过水洗制备得到了比表面积为357.8–383.0 m2/g，孔容为1.08–1.19 mL/g，平均孔径为10.3–12.0 nm的γ-氧化铝纳米纤维。其孔径分布在3–50 nm之间，方差为0.06–0.11。催化性能评价结果表明，高孔容γ-氧化铝具有更优的重油转化能力和低碳烯烃选择性，和对比剂相比，可将催化裂化转化率从84.76%升高至85.18%，增产乙烯2.73%，液化气3.93%，丙烯2.2%，异丁烯0.29%。

Nanometer γ-alumina with a large pore volume and narrow pore size distribution, which has been used as a novel catalyst support, can reduce the internal diffusion resistance of large molecules and alleviate the coking and deactivation of the catalyst, thus improving the catalytic performance. This paper systematically studied the preparation of nanometer γ-alumina in the membrane dispersion microreactor. Meanwhile, a co-axial microchannel was employed to shape up these γ-alumina particles, and the synthesis of γ-alumina microspheres in the microchannel was systematically studied in this paper. Finally, the scale-up experiments of preparing nanometer γ-alumina were carried out and the catalytic performance was evaluated.Fibrous γ-Al2O3 with a large pore volume was prepared by precipitation method in a membrane dispersion microreactor with NaAlO2 and Al2(SO4)3 as reactants. The pore size distribution was controlled due to the high mixing intensity and relatively homogeneous saturation in the membrane dispersion microreactor. The influences of the reaction temperature, pH, concentration of the NaAlO2 aqueous solution, the two phase-flow rates, the washing reagents and of the calcination temperature were investigated. By optimizing the process parameters, γ-Al2O3 nanofibers with specific surface area of 238.5–586.9 m2/g, pore volume of 1.05–2.16 mL/g, average pore diameter of 10.2–18.2 nm could be obtained. The pore size distribution was 3–50 nm with a minimum distribution variance of 0.09. The lengths of the nanofibers were 20–30 nm and the diameters were 3–4 nm, respectively. The precursors of large-pore-volume γ-alumina synthesized in the membrane dispersion microreactor were used as raw materials to prepare uniform γ-alumina microspheres with large pore volumes using a co-axial microchannel. In this process, the so-called "temperature/pH-induced gelation" method, in which methylcellulose (MC) and hexamethylenetetramine (HMTA) were added to accelerate gelation of aluminum hydroxide sol, was combined with microfluidics technology to ensure sphericity and dimensional homogeneity of the prepared microspheres. The influences of the sol concentration, the properties of pseudo-boehmite (PB) used to obtain the sol, and the two phase-flow rates were investigated. By controlling the sol concentration at 10 wt% and the continuous to dispersed phase flow ratio at 14–50, 750–380-μm-diameter γ-alumina microspheres with uniform pore structures were synthesized using an aluminum hydroxide sol obtained from PB3. The pore volume was 1.20 mL/g, and the crushing strengths were 8.19–16.67 N/mm2. Finally, 100 L scale platform was employed to carry out the scale-up experiments of preparing nanometer γ-alumina with a large pore volume and narrow pore size distribution. With the pH value controlled at 8–8.5 and washed with water, γ-Al2O3 nanofibers with specific surface area of 357.8–383.0 m2/g, pore volume of 1.08–1.19 mL/g and average pore diameter of 10.3–12.0 nm were synthesized. The pore size distribution was 3–50 nm with a variance of 0.06–0.11. The results of catalytic performance evaluation showed that large-pore-volume γ-alumina had better heavy oil conversion ability and light olefin selectivity. Compared with contrast material, the catalytic cracking conversion rate increased from 84.76% to 85.18% and the yield of ethylene, LPG, propylene and isobutylene increased by 2.73%, 3.93%, 2.2% and 0.29%, respectively.