研究了十二烷基硫酸钠对原位晶化制备小晶粒NaY的影响,并以包含小晶粒NaY的原位晶化产物为母体,通过铵交换和稀土离子交换制备出了REUSY催化剂.采用X射线衍射(XRD)、扫描电镜(SEM)、X射线荧光(XRF)及N2物理吸附-脱附等手段对样品进行了表征,采用微反活性评价装置和小型固定流化床(ACE)评价了所制备催化剂在重油催化裂化反应中的催化性能.结果表明:在原位晶化合成NaY的体系中,添加高岭土微球质量5%的十二烷基硫酸钠,可以将分子筛的平均晶粒尺寸由540 nm减小到250 nm.相比于常规的原位晶化型流化催化裂化(FCC)催化剂,以包含小晶粒NaY的原位晶化产物为母体所制备出的催化剂,在反应原料的转化率、裂化产物的选择性以及抗积碳性能等方面均有明显的提高或改善.
The in situ crystallization of small-grain NaY in the presence of lauryl sodium sulfate was investigated. The product containing small-grain NaY was used as a matrix to prepare REUSY catalyst via ammonium ion exchange and rare earth ion exchange. X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray fluorescence (XRF), and N2 physical adsorption-desorption were used to characterize the samples, while the catalytic performance of prepared catalysts was evaluated by micro-activity evaluation device and advanced catalytic evaluation (ACE). It is indicated that the addition of lauryl sodium sulfate (5% of Kaolin microsphere mass) to in situ crystallization system can decrease the average grain size of the zeolite from 540 to 250 nm. Relative to the conventional in situ crystallization fluid catalytic cracking (FCC) catalysts, the catalyst prepared from in situ crystallization product containing small-grain NaY exhibits improved performance in the conversion rate of feedstock, the selectivity of the cracking product, and the resistance to carbon deposition