Liao Yitao, Liu Tao, Du Xiaohui, Gao Xionghou
College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, China.
Lanzhou Petrochemical Research Center, Petrochemical Research Institute, PetroChina, Lanzhou, China.
Front Chem. 2021 Mar 8;9:640413. doi: 10.3389/fchem.2021.640413. eCollection 2021.
The effects of different iron contamination content on the formation of iron nodules and the performance of FCC catalysts have been studied by cyclic deactivation treatment using iron naphthenate. The catalysts were characterized by X-ray diffraction, N2 adsorption-desorption, and SEM. The catalysts' performance was evaluated by the Advanced Cracking Evaluation device. It has been found that there will be obvious nodulation on the catalyst when the iron concentration exceeds 7,400 μg/g. With the iron deposition from 53 μg/g to 11,690 μg/g, the crystal structure of zeolite will not be destroyed by iron. The surface area and pore volume of the catalyst decreased significantly; the surface area decreased from 125.3 m/g to 91.0 m/g, and the pore volume decreased from 0.21 cm/g to 0.16 cm/g. The studies also showed that the increase of iron deposition will lead to the decrease of catalytic reaction efficiency. With the iron deposition from 53 μg/g to 11,690 μg/g, the conversion decreased by 4.83%. Under the same 78 wt.% conversion, bottoms yield and coke yield increased by 2.15% and 1.31%, while gasoline yield and LCO yield decreased by 2.59% and 2.16%, respectively. The real state of the industrial iron contaminated equilibrium catalyst can be mimicked by using the cyclic deactivation method.
采用环烷酸铁进行循环失活处理，研究了不同铁污染含量对铁结节形成及催化裂化（FCC）催化剂性能的影响。通过X射线衍射、N2吸附-脱附和扫描电子显微镜对催化剂进行了表征。采用先进裂化评价装置对催化剂性能进行了评价。研究发现，当铁浓度超过7400μg/g时，催化剂上会出现明显的结瘤现象。随着铁沉积量从53μg/g增加到11690μg/g，铁不会破坏沸石的晶体结构。催化剂的比表面积和孔体积显著下降；比表面积从125.3m²/g降至91.0m²/g，孔体积从0.21cm³/g降至0.16cm³/g。研究还表明，铁沉积量的增加会导致催化反应效率降低。随着铁沉积量从53μg/g增加到11690μg/g，转化率下降了4.83%。在相同的78wt.%转化率下，渣油产率和焦炭产率分别增加了2.15%和1.31%，而汽油产率和轻循环油产率分别下降了2.59%和2.16%。采用循环失活方法可以模拟工业铁污染平衡催化剂的实际状态。
