碱土金属型捕钒剂对催化裂化催化剂抗钒污染的作用

Improvement of Anti-Vanadium Ability of FCC Catalyst by Adding Vanadium Trap

制备了3种氧化镁含量不同的碱土金属型捕钒剂,并与催化裂化催化剂混合后进行钒污染处理,经焙烧、水热老化后得到实验室模拟的老化剂。采用低温静态氮吸附容量法、XRD、XRF、DTA、Py-FTIR等手段对试样进行表征。在微型评价装置上评价老化剂的催化性能,考察捕钒剂的种类及掺混量、钒污染量对捕钒剂性能的影响。实验结果表明,3种捕钒剂中VT-A捕钒剂的抗钒中毒的效果最好;随捕钒剂VT-A掺混量的增加,重油转化率和汽油收率均先增加后降低,适宜的掺混量为12%(w)时重油转化率和汽油收率分别可达到73.7%和48.4%;对于Cat-2-10%VT-A老化剂,钒污染量为7 000μg/g时重油转化率和汽油收率仍可达到67.9%和46.6%。

Three alkaline earth metal based vanadium traps were prepared and mixed with catalytic cracking catalysts.The mixed catalysts were contaminated with vanadium and then deactivated catalysts were obtained by the calcination and steam aging of the contaminated catalysts and used in catalytic cracking in a fluid bed microreactor.The above samples were characterized by means of BET,XRD,XRF,DTA and Py-FTIR.The effects of the vanadium trap dosage and type,and vanadium contamination on the performances of the vanadium traps were investigated.The results showed that all the vanadium traps had good performances in trapping vanadium,especially that the performances of VT-A were the best.With increasing the vanadium trap dosage,both the feedstock conversion and the gasoline yield increased.However,if the vanadium trap dosage was above 12％（w）,both the feedstock conversion and the gasoline yield would decline.When the vanadium trap dosage was 12％（w）,the feedstock conversion and the gasoline yield were 73.7％ and 48.4％,respectively.Under the conditions of Cat-2-10％VT-A as the deactivated catalyst and the vanadium contamination 7 000 μg/g,the feedstock conversion and the gasoline yield reached 67.9％ and 46.6％,respectively.