碱性氮化物喹啉对催化裂化产物氮分布的影响

摘要

采用小型固定流化床实验装置,以喹啉为模型化合物,在反应温度500~560 ℃范围内,考察了大庆VGO和喹啉的催化裂化反应,以及剂油比和催化剂酸量对氮化物催化转化和产物氮分布的影响规律.结果表明:大庆VGO催化裂化后,汽油和柴油中氮化物的类型较少且含量很低,喹啉的加入不利于大庆VGO的转化,汽油和柴油的氮含量增加;喹啉在催化裂化过程中主要发生烷基化反应和裂化反应,提高反应温度有利于苯胺继续裂化生成氨;增大剂油比可以削弱碱性氮化物的竞争吸附效应,有利于降低液体产品的氮含量;提高催化剂酸量可以促进喹啉的转化,使原料氮更多地转移到焦炭中.%The effects of the mass ratio of catalyst to oil and the total acid content of catalyst on the conversion and nitrogen distribution of Daqing VGO and its mixture with quinoline were investigated respectively at 500-560 ℃ in a fixed fluidized bed reactor.The results show that quinoline exhibits an adverse influence to the reactivity of Daqing VGO,resulting in more nitrogen in gasoline and diesel than the single VGO feed.Alkylation and cracking reactions are the main pathways of quinoline during catalytic cracking.Aniline,as the middle product,can further crack into ammonia with the increase of temperature.The competitive adsorption of basic compounds can be weakened by raising mass ratio of catalyst to oil,resulting in decrease of nitrogen content in liquid products.The conversion of quinoline is significantly enhanced as the catalyst total acid content increases and more nitrogen is concentrated in coke.