非碱氮化合物吲哚催化裂化转化规律的研究

STUDY ON CONVERSION OF NON-BASIC NITROGEN COMPOUND INDOLE IN FCC

采用固定床微反活性实验装置,以甲苯、十六烷、四氢萘为溶剂,研究了非碱性含氮化合物吲哚的催化裂化转化规律。反应温度、催化剂与原料油的质量比、空速、原料氮含量都影响待生催化剂的氮含量和氮在产物中的分布。吲哚在催化裂化实验条件下较易发生裂化开环反应,生成苯胺类和氨。催化剂的酸性、烃类溶剂的供氢能力对吲哚裂化有显著影响,酸性中心的作用有利于吲哚转化为氨;溶剂供氢能力越强,氨氮产率越高。提出了吲哚催化裂化的可能转化途径:吲哚通过物理或化学作用吸附于催化剂表面,或在催化剂上脱氢缩合生焦;吲哚烷基化;吲哚需先加氢生成二氢吲哚,二氢吲哚快速裂化转化为苯胺和氨。

Indole catalytic cracking was performed on a fixed-bed microactivity test unit by using toluene,cetane,and tetralin as solvents.Reaction temperature,catalyst to oil ratio,weight hourly space velocity and nitrogen content of feedstock would affect the nitrogen content of spent catalyst and the nitrogen distribution in products.Indole was easy to crack into anilines and ammonia in catalytic cracking.Catalyst acidity and hydrogen donating abilities of hydrocarbon solvent showed marked effects on indole cracking.The action of acid sites was conducive to yield ammonia.With the increase of the hydrogen donating ability of hydrocarbon solvent,ammonia yield increased.The possible reaction pathway of indole catalytic cracking was proposed as: indole was adsorbed on catalyst surface by physical or chemical adsorption,then condensation occurred to form coke through dehydrogenation.Indole was converted into alkylindole.Indole must be hydrogenated into indoline,and then indoline would be cracked into aniline and ammonia quickly.