非碱性氮化物催化裂化转化规律及反应化学研究

摘要

The impact of non-basic nitrogen compounds represented by indole on FCC reaction and the contribution and conversion rule of these compounds during the process was studied in a fixed fluidized bed(FFB).The results showed that the addition of non-basic nitrogen compounds reduces the conversion of FCC process,and influences the product distribution.The higher the nitrogen content in feedstock,the greater the influence on the reactions.In the catalytic cracking reaction of indole,the nitrogen in the raw material oil was distributed in gasoline distillates,diesel distillates,coke and heavy oil fractions were 12.58％,54.15％ and 24.88％ respectively.In addition,4.46％ nitrogen was converted into ammonia,and the nitrogen in the heavy oil distillate was less than 5 ％.Indole is the most susceptible to alkylation during catalytic cracking.Due to hydrogen transfer reaction,the nitrogen-containing heteroatomic ring of indole molecule is saturated,and then converted further into aniline or ammonia through the ring-opening cracking reaction.Ammonia reacts with olefin to form aniline and further quinoline.The macromolecular nitrogen compounds are generated from small molecule nitrogen compounds by cyclization and condensation reactions.%采用小型固定流化床装置,考察以吲哚为代表的非碱性氮化物对催化裂化过程的影响,以及非碱性氮化物在催化裂化过程中的分布规律和反应化学.结果表明:非碱性氮化物的加入会导致反应转化率下降,并影响产物分布,且加入量越大,影响越大;吲哚经过催化裂化反应,原料油中54.15％的氮分布于柴油馏分中,24.88％的氮转化到焦炭中,12.5S％的氮分布于汽油馏分中,4.46％的氮转化为氨气,进入重油馏分中的氮不足5％;吲哚在催化裂化过程中最易发生烷基化反应,吲哚分子中氮环更易通过氢转移反应被饱和,进而发生开环裂化反应生成苯胺类氮化物和氨气;烯烃和氨气可通过环化缩合反应生成苯胺及喹啉类六元氮杂环化合物;小分子氮杂环化合物可发生烷基化、环化缩合反应生成大分子氮化物.