催化裂化过程中热裂化反应与二次反应的研究

利用连续式小型提升管催化裂化实验装置，研究了重油催化裂化过程中热裂化反应和二次反应的特点；考察了反应温度、剂油比和油气停留时间对热裂化和二次反应（氢转移和异构化反应）的影响；给出了不同反应条件下催化裂化过程中的过裂化点，考察了过裂化点前后热裂化反应在催化裂化过程中所占比例及氢转移和异构化反应的变化。结果表明，降低反应温度，缩短停留时间，增加剂油比可以抑制催化裂化过程中不利的热裂化反应，有利于氢转移和异构化反应的发生；在由反应温度、剂油比和停留时间引起的过裂化点前后，热裂化、氢转移和异构化反应表现出各自的变化特点。

Studies on thermal cracking and secondary reactions in FCC process

Thermal cracking and secondary reactions occurred in FCC process were studied by using a continuous pilot riser-type FCC unit. The effects of operating parameters(reaction temperature, catalyst to oil ratio, contact time)on thermal cracking and secondary cracking were also investigated. Moreover, the influence of overcracking operation on thermal cracking, hydrogen transfer and isomerization reactions was particularly discussed. The experimental results show that low reaction temperature, short contact time of oil and catalyst, and high catalyst to oil ratio may suppress the detrimental thermal cracking dramatically, and benefit to hydrogen transfer and the isomerization reactions. In the overcracking operation caused by high temperature, the thermal cracking may be enhanced, and hydrogen transfer and the isomerization reactions may be decreased remarkably, while the condensation reaction between olefin and aromatic hydrocarbons can be enhanced. In the overcracking operation caused by high catalyst to oil ratio, the thermal cracking may be restrained while the hydrogen transfer and the isomerization reaction in the secondary reactions can be promoted obviously. In the overcracking operation caused by long contact time, the thermal cracking reaction increases and the hydrogen transfer and the isomerization reaction appear the same tendency as thermal cracking reaction.