氢气预处理降低钒对渣油接触裂化反应影响的初步研究

Study on hydrogen pretreatment to reduce effect of vanadium on residue contact cracking reaction

在固定流化床试验装置上开展了氢气预处理钒含量不同的接触剂对渣油接触裂化反应性能的影响研究。研究结果表明,污染接触剂上钒含量的增加促进了新晶相的生成,导致接触剂的结构发生变化,当钒质量分数达4.59%时,接触剂孔结构变化明显而且有明显莫来石相生成。与空白剂相比,钒污染促进渣油接触裂化反应过程中干气和焦炭的生成,导致生氢因子的增加。氢气预处理可以降低渣油接触裂化反应干气和焦炭的产率,提高液体收率,降低钒污染接触剂的脱氢活性和热裂化指数,当钒质量分数为3.54%时,较氢气预处理前,液体收率增加13百分点,生氢因子从5.48降到3.69,热裂化指数从39.73降到32.19。

The effects of different vanadium content of contact catalyst on residue contact cracking performance were carried out on a fixed fluidized bed reactor with hydrogen pretreatment.The results showed that the increase of vanadium content on the polluted contact catalyst promoted the formation of new crystal phases,which leaded to changes in the structure of the contact catalyst.When the content of vanadium reached 4.59%,the pore structure of the contact catalyst changed significantly,and there was obvious formation of mullite phase.Vanadium pollution promoted the production of dry gas and coke in the residue contact cracking reaction,leading to an increase of hydrogen generation factor.Hydrogen pretreatment could reduce the yield of dry gas and coke in the residue contact cracking reaction,increase the liquid yield,and reduce the dehydrogenation activity and thermal cracking index of the vanadium polluted contact catalyst.When the content of vanadium was 3.54%,compared with that before hydrogen pretreatment,the liquid yield increased by 13 percentage points,the hydrogen generation factor decreased from 5.48 to 3.69,and the thermal cracking index decreased from 39.73 to 32.19.