摘要
以中/低温煤焦油重组分(CTAR)为原料进行悬浮床加氢实验,采用1 H-NMR、XRD、IR、元素分析及相对分子质量测定手段对生焦前驱体(HI)进行分析,并以显微镜观测、SEM、IR等方法对焦炭的官能团、堆积结构及表面形态进行了研究,推测CTAR加氢过程的生焦机理。结果表明,CTAR悬浮床加氢效果理想,HI中芳环稠度低,侧链少而短,平均相对分子质量低,分子间缔合性小,没有芳香片层堆积结构,不易裂化产生大分子自由基,是轻质生焦前驱体。焦炭为1μm左右的球状颗粒吸附于炭质颗粒而形成的10μm左右的聚合体。CTAR中分布的甲苯不溶物及硫化的催化剂颗粒在反应中提供的"2个结焦中心(催化剂和微晶粒子),1个吸附中心(炭质颗粒)"使焦粒变小、壁相焦减少。
The slurry-bed hydrocracking experiment of medium/low temperature coal tar heavy（350℃）fraction（CTAR）was carried out in magnetic-stirred autoclave,and the properties of coke precursor（heptane insoluble,HI）were analyzed with the help of 1 H-NMR,XRD,IR ultimate analysis and average relative molecular mass determination（VPO）.In addition,the functional groups,stacking structure and microstructure of coke were characterized by means of microscope,SEM,IR to speculate the coke formation mechanisms of CTAR in slurry-bed hydrocracking.The results showed that hydrogenation effect of CTAR slurry-bed hydrocracking was good.HI was a kind of lighter coke precursor with low aromatic ring consistency,few and short aliphatic chains,small average relative molecular mass and no aromatic sheet stacking structures,which was not easy to break to generate polycyclic aromatics radicals in the hydrocracking.Coke was the aggregate（about10μm）formed by globular particles（about 1μm）adsorbing on the surface of carbonaceous particles.The smaller coke particles and less amount of coke on the surface of reactor were observed in CTAR hydrocracking,because the toluene insoluble（TI）and sulfurized catalyst provided ＂two coke centers（catalyst and micro grain）and one adsorption center（carbonaceous particles）＂for reaction system.
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
2015年第5期1089-1096,共8页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
中国石油大学(华东)创新工程项目(YCX2014024)
中央高校基本科研业务费专项资金项目(14CX05032A)资助
关键词
煤焦油重组分
悬浮床加氢
生焦前驱体
生焦机理
吸附中心
载焦体
coal tar heavy fraction
slurry-bed hydrocracking
coke precursor
coke formation mechanism
adsorption center
coke trap
