煤炭转化2025，Vol.48Issue(3)：38-47,10.DOI:10.19726/j.cnki.ebcc.202503005
热解油悬浮床-固定床组合加氢工艺转化过程和产物分布研究
Study on conversion process and product distribution of pyrolytic tar using a combined slurry bed-fixed bed hydrotreatment
摘要
Abstract
To investigate the hydrotreatment process of pyrolysis oil from the Hami region,as well as the influencing factors and product distribution characteristics,a combined slurry bed-fixed bed hydrotreatment technology was employed to study the coal pyrolysis oil hydrotreatment.After the hydrocracking of the full fraction of pyrolysis oil in a slurry bed,the fractions below 370℃were fed into a fixed bed unit for secondary hydrotreatment,yielding naphtha and diesel fractions as the main liquid products.The fractions above 370℃underwent vacuum distillation to remove residue,and the resulting vacuum gas oil was recycled back into the slurry bed for further hydrotreatment.Analysis of the reaction process and intermediate products indicates that the slurry bed effectively converted heavy fractions in the coal pyrolysis oil.Heavy fractions(>350℃)account for over 50%of the coal pyroly-sis oil,with maltenes and asphaltene comprising 25.41%and 29.51%,respectively.These heavy fractions are difficult to convert directly using fixed bed hydrotreatment alone.In reaction conditions of 450℃and 17 MPa,slurry-bed pre-treatment results in complete conversion of asphaltenes.Distil-lation data shows that the yield of light oil(<370℃)reaches 89.51%,representing an increase of nearly 40%.Most heteroatoms such as sulfur,nitrogen,and oxygen are removed,with the mass frac-tion of nitrogen reduced from 0.88%to 0.11%,the mass fraction of sulfur from 0.09%to 0.03%,and the hydrogen-to-carbon ratio n(H)/n(C)increased from 1.28 to 1.44.The proportion of light oil(<350℃)increases from 42.15%to over 70%.After the pretreatment,the coal tar enters the fixed bed hydrotreatment unit.In reaction conditions of 350℃and 15 MPa,most heteroatoms in the light oil are removed,with sulfur and nitrogen contents reduced to below 5 mg/kg.The bromine index of the resulting naphtha and diesel fractions is 0,indicating a complete conversion of olefins and aromat-ics into saturated hydrocarbons.The final product comprised 36.90%naphtha and 48.71%diesel.The naphtha is suitable as a catalytic reforming feedstock with an aromatic potential exceeding 70%.The diesel fraction,with a cetane number of only 40,is unsuitable as a standalone diesel product but exhibited an extremely low freezing point,making it an ideal blending component for specialty diesel used in ultra-cold environments.The study demonstrates that the combined slurry bed and fixed bed process is suitable for handling pyrolysis oil feedstocks with high asphaltene and polar compound con-tent,significantly enhancing the conversion of heavy oil and improving both product yield and quality.关键词
热解油/悬浮床加氢/固定床加氢/石脑油/柴油Key words
pyrolytic tar/slurry bed hydrotreatment/fixed bed hydrotreatment/naphtha/diesel分类
化学化工引用本文复制引用
逯波,黄澎,单贤根,卢军,赵渊..热解油悬浮床-固定床组合加氢工艺转化过程和产物分布研究[J].煤炭转化,2025,48(3):38-47,10.基金项目
国家重点研发计划项目(2023YFB4103400). （2023YFB4103400）
