摘要
利用煤液化沥青制备高端炭材料是目前煤直接液化技术领域研究的热点,该过程实现的关键在于煤液化沥青的高效深度脱灰。以焦化洗油和神华煤液化沥青在热萃取釜中制备的热萃取液为研究对象,借助旋转黏度仪考察了1∶1,4∶1,6∶1三种剂渣比(焦化洗油与神华煤液化沥青的质量比)体系黏度随温度(20℃,40℃,60℃,80℃,100℃)的变化规律,探究了影响煤液化沥青灰分脱除和上层离心液收率的离心转速(1000 r/min,1500 r/min,2000 r/min,2500 r/min,3000 r/min,3500 r/min,4000 r/min)、剂渣比(1∶1,2∶1,3∶1,4∶1,5∶1,6∶1)和离心时间(5 min,10 min,15 min,20 min,25 min)三大行为因素,解析了神华煤液化沥青中灰分在焦化洗油混合体系中的粒度分布和形貌特征。结果表明:焦化洗油和神华煤液化沥青混合体系呈现出明显的高黏温正比特性,升高温度可显著减小不同剂渣比体系之间的黏度差异,焦化洗油和神华煤液化沥青萃取体系离心脱灰最佳工作参数为剂渣比4∶1、离心转速3000 r/min、离心时间15 min,此条件下灰分可降至0.06%,上层离心液收率可达75%。离心分离后灰分分布均匀,微观形貌呈现出不规则的锯齿层状堆叠特征,在焦化洗油和神华煤液化沥青混合体系中呈纳米级粒径分布是其不能深度脱除的根源,因此,可开发新型液相重力涡流、静电分离、沉降助剂法等技术并与离心技术相耦合,以期满足下游高端炭材料制备技术的指标要求,为煤炭直接液化技术规模化的发展和产业链的延伸提供技术支持。
The production of high-value carbon materials from direct coal liquefaction pitch is currently a focal point of research,with efficient and thorough deashing processes being identified as the key technology to achieve this goal.Thermal extraction liquids were prepared in an autoclave by washing oil and direct liquefaction pitch from Shenhua coal.The viscosity changes of three mixtures,with the solvent-to-residue ratios of 1∶1,4∶1,6∶1,were investigated at temperatures of 20℃,40℃,60℃,80℃,and 100℃using a rotational viscometer.Three factors affecting the ash removal from direct coal liquefaction pitch and the yield of upper centri-fugate were explored,including centrifugal speeds of 1000 r/min,1500 r/min,2000 r/min,2500 r/min,3000 r/min,3500 r/min,4000 r/min,solvent-to-residue ratios of 1∶1,2∶1,3∶1,4∶1,5∶1,6∶1,and centrifugal time of 5 min,10 min,15 min,20 min,25 min.The particle size distribution and morphology characteristics of ash in pitch from direct coal liquefaction in the washing oil were analyzed.The results indicate that the mixture system of wash oil and pitch from direct coal liquefaction exhibits a significant high viscosity temperature proportional characteristic.The viscosity difference among different solvent-to-residue ratios decreases with the increasing temperature.The optimal process parameters for the ash removal in the mixture system of wash oil and pitch from direct coal liquefaction are a solvent-to-residue ratio of 4∶1,centrifugal speed of 3000 r/min,and centrifugal time of 15 min,leading to a decreased ash content of 0.06%and a solvent yield of 75%.After centrifugal separation,the ash in the pitch displays a uniform distribution with characteristics of irregular zigzag morphology.The presence of nanoscale ash in the mixture system of wash oil and pitch from direct coal liquefaction is the reason for incomplete removal.New technologies such as liquid phase gravity eddy current,electrostatic separation,and sedimentation assistant methods should be developed and coupled with the centrifugal technology to meet the specific requirements of downstream preparation technology for high-value carbon materials,thereby providing technical support for large-scale development and the industrial chain extension.
作者
赵鹏
黄澎
刘敏
ZHAO Peng;HUANG Peng;LIU Min(China Coal Research Institute,100013 Beijing,China;National Energy Technology and Equipment Laboratory of Coal Utilization and Emission Control,100013 Beijing,China;Beijing Key Laboratory of Coal Based Carbon Material,100013 Beijing,China)
出处
《煤炭转化》
CAS
CSCD
北大核心
2024年第2期22-29,共8页
Coal Conversion
基金
国家重点研发计划项目(2022YFB4101604)
天地科技股份有限公司科技创新创业专项项目(2023-2-TD-ZD019)。
关键词
煤液化沥青
焦化洗油
离心
脱灰
行为因素
direct coal liquefaction pitch
wash oil from coke oven
centrifugation
deashing
behavior factors
作者简介
第一作者:赵鹏,研究员,E-mail:411296849@qq.com。
