封装型Ni基催化剂制备及其原位提质煤热解焦油的性能  

Preparation of encapsulated Ni-based catalyst and its performancein-situ upgrading of coal pyrolysis tar

作　　者：贾鹏 王明义 王玉高[1] 王俊文[1] 王焦飞 JIA Peng;WANG Mingyi;WANG Yugao;WANG Junwen;WANG Jiaofei(College of Chemical Engineering and Technology,Taiyuan University of Technology,Taiyuan 030024,China;Huayang New Material Technology Group Co.,Ltd.,Yangquan 045000,China;State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering,Ningxia University,Yinchuan 750021,China)

机构地区：[1]太原理工大学化学工程与技术学院,山西太原030024 [2]华阳新材料科技集团有限公司,山西阳泉045000 [3]宁夏大学省部共建煤炭高效利用与绿色化工国家重点实验室,宁夏银川750021

出　　处：《洁净煤技术》2024年第4期179-186,共8页Clean Coal Technology

基　　金：山西省基础研究计划资助项目(20210302123087);省部共建煤炭高效利用与绿色化工国家重点实验室开放课题资助项目(2021-K67)。

摘　　要：为实现煤热解焦油原位轻质化,分别用原位封装法和浸渍法制备Ni基催化剂,并考察这两种催化剂对热解焦油原位催化提质的影响。与不加催化剂相比,Ni含量2%Ni/HZSM-5可使焦油中轻质组分产率由5.8%提至6.9%,而相同Ni含量的Ni@HZSM-5可使轻质焦油产率提至7.6%。进一步分析Ni/HZSM-5和Ni@HZSM-5催化剂对焦油各馏分产率的影响,结果表明,2种催化剂均使焦油中重质组分明显降低,沥青质产率分别由5.4%降至1.3%和2.0%,但相较Ni/HZSM-5,Ni@HZSM-5使焦油中轻油和酚油产率分别上升38.5%和25.5%,萘油产率也有所上升,说明封装法制备的Ni基催化剂可使焦油中轻质组分最大程度保留。因为在Ni/HZSM-5中焦油裂解和热解气中富氢组分活化均发生在Ni表面,在促进富氢气体活化的同时也造成焦油过度裂解。而Ni@HZSM-5中Ni主要分布于分子筛孔道内,其良好择形催化性可使富氢气体分子进入HZSM-5分子筛内部与Ni接触产生·H和·CH x等富氢自由基,而焦油中大分子无法进入HZSM-5孔道,其裂解仅发生在分子筛外表面酸性位点上,避免了金属Ni参与焦油裂解,从而定向调控焦油裂解碎片和富氢自由基数量,达到体系内氢碳平衡,有效避免焦油碎片过度裂解,提高轻质焦油产率。In order to realize the in-situ upgrading process of coal pyrolysis tar,Ni-based catalysts were prepared by in-situ encapsulation method and impregnation method respectively,and the effects of these two catalysts on the in-situ catalytic upgrading of pyrolysis tar were investigated.Compared with no catalyst,Ni/HZSM-5 with Ni content of 2%can increase the yield of light components in tar from 5.8%to 6.9%,while Ni@HZSM-5 with the same Ni content can increase the yield of light tar to 7.6%.The influence of Ni/HZSM-5 and Ni@HZSM-5 catalysts on the yield of each component of tar was further analyzed.The results shows that both catalysts significantly reduces the heavy components in tar,and the asphaltene yield decreases from 5.4%to 1.3%and 2.0%,respectively.However,compared with Ni/HZSM-5,Ni@HZSM-5 increases the yield of light oil and phenol oil by 38.5%and 25.5%,respectively,and naphthalene oil also increases to a certain extent,indicating that the Ni based catalyst prepared by encapsulation method can maximize the retention of light components in tar.This is because in Ni/HZSM-5,both tar cracking and activation of hydrogen-rich components in pyrolysis gas occur on the Ni surface,which promotes the activation of hydrogen-rich gas and also causes excessive tar cracking.The Ni in Ni@HZSM-5 is mainly distributed in the pore of molecular sieve.Its excellent shape selection catalytic performance enables hydrogen-rich gas molecules to enter into the HZSM-5 and contact with Ni,producing hydrogen-rich free radicals such as·H and·CH x,while large molecules in tar cannot enter into the pore of molecular sieve.The cracking can only occur on the acid site on the outer surface of HZSM-5,avoiding the participation of metal Ni in tar cracking,so as to regulate the amount of tar cracking fragments and hydrogen-rich free radicals,so as to achieve the balance of hydrogen and carbon in the system.As a result,the excessive cracking of tar fragments is effectively avoided and the yield of light tar is improved.

关 键 词：煤热解 焦油催化提质 封装型催化剂 HZSM-5分子筛 

分 类 号：TQ523[化学工程—煤化学工程]