磁性Mo/HZSM-5@SiO_(2)@Fe_(3)O_(4)催化剂可控制备及煤催化热解  

Controlled preparation and catalytic pyrolysis of coal over magnetic Mo/HZSM-5@SiO_(2)@Fe_(3)O_(4) catalyst

作　　者：张军兴 周安宁[1,2] 闫宁 陈福欣 贺新福[1,2] 杨志远 张亚婷[1,2] ZHANG Junxing;ZHOU Anning;YAN Ning;CHEN Fuxin;HE Xinfu;YANG Zhiyuan;ZHANG Yating(School of Chemistry and Chemical Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;Key Laboratory of Coal Resources Exploration and Comprehensive Utilization,MNR.,Xi’an 710021,China)

机构地区：[1]西安科技大学化学与化工学院,陕西西安710054 [2]自然资源部煤炭资源勘查与综合利用重点实验室,陕西西安710021

出　　处：《煤炭学报》2021年第6期1985-1994,共10页Journal of China Coal Society

基　　金：陕西省煤炭联合基金资助项目(2019JLP-10);陕西省重点产业创新链(群)-工业领域资助项目(2017ZDCXL-GY-10-01-02)。

摘　　要：低阶煤炭资源量丰富,催化热解是实现其清洁高效利用的重要途径。目前,低变质煤催化热解技术存在焦油产率低,重质组分高,催化剂回收难等发展瓶颈。为此,设计制备了磁性核壳型载体HZSM-5@SiO_(2)@Fe_(3)O_(4)(简写为HSF)和煤热解磁性Mo/HSF催化剂。研究了SiO_(2)隔热包覆层的层数,热处理温度和时间,以及包覆HZSM-5载体层对HSF磁性的影响。以补连塔煤为研究样品,探讨了磁性Mo/HSF催化剂的煤热解催化活性及磁选回收特性。研究结果表明,在常温条件下,随着SiO_(2)包覆层数不断增加,SiO_(2)@Fe_(3)O_(4)饱和磁化强度和磁选回收率均呈现不同程度的降低,当SiO_(2)包覆层数为2层时,饱和磁化强度和磁选回收率下降程度最小,但提高热处理温度或延长热处理时间,包覆HZSM-5载体层均使其磁选回收率降低。以2层SiO_(2)包覆的SiO_(2)@Fe_(3)O_(4)为磁核制备的5%Mo/HSF磁性催化剂催化性能最好。在5%Mo/HSF作用下,补连塔煤热解的焦油产率达到10.8%,焦油中苯类质量分数增加了2.31%,酚类几乎不变,脂肪烃质量分数增加了8.44%,稠环芳烃质量分数减少9.64%。活性组分Mo的引入不仅可以提高焦油的品质,而且也提高了煤气中甲烷和CO比例,煤气中甲烷体积分数达50%以上。Mo/HSF催化剂初次磁选回收率可达到90.3%。随着该催化剂磁选回收次数增加,催化剂活性和磁选回收率明显下降,主要是因为催化剂表面积炭和磁核被还原,磁性减弱所致。Low rank coal resources are abundant,and catalytic pyrolysis is an important way to realize clean and efficient utilization of low rank coal resources.At present,the low rank coal catalytic pyrolysis technology has some bottlenecks,such as low tar yield,high heavy components,and difficulty in recovering catalyst.Therefore,in this study,the magnetic core-shell carrier HZSM-5@SiO_(2)@Fe_(3)O_(4)(HSF)and the magnetic Mo/HSF catalyst for coal pyrolysis were designed and prepared.The influence of the layers number of SiO_(2) thermal insulation coating,heat treatment temperature and time,HZSM-5 carrier layer on HSF magnetism were studied.The catalytic activity and the recovery rate by the magnetic separation of Mo/HSF in coal pyrolysis were investigated by using Bulanta coal(BLCoal)as sample.The results show that under normal temperature conditions,with the increase of SiO2 coating layers,the SiO_(2)@Fe_(3)O_(4) saturation magnetization intensity and magnetic separation recovery are reduced to some different degrees.When the number of SiO_(2) coating layers is two,the saturation magnetization intensity and magnetic recovery rate decrease in the least degrees.The increase of heat treatment temperature or the extension of heat treatment time,and coating HZSM-5 carrier layer can result in the decrease of the recovery rate.The 5% Mo/HSF magnetic catalyst using two layers of SiO_(2)@Fe_(3)O_(4) as magnetic core has the best catalytic performance.Under the action of 5%Mo/HSF catalyst,the tar yield reaches 10.8%,the benzene content in the tar increases by 2.31%,phenolic content is almost unchanged,the aliphatic hydrocarbon content increases by 8.44%,the polycyclic aromatic hydrocarbon content decreases by 9.64%.The introduction of active component Mo can not only improve the tar quality,but also increase the ratio of methane to CO in the gas,the methane content in the gas reaches more than 50%.The recovery of Mo/HSF catalyst can reach 90.3% in the first magnetic separation.With the increase of recovery times of magnetic separ

关 键 词：催化热解 磁性催化剂 磁选回收率 焦油提质 低阶煤 

分 类 号：TQ530[化学工程—煤化学工程] TQ426