CIESC Journal ›› 2019, Vol. 70 ›› Issue (8): 2898-2908.DOI: 10.11949/j.issn.0438-1157.20181375

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Effect of steam atmosphere on cracking behavior and carbon deposition of coal tar model compounds

Jianrong ZHAI1(),Mei ZHONG1,2(),Fengyun MA1,Haoquan HU2   

  1. 1. Key Laboratory of Coal Clean Conversion & Chemical Engineering Process of Xinjiang Uygur Autonomous Region, College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046, Xinjiang, China
    2. State Key Laboratory of Fine Chemicals, Institute of Coal Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, Liaoning, China
  • Received:2018-11-19 Revised:2018-12-14 Online:2019-08-05 Published:2019-08-05
  • Contact: Mei ZHONG

水蒸气对煤焦油模化物裂解行为及析碳的影响

翟建荣1(),钟梅1,2(),马凤云1,胡浩权2   

  1. 1. 新疆大学化学化工学院,新疆维吾尔自治区煤炭清洁转化与化工过程重点实验室,新疆 乌鲁木齐 830046
    2. 大连理工大学化工学院,煤化工研究所,精细化工国家重点实验室,辽宁 大连 116024
  • 通讯作者: 钟梅
  • 作者简介:翟建荣(1996—),男,硕士研究生,838903286@qq.com
  • 基金资助:
    国家自然科学基金项目(21606187);新疆维吾尔自治区政府联合基金重点项目(U1703252);高等学校学科创新引智计划(111计划)项目(D18022)

Abstract:

The Ni-Ce/Al2O3 catalyst was synthesized via mechanochemical method. The effects of steam on the cracking behavior of toluene and pyrene as coal tar model compounds were investigated in a fixed bed reactor. Based on the product distribution, the cracking mechanism of the conversion of pyrene to naphthalene was proposed and verified by D2O as a tracer. The types and structural characteristics of carbon deposition on the spent catalysts were characterized by XRD, TG-DTG and Raman, etc. The results showed that the addition of steam obviously enhanced the cracking rate of pyrene, compared with the pure nitrogen atmosphere, and it increased first and then decreased with the increase of steam-carbon ratio (S/C) and reaching a maximum of 98.93% at S/C=0.15, increased by 32.09% in comparison with S/C=0. A downward trend was that the yield of carbon decomposition decreased from 10.04% to 5.39% with the increase of S/C ratio from 0 to 0.26. In addition, carbon analysis results show that the main type of carbon deposits were β-type and γ-type at S/C=0. On the contrary, in the presence of steam, the activity of higher α-type carbon content increased. Therefore, it indicated that the carbon elimination by steam inhibited the conversion of Cα to Cβ and Cγ.

Key words: catalyst, catalysis, fixed-bed, model compound, steam-carbon ratio, carbon type

摘要:

采用机械化学法制备Ni-Ce/Al2O3催化剂,在固定床反应器中考察了水蒸气气氛对煤焦油模型化合物甲苯+芘催化裂解行为的影响。根据产物生成规律提出了芘向萘转化的裂解机理,并以D2O对其进行了验证。通过XRD、TG-DTG和Raman等表征了析碳的类型与结构特征。结果表明:相较于纯氮气气氛,水的加入可明显提升重质组分芘的裂解率,且随水碳比(S/C)增加呈先增加后降低的趋势,在S/C=0.15时达到最大值98.93%,比S/C=0时增加32.09%。析碳率随S/C比增加一直呈下降趋势,由S/C=0时的10.04%降至S/C=0.26时的5.39%。析碳分析结果表明,S/C=0时,生成的积炭类型主要是β型碳及γ型碳,水蒸气存在时,活性较高的α型碳含量增加,说明水蒸气的持续消碳作用抑制了Cα向Cβ与Cγ方向转化。

关键词: 催化剂, 催化(作用), 固定床, 模型化合物, S/C比, 析碳类型

CLC Number: