甲醇气氛下低阶煤热解气中CO加氢制芳烃机理研究

王月伦; 安会会; 张雪纯; 马云欣; 詹贵贵; 刘豪杰; 曹景沛

doi:10.19906/j.cnki.JFCT.2022065

甲醇气氛下低阶煤热解气中CO加氢制芳烃机理研究

doi: 10.19906/j.cnki.JFCT.2022065

王月伦^{1, 2, ,},
安会会¹,
张雪纯¹,
马云欣¹,
詹贵贵³,
刘豪杰¹,
曹景沛^{1, 2, ,}

1.
中国矿业大学煤炭加工与高效洁净利用教育部重点实验室, 江苏徐州 221116
2.
中国矿业大学江苏省碳资源精细化利用工程研究中心, 江苏徐州 221116
3.
徐州市建设工程检测中心有限公司, 江苏徐州 221116

基金项目: 国家自然科学基金（21975282）资助

详细信息

通讯作者:
E-mail: wangyuelun@126.com

caojingpei@cumt.edu.cn

中图分类号: TQ530.2
计量
- 文章访问数: 2949
- HTML全文浏览量: 48
- PDF下载量: 33
- 被引次数: 0
出版历程
- 收稿日期: 2022-04-28
- 修回日期: 2022-06-02
- 录用日期: 2022-07-11
- 网络出版日期: 2022-08-03
- 刊出日期: 2022-12-28

Mechanism of hydrogenation of CO to aromatics from coal pyrolysis gas of low rank under methanol atmosphere

1.
Key Laboratory of Coal Processing and Efficient Utilization, Ministry of Education, China University of Mining and Technology, Xuzhou 221116, China
2.
Jiangsu Province Engineering Research Center of Fine Utilization of Carbon Resources, China University of Mining and Technology, Xuzhou 221116, China
3.
Xuzhou Construction Engineering Testing Center Co., Ltd, Xuzhou 221116, China

Funds: The project was supported by National Natural Science Foundation of China (21975282)

摘要

摘要: 由于低阶煤含氧官能团较多，热解过程产生大量CO和CO₂，甲醇气氛提供的活性氢可实现CO或CO₂催化加氢生成轻质芳烃。本研究采用密度泛函理论探讨了甲醇气氛下低阶煤热解气之一CO于Fe/HZSM-5催化剂上经烯烃中间体制芳烃的机理，结果表明，CO于Fe₅C₂(510)表面加氢生成低碳烯烃，进而通过多次甲基化和去质子化实现C−C键偶联及链增长，其中，甲基化需活化能较高。 ${\rm{C}}^+_{6} $ 芳构化过程通过氢转移、去质子化及环化生成苯，其氢转移最难。整个CO加氢制芳烃过程以甲基化所需能垒最高，成为该反应的决速步。
- CO加氢 /
- 芳烃 /
- 密度泛函理论 /
- 反应机理
Abstract: Because there were much more oxygen-containing functional groups for low-rank coal, a large amount of CO and CO₂ were produced during the pyrolysis process. Catalytic hydrogenation of CO or CO₂ to light aromatics could be realized by supplying active hydrogen from methanol. Density functional theory (DFT) was used to investigate the mechanism of CO hydrogenation to aromatics via olefins intermediates over Fe/HZSM-5 catalyst under methanol atmosphere. The results showed that light olefins were formed by CO hydrogenation on Fe₅C₂ (510) surface. C−C bond coupling and chain propagation were achieved through multiple processes such as methylation and deprotonation. Methylation required a high activation energy among these processes. The aromatization of ${\rm{C}}^+_6 $ to benzene was carried out by reactions of hydrogen transfer, deprotonation and cyclization. Hydrogen transfer was the most difficult to happen. In the whole process of CO hydrogenation to aromatics, the energy barrier of methylation was the highest, which was the rate-determining step.
- CO hydrogenation /
- aromatics /
- density functional theory /
- reaction mechanism

HTML全文

FIG. 2027. FIG. 2027.

下载: 全尺寸图片幻灯片

图 1 46T团簇模型示意图

Figure 1 Schematic diagram of 46T cluster model

(a): Main view, (b): Back view

下载: 全尺寸图片幻灯片

图 2 Fe₅C₂ (510)模型示意图

Figure 2 Schematic diagram of Fe₅C₂ (510) model

下载: 全尺寸图片幻灯片

图 3 CO和H吸附构型图

Figure 3 CO and H adsorption configuration diagram

下载: 全尺寸图片幻灯片

图 4 生成中间体C₂H₄过程中的过渡态

紫色：Fe，红色：O，白色：H，绿色：表面物种的C，灰色：Fe₅C₂(510)表面C

Figure 4 Transition states in the formation of C₂H₄

Purple: Fe; red: O; white: H; green: C of surface species; gray: surface C of Fe₅C₂(510)

下载: 全尺寸图片幻灯片

图 5 生成C₂H₄势能图

Figure 5 Potential energies of the formation of C₂H₄

下载: 全尺寸图片幻灯片

图 6 生成 ${\rm{C}}^+_6 $ 路径示意图

Figure 6 Path of the formation of ${\rm{C}}^+_6 $

下载: 全尺寸图片幻灯片

图 7 生成C ${}^+_6 $ 路径势能图

Figure 7 Potential energies of the formation of C ${}^+_6 $

下载: 全尺寸图片幻灯片

图 8 C ${}^+_6 $ 芳构化路径示意图

Figure 8 Process of aromatization for C ${}^+_6 $

下载: 全尺寸图片幻灯片

图 9 C ${}^+_6 $ 芳构化势能图

Figure 9 Potential energies of C ${}^+_6 $ aromatization

下载: 全尺寸图片幻灯片

图 10 甲醇脱水过程过渡态

Figure 10 Transition state of methanol dehydration process

下载: 全尺寸图片幻灯片

图 11 C ${}^+_6 $ 芳构化氢转移过渡态

Figure 11 Transition states of hydrogen transfer for C ${}^+_6 $ aromatization

下载: 全尺寸图片幻灯片

表 1 生成C₂H₄计算结果

Table 1 Calculation results of forming C₂H₄ (823 K,101 kPa)

Reaction	∆H/(kJ·mol⁻¹)	∆G^≠/(kJ·mol⁻¹)	k/s⁻¹
H + CO→H + C + O	76	124	2.31 × 10⁵
H + C + O→CH + O	−50	12	2.81 × 10¹²
CH + O + H→CH₂ + O	75	82	1.03 × 10⁸
CH₂ + CH₂→CH₂CH₂	10	112	1.38 × 10⁶

下载: 导出CSV

表 2 生成C ${}^+_6 $ 计算结果

Table 2 Calculation results of forming C ${}^+_6 $ (823 K,101 kPa)

Reaction	∆H/(kJ·mol⁻¹)	∆G^≠/(kJ·mol⁻¹)	k/s⁻¹
M1	30	135	4.37 × 10⁴
D1	−42	53	7.25 × 10⁹
M2	34	158	1.50 × 10³
D2	−41	79	1.64 × 10⁸
M3	51	96	1.35 × 10⁷
D3	−22	61	2.31 × 10⁹
M4	39	165	6.16 × 10²

下载: 导出CSV

表 3 C ${}^+_6 $ 芳构化计算结果

Table 3 Calculation results of C ${}^+_6 $ aromatization (823 K,101 kPa)

Reaction	∆H/(kJ·mol⁻¹)	∆G^≠/(kJ·mol⁻¹)	k/s⁻¹
D1	−18	57	4.13 × 10⁹
H1	60	122	3.10 × 10⁵
C1	−109	78	1.92 × 10⁸
D2	−55	48	1.54 × 10¹⁰
H2	−29	107	2.77 × 10⁶
D3	−11	31	1.85 × 10¹¹
H3	−27	94	1.85 × 10⁷
D4	−81	15	1.91 × 10¹²

下载: 导出CSV

参考文献(26)

[1]	赵君强. 煤化工绿色发展研究[J]. 煤炭与化工,2020,43(7):126−127. doi: 10.19286/j.cnki.cci.2020.07.036 ZHAO Jun-qiang. Research on green development of coal chemical industry[J]. Coal Chem Ind,2020,43(7):126−127. doi: 10.19286/j.cnki.cci.2020.07.036
[2]	林涛海. 中国煤化工工业发展现况及发展趋向[J]. 化工管理,2021,(19):63−64. doi: 10.19900/j.cnki.ISSN1008-4800.2021.19.028 LIN Tao-hai. The present situation and future development trend of coal chemical industry in China[J]. Chem Enterpr Manage,2021,(19):63−64. doi: 10.19900/j.cnki.ISSN1008-4800.2021.19.028
[3]	YAN L J, LIU Y J, LV P, WANG M J, LI F, BAO W R. Effect of Brønsted acid of Y zeolite on light arene formation during catalytic upgrading of coal pyrolysis gaseous tar[J]. J Energy Inst,2020,93(6):2247−2254. doi: 10.1016/j.joei.2020.06.007
[4]	REN X Y, FENG X B, CAO J P, TANG W, WANG Z H, YANG Z, ZHAO J P, ZHANG L Y, WANG Y J, ZHAO X Y. Catalytic conversion of coal and biomass volatiles: A review[J]. Energy Fuels,2020,34(9):10307−10363. doi: 10.1021/acs.energyfuels.0c01432
[5]	HE L, HUI H L, LI S G, LIN W G. Production of light aromatic hydrocarbons by catalytic cracking of coal pyrolysis vapors over natural iron ores[J]. Fuel,2018,216:227−232.
[6]	LIU Y J, YAN L J, BAI Y H, LI F. Catalytic upgrading of volatile from coal pyrolysis over faujasite zeolites[J]. J Anal Appl Pyrolysis,2018,132:184−189. doi: 10.1016/j.jaap.2018.03.001
[7]	LI Y, AMIN M N, LU X M, LI C S, REN F Q, ZHANG S J. Pyrolysis and catalytic upgrading of low-rank coal using a NiO/MgO-Al₂O₃ catalyst[J]. Chem Eng Sci,2016,155:194−200. doi: 10.1016/j.ces.2016.08.003
[8]	KONG X J, BAI Y H, YAN L J, LI F. Catalytic upgrading of coal gaseous tar over Y-type zeolites[J]. Fuel,2016,180:205−210.
[9]	HE L, LI S G, LIN W G. Catalytic cracking of pyrolytic vapors of low-rank coal over limonite ore[J]. Energy Fuels,2016,30:6984−6990.
[10]	JIN L J, BAI X Y, LI Y, DONG C , HU H Q, LI X. In-situ catalytic upgrading of coal pyrolysis tar on carbon-based catalyst in a fixed-bed reactor[J]. Fuel Process Technol,2016,147:41−46.
[11]	XU Y B, YUAN X, CHEN M Y, DONG A L, LIU B, JIANG F, YANG S J, LIU X H. Identification of atomically dispersed Fe-oxo species as new active sites in HZSM-5 for efficient non-oxidative methane dehydroaromatization[J]. J Catal,2021,396:224−241. doi: 10.1016/j.jcat.2021.02.028
[12]	CHAREONPANICH M, BOONFUENG T, LIMTRAKUL J. Production of aromatic hydrocarbons from Mae-Moh lignite[J]. Fuel Process Technol,2002,79(2):171−179. doi: 10.1016/S0378-3820(02)00111-X
[13]	张海永,王永刚,张培忠,林雄超,朱豫飞. NiW/Al₂O₃-Y催化剂的制备及其对煤焦油加氢处理的研究[J]. 燃料化学学报,2013,41(9):1085−1091. doi: 10.1016/S1872-5813(13)60046-8 ZHANG Hai-yong, WANG Yong-gang, ZHANG Pei-zhong, LIN Xiong-chao, ZHU Yu-fei. Preparation of NiW catalysts with alumina and zeolite Y for hydroprocessing of coal tar[J]. J Fuel Chem Technol,2013,41(9):1085−1091. doi: 10.1016/S1872-5813(13)60046-8
[14]	GU Z L, CHANG N, HOU X P, WANG J P, LIU Z K. Experimental study on the coal tar hydrocracking process in supercritical solvents[J]. Fuel,2012,91(1):33−39. doi: 10.1016/j.fuel.2011.07.032
[15]	靳立军, 李扬, 胡浩权. 甲烷活化与煤热解耦合过程提高焦油产率研究进展[J]. 化工学报,2017,68(10):3669−3677. doi: 10.11949/j.issn.0438-1157.20170465 JIN Li-jun, LI Yang, HU Hao-quan. Research progress of integrated methane activation with coal pyrolysis for improving coal tar yield[J]. CIESC J,2017,68(10):3669−3677. doi: 10.11949/j.issn.0438-1157.20170465
[16]	WANG Y L, YU J P, AN H H, JIN W J, QIAO J Q, SUN Y, CAO J P. Catalytic upgrading of coal tar coupling with methanol using model compound over hierarchal ZSM-5 for increasing light aromatic production under atmosphere pressure[J]. Fuel Process Technol,2021,211:106600. doi: 10.1016/j.fuproc.2020.106600
[17]	ZHANG M, MOUTSOGLOU A. Catalytic fast pyrolysis of prairie cordgrass lignin and quantification of products by pyrolysis-gas chromatography-mass spectrometry[J]. Energy Fuels,2014,28(2):1066−1073. doi: 10.1021/ef401795z
[18]	LI L, FAN H J, HU H Q. A theoretical study on bond dissociation enthalpies of coal based model compounds[J]. Fuel,2015,153:70−77. doi: 10.1016/j.fuel.2015.02.088
[19]	FU Y, NI Y M, CHEN Z Y, ZHU W L, LIU Z M. Achieving high conversion of syngas to aromatics[J]. J Eng Chem,2022,66:597−602.
[20]	XU Y F, WANG J, MA G Y, BAI J Y, DU Y X, DING M Y. Direct synthesis of aromatics from syngas over Mo-modified Fe/HZSM-5 bifunctional catalyst[J]. Appl Catal A: Gen,2020,598:117589.
[21]	FUJIMOTO K, KUDO Y, TOMINAGA H O, Synthesis gas conversion utilizing mixed catalyst composed of CO reducing catalyst and solid acid:II. Direct synthesis of aromatic hydrocarbons from synthesis gas[J]. J Catal,1984,87(1):136−143. doi: 10.1016/0021-9517(84)90176-3
[22]	XU Y, LIU D, LIU X. Conversion of syngas toward aromatics over hybrid Fe-based Fischer-Tropsch catalysts and HZSM-5 zeolites[J]. Appl Catal A: Gen,2018,552:168−183. doi: 10.1016/j.apcata.2018.01.012
[23]	CHENG K, ZHOU W, KANG J C, HE S, SHI S l, ZHANG Q H, PAN Y, WEN W, WANG Y. Bifunctional catalysts for one-step conversion of syngas into aromatics with excellent selectivity and stability[J]. Chem,2017,3:334−347. doi: 10.1016/j.chempr.2017.05.007
[24]	ZHANG M H, REN J, YU Y Z. Insights into the hydrogen coverage effect and the mechanism of Fischer-Tropsch to olefins process on Fe₅C₂(510)[J]. ACS Catal,2020,10:689−701. doi: 10.1021/acscatal.9b03639
[25]	ZHAO H B, JIANG H, CHENG M, LIN Q, LV Y J, XU Y, XIE J Z, LIU J X, MEN Z W, MA D. Boron adsorption and its effect on stability and CO activation of χ-Fe₅C₂ catalyst: An ab initio DFT study[J]. Appl Catal A: Gen,2021,627:118382. doi: 10.1016/j.apcata.2021.118382
[26]	WANG S, CHEN Y Y, WEI Z H, QIN Z F, MA H, DONG M, LI J F, FAN W B, WANG J G. Polymethylbenzene or alkene cycle? theoretical study on their contribution to the process of methanol to olefins over H-ZSM-5 zeolite[J]. J Phys Chem C,2015,119(51):28482−28498. doi: 10.1021/acs.jpcc.5b10299