水分子对初始碳烟颗粒形成过程影响的分子动力学模拟

doi:10.11949/j.issn.0438-1157.20180828

化工学报 ›› 2019, Vol. 70 ›› Issue (6): 2237-2243.DOI: 10.11949/j.issn.0438-1157.20180828

水分子对初始碳烟颗粒形成过程影响的分子动力学模拟

孟凯^1,²(),许建良^1,²,代正华^1,²(),刘海峰^1,²,王辅臣^1,²,龚剑洪³

1. 华东理工大学资源与环境工程学院，上海 200237
2. 上海市煤气化工程技术研究中心，上海 200237
3. 中国石油化工股份有限公司石油化工科学研究院，北京 100083

收稿日期:2018-07-23 修回日期:2019-03-13 出版日期:2019-06-05 发布日期:2019-06-05
通讯作者: 代正华
作者简介:<named-content content-type="corresp-name">孟凯</named-content>（1993—），男，硕士研究生，<email>616422294@qq.com</email>
基金资助:
国家自然科学基金项目(21776087);国家重点研发计划项目(2018YFB0605000，2017YFB0602600)

Molecular dynamics simulation of influence of water molecules on formation process of nascent soot particles

Kai MENG^1,²(),Jianliang XU^1,²,Zhenghua DAI^1,²(),Haifeng LIU^1,²,Fuchen WANG^1,²,Jianhong GONG³

1. College of Resources and Environment Engineering, East China University of Science and Technology, Shanghai 200237, China
2. Shanghai Engineering Research Center of Coal Gasification, Shanghai 200237, China
3. Sinopec Research Institute of Petroleum Processing, Beijing 100083, China

Received:2018-07-23 Revised:2019-03-13 Online:2019-06-05 Published:2019-06-05
Contact: Zhenghua DAI

摘要/Abstract

摘要：

采用LAMMPS软件，基于ReaxFF，以十氢化萘、萘、2-甲基蒽、1-乙基芘为催化油浆的模型化合物研究了600～2500 K温度下催化油浆形成初始碳烟颗粒的过程，考察了2500 K时水分子对初始碳烟颗粒形成过程的影响。研究表明温度在600 K时模型化合物分子主要是物理聚集成核。温度在900～1700 K时模型化合物分子处于聚集和分离的动态过程，无法从单体向碳烟颗粒转变。温度高于2100 K时主要是化学成核，模型化合物分子碳氢键先断裂，然后碳碳键断裂产生大量短碳链，碳链经成键和环化形成初始碳烟颗粒。温度在2500 K时水分子抑制模型化合物分子化学成核，随着体系氢碳比的增加，抑制初始碳烟颗粒形成的作用增强。水分子产生氢自由基和氢氧自由基，这些基团会直接导致模型化合物分子的侧链断裂和碳碳键断裂形成大量短碳链。碳链继续与氢自由基和氢氧自由基作用形成一氧化碳、二氧化碳、氢气、甲烷等而被消耗，水分子的作用为促进短碳链形成和抑制短碳链向形成初始碳烟颗粒的方向进行。

关键词: 催化油浆, 初始碳烟颗粒, 分子模拟, 热解, 成核

Abstract:

By using ReaxFF software, the process of forming the initial soot particles in the catalytic slurry at 600－2500 K was studied based on ReaxFF and the model compound of decalin, naphthalene, 2-methylindole and 1-ethylindole as catalytic oil slurry. The effect of water molecules on the formation of NSPs at 2500 K has been investigated. The study shows that the formation of the NSPs at 600 K is mainly due to the physical aggregation. At the temperature range of 1100－1700 K, model compound molecules are in a dynamic process of gathering and separating, and cannot transform from monomers to soot particles. At the temperature above 2100 K, the formation of NSPs is mainly due to the chemical nucleation. The carbon-hydrogen bonds of the model compound are broken firstly, then the carbon-carbon bonds are broken into a large number of short carbon chains, and the short carbon chains are bonded and cyclized to form the initial soot particles. At 2500 K, water molecules inhibit the chemical nucleation process of the model compound molecules, and the inhibition effect to the formation of the NSPs is enhanced with the increase of the hydrogen-to-carbon ratio. Water molecules produce hydrogen radicals and hydroxyl radicals, which directly lead to the formation of a large number of short carbon chains due to the cleavage of side-chains and carbon-carbon bonds. These carbon chains continue to be consumed by hydrogen radicals and hydroxyl radicals to form carbon monoxide, carbon dioxide, hydrogen, methane, etc. The water molecules can promote the formation of short carbon and inhibit the transition of short carbon chains toward the formation of NSPs.

Key words: fluid catalytic cracing slurry, nascent carbon particle, molecular simulation, pyrolysis, nucleation

中图分类号:

TK 16

孟凯, 许建良, 代正华, 刘海峰, 王辅臣, 龚剑洪. 水分子对初始碳烟颗粒形成过程影响的分子动力学模拟[J]. 化工学报, 2019, 70(6): 2237-2243.

Kai MENG, Jianliang XU, Zhenghua DAI, Haifeng LIU, Fuchen WANG, Jianhong GONG. Molecular dynamics simulation of influence of water molecules on formation process of nascent soot particles[J]. CIESC Journal, 2019, 70(6): 2237-2243.

图/表 7

图1 298 K时平衡状态的模型（粉色—碳原子；蓝色—氢原子）

Fig.1 Balanced model at 298 K

表1 我国几种催化油浆的性质

Table 1 Properties of some FCC slurry in China

项目	兰州石化FCC油浆	青岛炼化油浆	任丘FCC油浆
密度/(g/cm3)	0.9804	1.1198	1.0180
氢碳比H/C	1.23	0.91	1.17
饱和烃/%(质量)	30.97	5.94	30.60
芳香烃/%(质量)	54.38	87.37	57.00
胶质+沥青质/%(质量)	14.65	6.69	12.40

图2 模型在600 K温度时模拟的结束状态及初始和结束时的原子径向分布函数

Fig.2 Final state of model and atomic radial distribution function of initial state and final state at 600 K

图3 2 ns后不同温度对应的原子分布状态（粉色—碳原子；蓝色—氢原子）

Fig.3 Atomic distribution state at different temperatures after 2 ns

图4 不同温度和时刻时最大初始碳烟颗粒中所含碳原子的个数

Fig.4 Number of carbon atoms largest nascent soot particles at different time and temperature

图5 2500 K时不同氢碳比的模型中最大初始碳烟颗粒中的碳原子数

Fig.5 Number of carbon atoms in largest nascent soot particles of different hydrogen-carbon ratio systems at 2500 K

图6 水分子对初始碳烟颗粒形成的影响途径（灰色—碳原子；白色—氢原子；红色—氧原子）

Fig.6 Reaction pathways of water molecules on formation of initial soot particles

参考文献 25

1	张玮娜 . 重油加工处理技术浅析[J]. 化工管理, 2018, (17): 88-89.
	Zhang W N . A analysis of heavy oil processing technology[J]. Chemical Enterprise Management, 2018, (17): 88-89.
2	张东明 . 我国烯烃原料低碳化展望[J]. 化学工业, 2017, 35(5): 24-31.
	Zhang D M . Prospects of low carbonization of olefin raw materials in China[J]. Chemical Industry, 2017, 35(5): 24-31.
3	张乾, 李庆峰, 房倚天, 等 . 重油残渣焦水蒸气气化反应特性的研究[J]. 燃料化学学报, 2012, 40(9): 1074-1080.
	Zhang Q , Li Q F , Fang Y T , et al . Steam gasification reactivity of chars from heavy oil residue[J]. Journal of Fuel Chemistry and Technology, 2012, 40(9): 1074-1080.
4	Schuetz C A , Frenklach M . Nucleation of soot: molecular dynamics simulations of pyrene dimerization[J]. Proceedings of the Combustion Institute, 2002, 29(2): 2307-2314.
5	Chernov V , Thomson M J , Dworkin S B , et al . Soot formation with C1 and C2 fuels using an improved chemical mechanism for PAH growth[J]. Combustion and Flame, 2014, 161(2): 592-601.
6	Qiu L , Cheng X B , Li Z Q . Experimental and numerical investigation on soot volume fractions and number densities in non-smoking laminar n-heptane/n-butanol coflow flames[J]. Combustion and Flame, 2018, 191: 394-407.
7	Zhang T F , Thomson M J . A numerical study of the effects of n-propylbenzene addition to n-dodecane on soot formation in a laminar coflow diffusion flame[J]. Combustion and Flame, 2018, 190: 416-431.
8	Jerez A , Consalvi J L , Fuentes A . Soot production modeling in a laminar coflow ethylene diffusion flame at different oxygen indices using a PAH-based sectional model[J]. Fuel, 2018, 231: 404-416.
9	Li Q , Wang Q , Kayamori A . Experimental study and modeling of heavy tar steam reforming[J]. Fuel Processing Technology, 2018, 178: 180-188.
10	Ghiassi H , Toth P , Jaramillo I C , et al . Soot oxidation-induced fragmentation (Ⅰ): The relationship between soot nanostructure and oxidation-induced fragmentation(article)[J]. Combustion and Flame, 2016, 163: 179-187.
11	Li Y Y , Li G Y , Zhang H , et al . ReaxFF study on nitrogen-transfer mechanism in the oxidation process of lignite[J]. Fuel, 2017, 193: 331-342.
12	Liu J P , Liu P G , Wang M J . Molecular dynamics simulations of aluminum nanoparticles adsorbed by ethanol molecules using the ReaxFF reactive force field[J]. Computational Materials Science, 2018, 151: 95-105.
13	Jin H , Wu Y , Guo L J , et al . Molecular dynamic investigation on hydrogen production by polycyclic aromatic hydrocarbon gasification in supercritical water[J]. International Journal of Hydrogen Energy, 2016, 41(6): 3837-3843.
14	毛倩, 罗开红, van Duin A C T . 初始碳烟颗粒形成的反应分子动力学模拟[J]. 工程热物理学报, 2017, 38(5): 1087-1091.
	Mao Q , Luo K H , van Duin A C T . A ReaxFF molccular dynamics simulation of the formation of nascent soot particles[J]. Journal of Engineering Thermophysics, 2017, 38(5): 1087-1091.
15	韩嵩 . 航空煤油燃烧和碳烟形成初始反应的分子动力学模拟[D]. 北京: 中国科学院大学, 2018.
	Han S . Initial reaction pathway of aviation kerosene combustion and soot formation revealed by reactive molecular dynamics simulations[D]. Beijing: University of Chinese Academy of Sciences, 2018.
16	Han S , Li X X , Nie F G , et al . Revealing the initial chemistry of soot nanoparticle formation by Reaxff molecular dynamics simulations[J]. Energy & Fuels, 2017, 31(8): 8434-8444
17	杜林, 王五静, 张彼得, 等 . 基于ReaxFF场的矿物绝缘油热解分子动力学模拟[J]. 高压电技术, 2018, 44(2): 488-497.
	Du L , Wang W J , Zhang B D , et al . Molecular dynamics simulation of mineral insulating oil pyrolysis based on force field Reaxff[J]. High Voltage Engineering, 2018, 44(2): 488-497.
18	Liu J , Guo X . ReaxFF molecular dynamics simulation of pyrolysis and combustion of pyridine[J]. Fuel Processing Technology, 2017, 161: 107-115.
19	Sϕrensen M R , Voter A F . Temperature-accelerated dynamics for simulation of infrequent events[J]. Journal of Chemical Physics, 2000, 112(21): 9599-9606.
20	Chenoweth K , van Duin A C T , Goddard W A . ReaxFF reactive force for molecular dynamics simulations of hydrocarbon oxidation[J]. The Journal of Physical Chemistry A, 2008, 112(5): 1040-1053.
21	王遥 . FCC油浆的结构表征及提高其抗老化性能的改性反应研究[D]. 上海: 华东理工大学, 2018.
	Wang Y . Characterization of FCC slurry and study of modified reaction to increase aging resistance[D]. Shanghai: East China University of Science and Technology, 2018.
22	李斌 . 催化裂化油浆的综合利用[D]. 东营: 中国石油大学, 2011.
	Li B . Studies on the utilization of the FCC slurry[D]. Dongying: China University of Petroleum, 2011.
23	李林, 徐海清 . 催化油浆综合利用的技术措施[J]. 化学工业与工程技术, 2013, 34(1): 20-24.
	Li L , Xu H Q . Technical measures of comprehensive utilization of catalytic cracking slurry oil[J]. Journal of Chemical Industry & Engineering, 2013, 34(1): 20-24.
24	查庆芳, 张玉贞, 郭燕生, 等 . FCC油浆富芳烃分的热解[J]. 石油学报,2005,21(1): 49-56.
	Cha Q F , Zhang Y Z , Guo Y S , et al . Pyrolysis of aromatic enrichment fraction of FCC slurry[J]. Acta Petrolei Sinica, 2005, 21(1): 49-56.
25	Sato T , Trung P H , Tomita T , et al . Effect of water density and air pressure on partial oxidation of bitumen in supercritical water[J]. Fuel, 2012, 95(95): 347-351.

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水分子对初始碳烟颗粒形成过程影响的分子动力学模拟

Molecular dynamics simulation of influence of water molecules on formation process of nascent soot particles

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