氯化镁中试热解炉热工过程数值计算研究

doi:10.19964/j.issn.1006-4990.2023-0166

Abstract

Abstract:

In order to explore the complex thermal process in the pyrolysis furnace，the core equipment of MgCl₂ spray pyrolysis process，and improve the quality of process products and equipment service life，Euler-Lagrange method was used to establish a mathematical model of gas-particle two-phase flow heat transfer coupled with pyrolysis reaction.The temperature field，particle decomposition process and HCl distribution during the stable operation of pyrolysis furnace were studied.And the influence of gas inlet temperature and flow rate on MgO conversion and HCl distribution was explored.The results showed that the product conversion rate was gradually increased with the increase of flue gas inlet temperature and inlet flow in the scope of the study.When the flue gas inlet was kept at 1.5 m³/s， the product conversion rate reaches 100% at the inlet temperature of 1 423 K. When the flue gas inlet temperature was kept at 1 273 K， the product conversion rate reaches 100% at the inlet flow rate of 2.25 m³/s.As the particles moving downward，the HCl concentration was radually increased and reached a maximum concentration of 6.5% at the discharge port.Moreover，with the increase of flue gas inlet temperature and inlet flow，the HCl concentration at the discharge port showed a change law of firstly increasing and then decreasing.The flue gas inlet temperature and inlet flow rate corresponding to the maximum value were 1 373 K and 1.75 m³/s，respectively.

Key words: MgCl₂, pyrolysis, Euler-Lagrange method, CFD, numerical simulation

CLC Number:

TQ132.2

WANG Jinji, ZHAO Liang, ZHANG Menghui, XU Hanlu, DONG Hui. Numerical simulation of thermal characteristics in magnesium chloride pilot pyrolysis furnace[J]. Inorganic Chemicals Industry, 2023, 55(12): 140-145.

Figures/Tables 12

Fig.1

Table 1

Kinetic parameters of MgCl2·6H2Othermal decomposition"

编号	方程式	指前因子 A_m/s^-1	活化能E/（kJ‧mol^-1）
1	$M g C l 2 ⋅ 6 H 2 O → M g C l 2 ⋅ 4 H 2 O + 2 H 2 O$	3.6×10⁹	66.8
2	$M g C l 2 ⋅ 4 H 2 O → M g C l 2 ⋅ 2 H 2 O + 2 H 2 O$	8.8×10¹⁷	138.0
3	$M g C l 2 ⋅ 2 H 2 O → M g C l 2 ⋅ H 2 O + H 2 O$	4.6×10⁹	77.2
4	$M g C l 2 ⋅ H 2 O → M g O H C l + H C l$	78.6	135.6
5	$M g O H C l → M g O + H C l$	1.2×10³	92.2

Table 1

Table 2

Table 3

Table 4

Fig.2

Fig.3

Fig.4

Fig.5

Fig.6

Fig.7

Fig.8

References 14

1	张苏江，张琳，姜爱玲，等. 中国盐湖资源开发利用现状与发展建议［J］. 无机盐工业， 2022， 54（10）：13-21.
	ZHANG Sujiang， ZHANG Lin， JIANG Ailing， et al. Current situation and development suggestions of development and utilization of salt lake resources in China［J］. Inorganic Chemicals Industry， 2022， 54（10）：13-21.
2	蒋晨啸，陈秉伦，张东钰，等. 我国盐湖锂资源分离提取进展［J］. 化工学报， 2022， 73（2）：481-503. doi: 10.11949/0438-1157.20211207
	JIANG Chenxiao， CHEN Binglun， ZHANG Dongyu， et al. Progress in isolating lithium resources from China salt lake brine［J］. CIESC Journal， 2022， 73（2）：481-503.
3	刘家辉，宁志强，谢宏伟，等. 氧化镁的制备方法及发展趋势综述［J］. 有色金属科学与工程， 2021， 12（3）：12-19.
	LIU Jiahui， NING Zhiqiang， XIE Hongwei， et al. Preparation methods and development trend of magnesium oxide［J］. Nonferrous Metals Science and Engineering， 2021， 12（3）：12-19.
4	王超超. 水氯镁石制备高纯氧化镁和碱式硫酸镁水泥研究［D］. 太原：山西大学， 2020.
	WANG Chaochao. Study on preparation of high purity magnesium oxide and basic magnesium sulfate cement with bischofite［D］. Taiyuan： Shanxi University， 2020.
5	刘源滔，刘富舟，杜玮，等. 水氯镁石喷雾热解制备氧化镁［J］. 材料科学与工程学报， 2018， 36（6）：1010-1015，903.
	LIU Yuantao， LIU Fuzhou， DU Wei， et al. Preparation of magnesium oxide from bischofite by spray pyrolysis［J］. Journal of Materials Science and Engineering， 2018， 36（6）：1010-1015，903.
6	都永生，孙庆国，火焱，等. 氯化镁喷雾热解制备氧化镁的研究［J］. 无机盐工业， 2013， 45（4）：13-14，25.
	DU Yongsheng， SUN Qingguo， HUO Yan， et al. Study on preparation of magnesium oxide by spray pyrolysis of magnesium chlori-de［J］. Inorganic Chemicals Industry， 2013， 45（4）：13-14，25.
7	DU Wei， SUN Ze， LU Guimin， et al. CFD aided design of integrated spray pyrolysis furnace for liquid ore exploitation［J］. Che-mical Engineering and Processing：Process Intensification， 2017，122：245-257.
8	KARIM M R， BHUIYAN A A， SARHAN A A R， et al. CFD simulation of biomass thermal conversion under air/oxy-fuel conditions in a reciprocating grate boiler［J］. Renewable Energy， 2020， 146：1416-1428. doi: 10.1016/j.renene.2019.07.068
9	DIBA M F， KARIM M R， NASER J. Numerical modelling of a bubbling fluidized bed combustion：A simplified approach［J］. Fuel， 2020， 277：118170. doi: 10.1016/j.fuel.2020.118170
10	SHAVER D， PODOWSKI M. Modeling of interfacial forces for bubbly flows in subcooled boiling conditions ［J］. Transactions of the American Nuclear Society， 2015， 113（10）：1368-1371.
11	MILLER R S， HARSTAD K， BELLAN J. Evaluation of equilibrium and non-equilibrium evaporation models for many-droplet gas-liquid flow simulations［J］. International Journal of Multiphase Flow， 1998， 24（6）：1025-1055. doi: 10.1016/S0301-9322(98)00028-7
12	SAZHIN S S. Advanced models of fuel droplet heating and evaporation［J］. Progress in Energy and Combustion Science， 2006， 32（2）：162-214. doi: 10.1016/j.pecs.2005.11.001
13	HUANG Qiongzhu， LU Guimin， WANG Jin， et al. Mechanism and kinetics of thermal decomposition of MgCl₂·6H₂O［J］. Metallurgical and Materials Transactions B， 2010， 41（5）：1059- 1066. doi: 10.1007/s11663-010-9390-4
14	祝杰，刘振华，杨云峰，等. 运用Rosin-Rammler函数研究喷淋塔内液滴粒径分布规律［J］. 高校化学工程学报， 2015， 29（5）：1059-1064.
	ZHU Jie， LIU Zhenhua， YANG Yunfeng， et al. Applying the rosin-rammler function to study on drop size distribution in spray to-wer［J］. Journal of Chemical Engineering of Chinese Universities， 2015， 29（5）：1059-1064.

边界	边界类型	DPM设置	热边界类型
烟气入口	Velocity inlet	Escape
烟气出口	Pressure outlet	Escape
排料口	Wall	Escape	绝热
其余炉壁	Wall	Reflect	绝热

入口温度/K	气体出口温度及误差			产品转化率/%
入口温度/K	实验值/K	模拟值/K	误差/%	实验值	模拟值	误差
1 223	890.83	906.96	-1.78	74.50	77.90	-4.36
1 273	897.50	937.54	-4.27	89.14	87.97	1.33
1 323	998.64	967.60	3.21	90.69	94.25	-3.78
1 373	1 020.10	1 002.12	1.79	99.38	97.58	1.84

[1]	REN Teng, LI Shengdong, WANG Dexi, CHU Fuzhou, SHAO Lixin. Numerical simulation analysis of influence of jet position on mixing effect of carbonization reactor [J]. Inorganic Chemicals Industry, 2023, 55(7): 109-114.
[2]	LU Dachuan, GU Weihua, ZHAO Jing, ZHUANG Xuning, DONG Bin, BAI Jianfeng. Research progress of influencing factors of pyrolysis of municipal sludge and residue recycling [J]. Inorganic Chemicals Industry, 2023, 55(5): 8-15.
[3]	ZHANG Sen,WAN Jun,CHEN Tianhu,DONG Shiwei,XU Liang,LI Yaqian,ZHAO Yueling. Research on heat treatment of NaCl-KCl waste salt in pesticide industry [J]. Inorganic Chemicals Industry, 2023, 55(2): 106-112.
[4]	ZHANG Xing,XU Jie,WANG Zibing,HOU Peng,HE Long,LIU Huan. Effect of feedstock particle size on kinetics of limestone thermal decomposition reaction [J]. Inorganic Chemicals Industry, 2023, 55(2): 79-84.
[5]	YANG Wenbo,WU Pan,HE Jian,LIU Changjun,JIANG Wei. Study on effect of heating rate on structure-activity of g-C₃N₄photocatalyst by pyrolysis of urea [J]. Inorganic Chemicals Industry, 2022, 54(4): 169-174.
[6]	SHEN Jiaqi,YAN Shenghu,ZHANG Yue,LIU Jianwu,SHEN Jiefa. Study on intensification of gas-liquid reaction process for sodium chloride waste salt to ammonium alkali [J]. Inorganic Chemicals Industry, 2022, 54(12): 99-105.
[7]	TIAN Yijuan,YAN Chaoqun,CHENG Zhiliang,QUAN Xuejun,LI Gang. Detoxification of Cr（Ⅵ） from chromite ore processing residue by pyrolysis with citrus peel [J]. Inorganic Chemicals Industry, 2021, 53(12): 129-134.
[8]	CHEN Xue,ZHANG Menghui,ZHAO Liang,DONG Hui,WANG Dexi. Study on pyrolysis process of Mg（NO₃）₂·nH₂O [J]. Inorganic Chemicals Industry, 2021, 53(12): 91-94.
[9]	Zhang Yan,Zhao Zhenzhong,Ma Zhaohui,Zhao Yancai,Chen Zhiyu,Ma Zhengqiang. Optimization of process for preparation of battery grade lithium carbonate by carbonization [J]. Inorganic Chemicals Industry, 2020, 52(3): 68-71.
[10]	Zhu Guihua,He Weize,Tang Haoting,Yi Shanzhen,Chen Yong. Simulation and improvement of flow field in side-entry wind salt mud drying room [J]. Inorganic Chemicals Industry, 2020, 52(12): 80-85.
[11]	Feng Junli,Yang Junfan,Wu Jingwu,Li Xu,Zhang Qingjian. Determination of mercury in crude zinc oxide by DMA-80 mercury analyzer [J]. Inorganic Chemicals Industry, 2019, 51(8): 73-75.
[12]	DU Yong-Sheng, SUN Qing-Guo, HUO Yan, HAN Ji-Long, LI Ming-Zhen. Study on preparation of magnesium oxide by spray pyrolysis of magnesium chloride [J]. INORGANICCHEMICALSINDUSTRY, 2013, 45(4): 13-.
[13]	YU He-Hua. Research on influencing factors of preparation of silicon tetrafluoride gas by pyrolysis from sodium fluosilicate [J]. INORGANICCHEMICALSINDUSTRY, 2013, 45(4): 46-.
[14]	ZHANG Xiao-Gang, ZHANG Jin, TANG Ying, LIU Dai-Jun, LI Bin, RONG Chou. Experiment research on pyrolysis of witherite in production of barium hydroxide [J]. INORGANICCHEMICALSINDUSTRY, 2012, 44(7): 19-.
[15]	LI Jing-Guan, ZHANG Lin-Jin, CHEN Chuan-Hui, YE Xu-Chu. Numerical simulation of oxygen volume fraction in chromite roasting process [J]. INORGANICCHEMICALSINDUSTRY, 2012, 44(2): 33-.

National Inorganic Salts Information Center

Inorganic Acid-Base-Salt Committee of CIESC

Numerical simulation of thermal characteristics in magnesium chloride pilot pyrolysis furnace

RichHTML

PDF (PC)

Knowledge

Abstract

Cite this article

share this article

Figures/Tables 12

References 14

Related Articles 15

Metrics

Comments

Recommended 0