CO氧化偶联反应器模拟与优化

doi:10.11949/0438-1157.20220761

摘要/Abstract

摘要：

CO与亚硝酸甲酯(MN)氧化偶联制草酸二甲酯(DMO)是合成气制乙二醇过程的关键步骤，现有工业装置存在效率低的问题。采用包括副反应(生成碳酸二甲酯和甲酸甲酯)动力学的动力学模型和二维两相反应器模型，对CO氧化偶联的移热式固定床反应器进行建模，研究了换热方式及操作条件对反应器性能和安全性的影响。结果表明，以温度的二阶导数作为飞温的判据是灵敏和可靠的。与常规的逆流和恒温移热方式相比，并流移热使反应器形成更为均匀的温度分布，有利于提高反应器产能。增加入口MN含量会升高反应器MN转化率和热点温度；但是，由于CO、NO和反应物MN之间存在竞争吸附，增加入口CO和NO含量会导致MN转化率和热点温度降低，所以增加入口压力导致MN转化率降低。且热点温度对MN和NO的含量更为敏感，应严格控制入口MN和NO的含量。采用遗传算法进行反应器工况寻优，确定了最优的反应条件，可提高单台反应器对应的乙二醇(EG)年产能至12万吨。

关键词: 草酸二甲酯, 氧化偶联, 固定床反应器, 优化, 数学模拟

Abstract:

The oxidative coupling of CO and methyl nitrite (MN) to produce dimethyl oxalate (DMO) is a key step in the process of synthesis gas to ethylene glycol, and the existing industrial equipment has the problem of low efficiency. A two-dimensional heterogeneous reactor model with a kinetic model including side reactions of dimethyl carbonate and methyl formate was established to simulate and optimize the tubular fixed-bed reactor, with focus on the influences of coolant-flow schemes and operation conditions. The results showed that ∂²T/∂z² at hot spot reflected the potential of thermal runaway sensitively and reliably. The evenness of the temperature distribution indicated co-current coolant-flow was preferred to be employed to achieve a higher conversion, compared with the conventional isothermal and counter-current schemes. Moreover, it was found that MN accelerated reactions, while CO and NO inhibited the reactions by adsorption competition with MN, and the elevated total pressure moderated the reaction and hot spot temperature. Compared with the influence of CO, the hot spot temperature was more sensitive to the contents of MN and NO, which should be strictly controlled. The genetic algorithm was used to optimize the process conditions of the reactor, and found that the annual production capacity of EG by one reactor unit could reach 120000 t.

Key words: dimethyl oxalate, oxidative coupling reaction, fixed-bed reactor, optimization, mathematical modeling

中图分类号:

TQ 203.2

迟子怡, 刘成伟, 张欲凌, 李学刚, 肖文德. CO氧化偶联反应器模拟与优化[J]. 化工学报, 2022, 73(11): 4974-4986.

Ziyi CHI, Chengwei LIU, Yuling ZHANG, Xuegang LI, Wende XIAO. Reactor simulation and optimization for CO oxidative coupling to dimethyl oxalate reactions[J]. CIESC Journal, 2022, 73(11): 4974-4986.

图/表 15

图1 DMO合成工业反应器的结构简图

Fig.1 Structure sketch of DMO synthesis industrial reactor

表1 模型参数

Table 1 Parameters in two-dimensional heterogeneous model

参数	表达式
D_er^[16]	$D e r = u f d p 8.65 1 + 19.4 d p D t$
k_er^[20]	k_er= k_er,0+ k_fRePr / Pe_r
k_fs^[16,21]	k_fsd_p/ D_ij = 2+1.1Sc^1/3Re^0.6
h_fs^[21]	h_fsd_p/ k_f = 2+1.1Pr^1/3Re^0.6
h_w^[20]	h_w= Nu_wk_f/d_p， $N u w = N u w, 0 + 1 / 1 N u w * + 1 N u m$ ， $N u w *$ = 0.3Pr^1/3Re^0.75, Nu_m= 0.054PrRe
h_o^[22]	$h o = λ 0 J H o P r o 1 / 3 φ o ε h 2 / D e$ $J H o = 0.378 R e o 0.554 Z - 15 / 10 + 0.41 R e o 0.5634 25 - Z / 10$
h_ew^[15]	对于并流和逆流： $1 h e w = 1 h w + δ λ w + 1 h o + R d$ 对于恒温换热： $1 h e w = 1 h w + δ λ w + R d$

表1 模型参数

Table 1 Parameters in two-dimensional heterogeneous model

参数	表达式
D_er^[16]	$D e r = u f d p 8.65 1 + 19.4 d p D t$
k_er^[20]	k_er= k_er,0+ k_fRePr / Pe_r
k_fs^[16,21]	k_fsd_p/ D_ij = 2+1.1Sc^1/3Re^0.6
h_fs^[21]	h_fsd_p/ k_f = 2+1.1Pr^1/3Re^0.6
h_w^[20]	h_w= Nu_wk_f/d_p， $N u w = N u w, 0 + 1 / 1 N u w * + 1 N u m$ ， $N u w *$ = 0.3Pr^1/3Re^0.75, Nu_m= 0.054PrRe
h_o^[22]	$h o = λ 0 J H o P r o 1 / 3 φ o ε h 2 / D e$ $J H o = 0.378 R e o 0.554 Z - 15 / 10 + 0.41 R e o 0.5634 25 - Z / 10$
h_ew^[15]	对于并流和逆流： $1 h e w = 1 h w + δ λ w + 1 h o + R d$ 对于恒温换热： $1 h e w = 1 h w + δ λ w + R d$

表2 动力学参数

Table 2 Kinetic parameters

A_k	A_k,ref	B_k/(kJ/mol)
K_CO·	0.13	-103.23
K_NO·	0.32	-92.91
$K C H 3 C O O ·$	3.22	-31.25
K_H·	1.01	-60.90
k_DMO	2.19	-62.12
k_DMC	0.42	-5.54
k_MF	0.24	49.13

表2 动力学参数

Table 2 Kinetic parameters

A_k	A_k,ref	B_k/(kJ/mol)
K_CO·	0.13	-103.23
K_NO·	0.32	-92.91
$K C H 3 C O O ·$	3.22	-31.25
K_H·	1.01	-60.90
k_DMO	2.19	-62.12
k_DMC	0.42	-5.54
k_MF	0.24	49.13

图2 冷却水流量和流动方向对反应器性能的影响

Fig.2 Effect of coolant flow and direction on reactor performance

图3 入口温度对反应器性能的影响

Fig.3 Effect of inlet temperature on reactor performance

表3 压力对反应器性能影响

Table 3 Effect of pressure on reactor performance

P_in/kPa	X_MN/%	S_DMO/%	S_DMC/%	S_MF/%	T_max/^oC	ΔP/kPa	STY/(kg/h)
450	90.20	95.70	3.41	0.88	158.04	159.74	2.92
500	85.64	96.43	2.95	0.62	152.60	137.08	2.79
550	80.43	96.93	2.62	0.45	148.23	120.79	2.64
600	75.08	97.28	2.37	0.35	145.11	108.30	2.47
650	69.90	97.54	2.17	0.28	143.00	98.34	2.31

图4 反应物浓度对反应器性能的影响

Fig.4 Effect of species content on reactor performance

表4 空速对反应器性能影响

Table 4 Effect of GHSV on reactor performance

GHSV/h^-1	X_MN/%	S_DMO/%	S_DMC/%	S_MF/%	T_max/^oC	ΔP/kPa	STY/(kg/h)
3000	69.90	97.54	2.17	0.28	143.00	98.34	2.31
3500	65.86	97.44	2.26	0.30	145.16	133.92	2.53
4000	62.61	97.29	2.38	0.34	147.62	177.03	2.75
4500	60.18	97.08	2.53	0.39	150.13	229.80	2.97
5000	58.65	96.77	2.75	0.48	152.82	296.35	3.20

图5 空速对反应器轴线温度的影响(入口压力650 kPa，绝压)

Fig.5 Effect of GHSV on axial temperature profile

图6 入口温度对反应器轴线温度及其二阶导的影响

Fig.6 Effect of gas inlet temperature on axial temperature and its second-order partial derivative

图7 入口压力对反应器轴线温度及其二阶导的影响

Fig.7 Effect of inlet pressure on axial temperature and its second-order partial derivative

图8 反应物浓度对反应器轴线温度及其二阶导的影响

Fig.8 Effect of feed contents on axial temperature and its second-order partial derivative

表5 优化条件

Table 5 Optimized conditions

No.	y_MN,in/%	y_CO,in/%	y_NO,in/%	T_in/℃	P_in/kPa	GHSV/h^-1	w_c/ (kg/s)	η	ε_b
1	12.57	40.00	7.94	130.55	535.32	3179.78	0.011	0.35	0.45
2	13.94	39.98	7.60	136.24	590.47	3744.12	0.013	0.25	0.50
3	13.79	40.00	5.29	137.32	505.30	4554.93	0.014	0.21	0.55
4	12.61	30.00	8.46	128.23	582.70	3375.64	0.013	0.38	0.45
5	12.63	30.00	5.70	126.36	578.14	3907.57	0.014	0.35	0.50
6	14.52	29.98	8.66	129.62	586.35	4999.46	0.020	0.36	0.55

表6 优化结果

Table 6 Optimized results

No.	X_MN/%	S_DMO/%	S_DMC/%	S_MF/%	T_max/^oC	ΔP/kPa	STY/(kg/h)
1	76.84	97.28	2.19	0.53	157.71	149.40	2.91
2	76.42	96.16	2.97	0.87	167.25	116.31	3.73
3	77.87	95.16	3.54	1.30	170.09	133.94	4.53
4	75.18	96.83	2.63	0.54	154.33	149.92	3.01
5	74.97	96.94	2.55	0.51	154.50	124.45	3.49
6	70.41	95.98	3.31	0.71	159.04	130.72	4.77

图9 优化条件下反应器性能

Fig.9 Reactor performance under optimized conditions

参考文献 31

1	Yue H R, Zhao Y J, Ma X B, et al. Ethylene glycol: properties, synthesis, and applications[J]. Chemical Society Reviews, 2012, 41(11): 4218-4244.
2	丁怡婷. 煤炭业结构更优底色更绿[N]. 人民日报, 2022-05-11.
	Ding Y T. Better structure and environmental protection of coal industry[N]. People's Daily, 2022-05-11.
3	张鑫. 2021年中国煤制乙二醇行业市场现状分析, 行业迎来增速迅猛阶段[EB/OL]. [2022-10-17]. .
	Zhang X. Analysis of the market status of China's coal-to-ethylene glycol industry in 2021, the industry will usher in a stage of rapid growth[EB/OL]. [2022-10-17]. .
4	Wei R X, Yan C L, Yang A, et al. Improved process design and optimization of 200 kt/a ethylene glycol production using coal-based syngas[J]. Chemical Engineering Research and Design, 2018, 132: 551-563.
5	刘秀芳, 计扬, 李伟, 等. 蛋壳型Pd/α-Al₂O₃催化剂的制备及活性[J]. 催化学报, 2009, 30(3): 213-217.
	Liu X F, Ji Y, Li W, et al. Preparation and catalytic activity of egg-shelled catalyst Pd/α-Al₂O₃ [J]. Chinese Journal of Catalysis, 2009, 30(3): 213-217.
6	Zhuo G L, Jiang X Z. Catalytic decompostiton of methyl nitrite over supported palladium catalysts in vapor phase[J]. Reaction Kinetics and Catalysis Letters, 2002, 77: 219-226.
7	Li Z H, Wang W H, Yin D X, et al. Effect of alkyl nitrite decomposition on catalytic performance of CO coupling reaction over supported palladium catalyst[J]. Frontiers of Chemical Science and Engineering, 2012, 6(4): 410-414.
8	Zhai H Y, Wang S M, Chen D K, et al. Research on thermal risk and decomposition behavior of methyl nitrite[J]. Chinese Journal of Chemical Engineering, 2020, 28(8): 2131-2136.
9	梁旭, 苗杰, 赵立红, 等. 一氧化碳偶联合成草酸二甲酯催化剂中试研究[J].天然气化工(C1化学与化工), 2018, 43(6): 80-83.
	Liang X, Miao J, Zhao L H, et al. Pilot test of the catalysts for synthesis of dimethyl oxalate by carbon monoxide coupling[J]. Natural Gas Chemical Industry, 2018, 43(6): 80-83.
10	李绍芬. 反应工程[M]. 3版. 北京: 化学工业出版社, 2013.
	Li S F. Reaction Engineering[M]. 3rd ed. Beijing: Chemical Industry Press, 2013.
11	Borio D O, Bucalá V, Orejas J A, et al. Cocurrently-cooled fixed-bed reactors: a simple approach to optimal cooling design[J]. AIChE Journal, 1989, 35(11): 1899-1902.
12	徐艳, 马新宾, 许根慧. 草酸二乙酯合成反应器参数敏感性研究[J]. 石油化工, 2003, 32: 835-837.
	Xu Y, Ma X B, Xu G H. Study on parameter sensitivity of diethyl oxalate synthesis reactor[J]. Petrochemical Technology, 2003, 32: 835-837.
13	徐艳, 马新宾, 李振花. 壳式固定床草酸二乙酯合成反应器模拟分析[J]. 化学反应工程与工艺, 2008, 24(3): 204-210.
	Xu Y, Ma X B, Li Z H. Simulation analysis on tube-shell type fixed bed reactor for synthesis of diethyl oxalate in gaseous phase[J]. Chemical Reaction Engineering and Technology, 2008, 24(3): 204-210.
14	鲁文质. SDMO路线合成乙二醇的模拟研究[D]. 上海: 上海交通大学, 2006.
	Lu W Z. Simulation on ethylene glycol synthesis by super DMO-based technology[D]. Shanghai: Shanghai Jiao Tong University, 2006.
15	毛文发, 郑赛男, 骆念军, 等. 列管固定床反应器内CO氧化偶联制草酸二甲酯反应模拟及优化[J]. 化工学报, 2022, 73(1): 284-293.
	Mao W F, Zheng S N, Luo N J, et al. Simulation and optimization on oxidative coupling reaction of CO to dimethyl oxalate in a tubular fixed bed reactor[J]. CIESC Journal, 2022, 73(1): 284-293.
16	Iordanidi A. Mathematical modeling of catalytic fixed bed reactors[D]. Enschede: University of Twente, 2002.
17	Chi Z Y, Yang L Q, Li X G, et al. CO oxidative coupling with nitrite to oxalate over palladium catalyst: a comprehensive kinetic modeling[J]. Chemical Engineering Journal, 2022, 446: 136656.
18	唐先智. α-氧化铝载体的研制及其在CO偶联反应中的应用[D]. 上海: 上海交通大学, 2016.
	Tang X Z. Preparation of α-Al₂O₃ support and the application in CO coupling reaction[D]. Shanghai: Shanghai Jiao Tong University, 2016.
19	黄雄杰, 李学刚, 肖文德. CO偶联制备草酸二甲酯的动力学研究[J]. 天然气化工(C1化学与化工), 2019, 44(5): 37-40, 75.
	Huang X J, Li X G, Xiao W D. Kinetic study of CO coupling reaction to produce dimethyl oxalate[J]. Natural Gas Chemical Industry, 2019, 44(5): 37-40, 75.
20	Zenner A, Fiaty K, Bellière-Baca V, et al. Effective heat transfers in packed bed: experimental and model investigation[J]. Chemical Engineering Science, 2019, 201: 424-436.
21	Wakao N, Kaguei S. Heat and Mass Transfer in Packed Beds[M]. New York: Gordon & Breach Science, 1982.
22	高白薇. 管壳式换热器的计算与选型[J]. 安徽化工, 2017, 43(4): 83-85, 87.
	Gao B W. Calculation and selection of shell and tube heat exchanger[J]. Anhui Chemical Industry, 2017, 43(4): 83-85, 87.
23	陈敏恒, 丛德滋, 方图南, 等. 化工原理[M]. 3版. 北京: 化学工业出版社, 2006.
	Chen M H, Cong D Z, Fang T N, et al. Principles of Chemical Engineering[M]. 3rd ed. Beijing: Chemical Industry Press, 2006.
24	邵青楠, 迟子怡, 李学刚, 等. 铁钼法甲醇制甲醛催化动力学研究及反应器模拟[J]. 天然气化工(C1化学与化工), 2021, 46(5): 121-128.
	Shao Q N, Chi Z Y, Li X G, et al. Kinetic study and reactor simulation of methanol to formaldehyde over Fe-Mo catalysts[J]. Natural Gas Chemical Industry, 2021, 46(5): 121-128.
25	Borio D O, Gatica J E, Porras J A. Wall-cooled fixed-bed reactors: parametric sensitivity as a design criterion[J]. AIChE Journal, 1989, 35(2): 287-292.
26	Kummer A, Varga T. What do we know already about reactor runaway? A review[J]. Process Safety and Environmental Protection, 2021, 147: 460-476.
27	Adler J, Enig J W. The critical conditions in thermal explosion theory with reactant consumption[J]. Combustion and Flame, 1964, 8(2): 97-103.
28	Ergun S. Fluid flow through packed columns[J]. Fluid Flow Through Packed Columns, 1952, 48: 89-94.
29	Partopour B, Dixon A G. Effect of particle shape on methanol partial oxidation in a fixed bed using CFD reactor modeling[J]. AIChE Journal, 2020, 66(5): e16904.
30	Liu X L, Qin B, Zhang Q F, et al. Optimizing catalyst supports at single catalyst pellet and packed bed reactor levels: a comparison study[J]. AlChE Journal, 2021, 67(8): e17163.
31	Zhang M H, Dong H, Geng Z F. A particle-resolved CFD model coupling reaction-diffusion inside fixed-bed reactor[J]. Advanced Powder Technology, 2019, 30(6): 1226-1238.

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