纯氧克劳斯工艺的模拟与优化

高德志; 喻昕蕾; 陶迅; 丁路; 代正华; 王辅臣

doi:10.14135/j.cnki.1006-3080.20201204003

纯氧克劳斯工艺的模拟与优化

doi: 10.14135/j.cnki.1006-3080.20201204003

华东理工大学上海市煤气化工程技术研究中心，上海 200237

基金项目: 国家自然科学基金(21978092)

详细信息

作者简介:
高德志(1996—)，男，福建泉州人，硕士生，研究方向为克劳斯工艺流程模拟与优化研究。E-mail：623686540@qq.com

通讯作者:
王辅臣，E-mail：wfch@ecust.eud.cn

中图分类号: TQ125.11
计量
- 文章访问数: 334
- HTML全文浏览量: 272
- PDF下载量: 11
- 被引次数: 0
出版历程
- 收稿日期: 2020-12-04
- 网络出版日期: 2021-01-25

Simulation and Optimization of Pure Oxygen Claus Process

Shanghai Engineering Research Center of Coal Gasification, East China University of Science and Technology, Shanghai 200237, China

摘要

摘要: 克劳斯工艺是高效处理H₂S等酸性气体并回收硫磺的技术之一。工业过程处理低浓度酸性气体时，需要加入助燃气体以保证火焰稳定，但会导致多环芳烃、有机硫等有害物质的量增加。而采用纯氧燃烧，则可在无需引入助燃气体的情况下提高炉膛温度、增加烃类杂质的去除率。论文基于Aspen plus软件建立克劳斯工艺全流程模型，使用某工厂数据进行验证，探究了进口酸气组成、氧气浓度及进气量、氧气预热温度、炉膛压力及第二催化段反应器温度对于克劳斯工艺的影响，并以硫收率为目标函数利用Aspen plus优化工具计算了最佳操作参数。优化结果表明：硫收率从98.31%提高到99.08%，尾气中主要污染物SO₂的排放量由0.350 kmol/h减少至0.278 kmol/h，降低了20.6%，并节约了酸性气体和空气预热所需的热量9133.38 kJ/(kmol酸性气体)。
- 克劳斯工艺 /
- 低浓度酸性气体 /
- 纯氧 /
- 流程模拟 /
- 优化研究
Abstract: The Claus process is one of the technologies for efficient acid gas processing and sulfur recovering. In industry, it is necessary to add combustion-supporting gas for combustion to ensure flame stability when processing low concentration acid gas, which leads to problems such as increased production of harmful substances like polycyclic aromatic hydrocarbons and organic sulfur. The use of pure oxygen for combustion can not only increase the temperature of the furnace and the removal rate of hydrocarbon impurities, but also avoid the problems caused by the addition of combustion-supporting gas. In this paper, a full Claus process model was built in the Aspen Plus and was validated by industrial data. The influence of the inlet acid gas composition, oxygen concentration, oxygen preheating temperature, furnace pressure, oxygen gas intake and the temperature of the second catalytic stage reactor on the Clause process were studied. The optimization tool in Aspen Plus was used to calculate the best operating parameters. The optimized results showed that the sulfur recovery efficiency increased from 98.31% — 99.08% and the emission of SO₂, the main pollutant in the tail gas, reduced from 0.350 kmol/h to 0.278 kmol/h, reduction rate at 20.6%. Moreover, it saved 9133.38 kJ/kmol(acid gas) heat required for the preheating of the acid gas and air.
- Claus process /
- low concentration acid gas /
- pure oxygen /
- process simulation /
- optimization study

HTML全文

图 1 Aspen plus克劳斯硫回收过程流程图

Figure 1. A schematic diagram of the Claus process in Aspen plus

下载: 全尺寸图片幻灯片

图 2 氧气摩尔分数对克劳斯硫回收过程的影响

Figure 2. Effect of oxygen molar fraction on the performance of the Claus process

下载: 全尺寸图片幻灯片

图 3 氧气摩尔分数对n(H₂S)/n(SO₂)的影响

Figure 3. Effect of oxygen molar fraction on the n(H₂S)/n(SO₂)

下载: 全尺寸图片幻灯片

图 4 α对克劳斯硫回收过程的影响

Figure 4. Effect of α on the performance of the Claus process

下载: 全尺寸图片幻灯片

图 5 α对总硫收率和第一催化段出口处n(H₂S)/n(SO₂)的影响

Figure 5. Effect of α on the performance of the sulfur recovery efficiency and n(H₂S)/n(SO₂) of first catalysis stage

下载: 全尺寸图片幻灯片

图 6 氧气预热温度对克劳斯硫回收过程的影响

Figure 6. Effect of oxygen preheating temperature on the performance of the Claus process

下载: 全尺寸图片幻灯片

图 7 炉膛压力对克劳斯硫回收过程总硫收率的影响

Figure 7. Effect of furnace pressure on the sulfur recovery efficiency of the Claus process

下载: 全尺寸图片幻灯片

图 8 第二催化段反应器温度对克劳斯硫回收过程的影响

Figure 8. Effect of second catalysis stage reaction temperature on the performance of the Claus process

下载: 全尺寸图片幻灯片

表 1 进料气组分摩尔分数

Table 1. Gas molar composition of the inlet

Gas	Molar fraction/%
Gas	AG1	AG2	AG3	AIR1
H₂	0	0.50	12.40	0
Ar	0	0	0.20	0.93
N₂	29.00	20.00	0.20	78.09
CO	0	0.50	8.00	0
CO₂	20.00	67.00	75.00	0.03
H₂S	50.00	2.00	1.00	0
H₂O	0	0	3.00	0
NH₃	0	0	0.20	0
O₂	0	0	0	20.95
CH₃OH	1.00	10.00	0	0

下载: 导出CSV

表 2 RF1考虑的反应

Table 2. Considered reactions in RF1

Reaction	No.
$ {\rm{N}}{{\rm{H}}}_{3} \to {\rm{0.5N}}_{{2}}{+1.5}{{\rm{H}}}_{{2}} $	R1
$ {{\rm{H}}_2}{\rm{S + 1}}{\rm{.5}}{{\rm{O}}_2} \to {{\rm{H}}_2}{\rm{O + S}}{{\rm{O}}_2}$	R2

下载: 导出CSV

表 3 RF2内考虑的反应及其动力学参数

Table 3. Kinetic parameters and reactions of RF2

Reaction	Reaction rate expressions	No.	Reference
${{\rm{H}}_{\rm{2}}}{\rm{S}} \leftrightarrow {{\rm{H}}_{\rm{2}}}{\rm{ + 0}}{\rm{.5}}{{\rm{S}}_{\rm{2}}}$	$-{r_{ {\rm{ {H} }_2s} } }=1.63\times{10^{-1} }{ {\rm{e} }^{\dfrac{ {45.1} }{ {RT} } } }{P_{\rm{ { {H} }_2}S} }P_{\rm{S_2} }^{0.5}-1.36\times{10^{-6} }{ {\rm{e} }^{\dfrac{ {23.4} }{ {RT} } } }{P_{\rm{H_2} } }{P_{\rm{S_2} } }$	R3	[19]
${\rm{CO} } + 0.5{{\rm{S}}_2} \leftrightarrow {\rm{COS}}$	$- {r_{ {\rm{CO} } } } = 3.18\times {10^5}{ {\rm{e} }^{\dfrac{ {15.3} }{ {RT } } } }\left( { {c_{\rm{CO} } }{c_{ { {\rm{S} }_2} } } - \dfrac{1}{ { {k_{\rm{eq2} } } } }{c_{\rm{COS} } }c_{ { {\rm{S} }_2} }^{0.5} } \right)$	R4	[20]
$ {\rm{C}}{{\rm{O}}_{\rm{2}}}{\rm{ + }}{{\rm{H}}_{\rm{2}}} \leftrightarrow {\rm{CO + }}{{\rm{H}}_{\rm{2}}}{\rm{O}}$	$-{r_{\rm{C{O_2} } } }=8.59\times{10^{10} }{ {\rm{e} }^{\dfrac{ {64.7} }{ {RT} } } }\left( { {c_{\rm{C{O_2} }} }c_{ {\rm{ {H} }_2} }^{0.5}-\dfrac{1}{ {\rm{k_{eq3} } } }\dfrac{ { {c_{\rm{CO} } }{c_{ {\rm{ {H} }_2O} } } } }{ {c_{ {\rm{ {H} }_2} }^{0.5} } } } \right)$	R5	[21]
$ {\rm{CO + }}{{\rm{H}}_{\rm{2}}}{\rm{S}} \leftrightarrow {\rm{COS + }}{{\rm{H}}_{\rm{2}}} $	$-r{\rm{_{CO} } }=1.59\times{10^5}{ {\rm{e} }^{\dfrac{ {26.5} }{ {RT} } } }\left({ {c_{\rm{CO} } }c_{ {\rm{ {H} }_2S} }^{0.5}-\dfrac{1}{ {\rm{k_{eq4} } } }\dfrac{ { {c_{\rm{COS} } }{c_{ {\rm{ {H} }_2} } } } }{ {c_{ {\rm{ {H} }_2S}}^{0.5} } } }\right)$	R6	[22]
$ {{\rm{H}}_{\rm{2}}}{\rm{S + 0}}{\rm{.5S}}{{\rm{O}}_{\rm{2}}} \leftrightarrow {\rm{0}}{\rm{.75}}{{\rm{S}}_{\rm{2}}}{\rm{ + }}{{\rm{H}}_{\rm{2}}}{\rm{O}}$	$-{r_{ {\rm{ {H} }_2}S} }=3.18\times{10^3}{ {\rm{e} }^{\dfrac{ {14.3} }{ {RT} } } }{c_{ {\rm{ {H} }_2S}} }c_{\rm{S{O_2} } }^{0.5}-3.11\times{10^1}{ {\rm{e} }^{\dfrac{ {8.5} }{ { {RT} } } }}{c_{\rm{ { { {H} }_2}O} } }c_{ {\rm{S_2} } }^{0.75}$	R7	[23]

下载: 导出CSV

表 4 炉膛出口气模拟结果与工厂工况比较结果

Table 4. Simulated results versus plant data for composition of gas from furnace

Gas	q/(kmol·h⁻¹)
Gas	Plant date	Simulated results	Absolute error/%
H₂	1.636	1.698	3.81
Ar	0.600	0.600	0.01
N₂	63.453	63.448	0.01
CO	1.038	1.233	18.77
CO₂	27.079	26.868	0.78
H₂S	9.155	9.175	0.22
COS	0.119	0.133	12.13
SO₂	4.637	4.789	3.27
H₂O	17.930	17.836	0.53
S₂	5.458	5.387	1.31

下载: 导出CSV

表 5 优化结果与运行工况重要参数比较

Table 5. Important parameters of the optimization results compared with operating condition’s

Important parameters	Operating parameters	Optimization results
x(O₂)/%	20.95	99.60
Split ratio	0.80	1.00
Air molar flow/kmol·h⁻¹	60.90	14.09
T₀/℃	80.00	25.00
T_a/℃	240.00	25.00
T_s/℃	218.00	180.00
T_f/℃	1019.39	1314.11
Y_S/%	98.31	99.08
n(H₂S)/n(SO₂) of first catalysis stage	1.99	2.00
Outlet SO₂ mole flow of off-gas/kmol·h⁻¹	0.350	0.278

下载: 导出CSV

参考文献(25)

[1]	GUPTA A K, IBRAHIM S, SHOAIBI A A. Advances in sulfur chemistry for treatment of acid gases[J]. Progress in Energy and Combustion Science, 2016, 54: 65-92. doi: 10.1016/j.pecs.2015.11.001
[2]	MAHDIPOOR H R, ASHKEZARI A D. Feasibility study of a sulfur recovery unit containing mercaptans in lean acid gas feed[J]. Journal of Natural Gas Science and Engineering, 2016, 31: 585-588. doi: 10.1016/j.jngse.2016.03.045
[3]	BASSANI A, PIROLA C, BOZZANO G, et al. Technical Feasibility of AG2S™ Process Revamping[J]. Computer Aided Chemical Engineering, 2017, 40: 385-390. doi: 10.1016/B978-0-444-63965-3.50066-0
[4]	陈赓良, 肖学兰, 杨仲熙, 等. 克劳斯法硫磺回收工艺技术[M]. 北京: 石油工业出版社, 2007.
[5]	MANENT F, PAPASODERO D, BOZZANO G, et al. Model-based optimization of sulfur recovery units. 2014, 66: 244-251.
[6]	ZAREI S. Life cycle assessment and optimization of Claus reaction furnace through kinetic modeling[J]. Chemical Engineering Research and Design, 2019, 148: 75-85. doi: 10.1016/j.cherd.2019.06.005
[7]	DUSTIN D J. Steady state and dynamic modeling of the modified Claus process as part of an IGCC power plant[D]. American: West Virginia University, 2011.
[8]	MOHAMMED S, RAJ A, SHOAIBI A A. Effects of fuel gas addition to Claus furnace on the formation of soot precursors[J]. Combustion and Flame, 2016, 168: 240-254. doi: 10.1016/j.combustflame.2016.03.008
[9]	ASADI S, PAKIZEH M, CHENAR M P. An investigation of reaction furnace temperatures and sulfur recovery[J]. Frontiers of Chemical Engineering in China, 2011, 5(3): 362-371.
[10]	RAHMAN R K, IBRAHIM S, RAJ A. Oxidative destruction of monocyclic and polycyclic aromatic hydrocarbon (PAH) contaminants in sulfur recovery units[J]. Chemical Engineering Science, 2016, 155: 348-365. doi: 10.1016/j.ces.2016.08.027
[11]	CHARDONNEAUA M, IBRAHIM S, GUOTA A K, et al. Role of toluene and carbon dioxide on sulfur recovery efficiency in a Claus process[J]. Energy Procedia, 2015, 75: 3071-3075. doi: 10.1016/j.egypro.2015.07.630
[12]	SELIM H, GUPTA A K, SHOAIBI A A. Effect of CO₂ and N₂ concentration in acid gas stream on H₂S combustion[J]. Applied Energy, 2012, 98: 53-58. doi: 10.1016/j.apenergy.2012.02.072
[13]	IBRAHIM S, RAHMAN R K, RAJ A. Effects of H₂O in the feed of sulfur recovery unit on sulfur production and aromatics emission from Claus furnace[J]. Industrial and Engineering Chemistry Research, 2017, 56(41): 11713-11725. doi: 10.1021/acs.iecr.7b02553
[14]	IBRAHIM S, RAHMAN R K, RAJ A. Roles of hydrogen sulfide concentration and fuel gas injection on aromatics emission from Claus furnace[J]. Chemical Engineering Science, 2017, 172: 513-527. doi: 10.1016/j.ces.2017.06.050
[15]	LIi Y, YU X, LI H, et al. Detailed kinetic modeling of H₂S oxidation with presence of CO₂ under rich condition[J]. Applied Energy, 2017, 190: 824-834. doi: 10.1016/j.apenergy.2016.12.150
[16]	LI Y, GUO Q, YU X, et al. Effect of O₂ enrichment on acid gas oxidation and formation of COS and CS₂ in a rich diffusion flame[J]. Applied Energy, 2017, 206: 905-958.
[17]	LI Y, YU X, GUO Q, et al. Detailed kinetic modeling of homogeneous H₂S-CH₄ oxidation under ultra-rich condition for H₂ production[J]. Applied Energy, 2017, 208: 905-919. doi: 10.1016/j.apenergy.2017.09.059
[18]	KAZEMPOUR H, POURFAYAZ F, MEHRPOOYA M. Modeling and multi-optimization of thermal section of Claus process based on kinetic model[J]. Journal of Natural Gas Science and Engineering, 2017, 38: 235-244. doi: 10.1016/j.jngse.2016.12.038
[19]	HAWBOLDT, K. A., MONNERY, W D, SVRCEK W Y New experimental data and kinetic rate expression for H₂S pyrolysis and re-association[J]. Chemical Engineering Science, 2000, 55(5): 957-966. doi: 10.1016/S0009-2509(99)00366-8
[20]	KARAN K, MEHROTRA A K, BEHIE L A. COS-forming reaction between CO and sulfur: A high-temperature intrinsic kinetics study[J]. Industrial and Engineering Chemistry Research, 1998, 37(12): 4609-4616. doi: 10.1021/ie9802966
[21]	KARAN K. An experimental and modeling study of homogeneous gas phase reactions occurring in the modified Claus process[D]. Canada: University of Calgary, 1998.
[22]	KARAN K, MEHROTRA A K, BEHIE L A. A high-temperature experimental and modeling study of homogeneous gas-phase COS reactions applied to Claus plants[J]. Chemical Engineering Science, 1999, 54(16): 2999-3006.
[23]	TESNER P, NEMIROVSKII M, MOTYL D. Kinetics of the thermal decomposition of hydrogen sulfide at 600—1200 ℃[J]. Kinetics and Catalysis, 1990, 31: 1081-1083.
[24]	GAMSON B W, ELKNS R H. Sulfur from hydrogen sulfide[J]. Chemical Engineering Process, 1953, 49(4): 203-205.
[25]	王青, 余小光, 乔明杰, 等. 基于序列二次规划算法的定位器坐标快速标定方法[J]. 浙江大学学报(工学版), 2017, 51(2): 319-327.