Design and optimization of cryogenic air separation process with dividing wall column based on self-heat regeneration

doi:10.11949/0438-1157.20230240

Abstract

Abstract:

Industrial gases commonly obtained by cryogenic distillation are widely used currently. The energy consumption of the process is always huge, and the energy consumption of compression and rectification accounts for the largest proportion. A cryogenic air separation process with a dividing wall column was proposed based on the self-heat regeneration, in which the double-tower distillation air separation process was replaced by a single-tower distillation process applying the self-heat regeneration technology to complete the process of heat exchange. The energy of the process was analyzed by the pinch principle, and the total energy consumption (TEC), carbon dioxide emissions ([CO₂]_em), and total annual cost (TAC) were evaluated, respectively. The results showed the cryogenic air separation process based on the self-heating regeneration in the dividing wall column reduced energy consumption for oxygen production by 26.19%, CO₂ emission by 25.18%, and the TAC by 31.93%. The optimized air separation process using self-heat regeneration technology and dividing wall column technology has shown stronger advantages in energy saving, economy, and environmental protection.

Key words: self-heat regeneration, dividing wall column, air separation, computer simulation, optimal design, systemic energy saving

摘要：

工业气体应用广泛，当前常用深冷精馏法获取，工艺能耗巨大，其中压缩和精馏部分的耗能占比最大。基于自热再生和隔壁塔技术，提出了一种隔壁塔深冷空分方案，用单塔精馏空分过程代替双塔精馏空分过程，利用自热再生优化过程换热。利用夹点原理对优化前后的工艺进行能量分析，并从总能量消耗（TEC）、二氧化碳排放量（[CO₂]_em）、年度总费用（TAC）三个角度分别进行评价。结果表明，基于自热再生的隔壁塔深冷空分工艺较常规空分工艺，制氧消耗降低了26.19%，二氧化碳排放减少了25.18%，年度总费用降低了31.93%。利用自热再生技术和隔壁塔技术优化后的空分工艺，在节能、经济以及环保方面表现出更强的优越性。

关键词: 自热再生, 隔壁塔, 空气分离, 计算机模拟, 优化设计, 系统节能

CLC Number:

TQ 015.2

Zhaolun WEN, Peirui LI, Zhonglin ZHANG, Xiao DU, Qiwang HOU, Yegang LIU, Xiaogang HAO, Guoqing GUAN. Design and optimization of cryogenic air separation process with dividing wall column based on self-heat regeneration[J]. CIESC Journal, 2023, 74(7): 2988-2998.

文兆伦, 李沛睿, 张忠林, 杜晓, 侯起旺, 刘叶刚, 郝晓刚, 官国清. 基于自热再生的隔壁塔深冷空分工艺设计及优化[J]. 化工学报, 2023, 74(7): 2988-2998.

Figures/Tables 18

Table 1 Feeding conditions of raw materials

温度/℃	压力/kPa	空气处理/（m³/h,标准工况）	组成/%（mol）
温度/℃	压力/kPa	空气处理/（m³/h,标准工况）	氮气	氧气	氩气
25	101	166900	0.7809	0.2095	0.0096

Fig.1 Process flowsheet of conventional double-tower distillation air separation process

Table 2 Parameters of traditional air separation distillation column

参数	上塔	下塔	粗氩塔	精氩塔
理论级数	55	35	80	38
进料位置	1/8/22/25/28/33/55	1/35	1/80	1/38
产品抽出位置	1/23/28/55	1/21/35	1/80	1/38
塔顶温度/℃	-192.17	-178.04	-191.64	-192.17
塔底温度/℃	-179.33	-174.27	-185.65	-182.00
操作压力/kPa	150	540	150	150

Fig.2 T-Q diagram of conventional double-tower distillation based air separation process

Fig.3 Partial distillation stage diagram of air separation process

Fig.4 Process flowsheet of single-tower distillation based air separation process in dividing wall column

Fig.5 Influence of extraction position of side line of crude argon gas on product purity in process

Fig.6 Influence of extraction position of side line of polluted nitrogen gas on product purity

Fig.7 Influence of the number of crude argon tower trays on product purity

Fig.8 Influence of the number of pure argon tower trays on product purity

Fig.9 Influence of the number of main distillation tower trays on product purity

Fig.10 Flow chart of air separation optimization in dividing wall column

Fig.11 Influence of production position of crude argon side line on annual total cost

Fig.12 Influence of lateral production location of polluted nitrogen on annual total cost

Table 3 Analysis of economic optimization results of single-tower distillation based air separation process in dividing wall column

参数	数值
N_VR	23
N_WN	9
N_T1	110
N_T2	70
N_T3	38
TAC/ $(106 U S D / a)$	10.06

Table 3 Analysis of economic optimization results of single-tower distillation based air separation process in dividing wall column

参数	数值
N_VR	23
N_WN	9
N_T1	110
N_T2	70
N_T3	38
TAC/ $(106 U S D / a)$	10.06

Fig.13 T-Q diagram of single-tower distillation based air separation process with dividing wall column

Table 4 Comparison of design parameters

产品名称	产量/(m³/h,标准工况)			纯度/%
产品名称	企业生产数据	常规双塔空分	隔壁单塔空分	纯度/%
空气	165800	166900	166900	—
氧气	30000	34800	34900	>99.6
氮气	17350	63000	63000	>99.99
氩气	670	1030	1100	>99.999
制氧能耗/ (kW∙h/m³,标准工况)	0.43	0.42	0.31	—

Table 5 Comparison of simulated result

参数	常规双塔空分	隔壁单塔空分
精馏塔费用/(10⁵ USD/a)	3.09	3.96
换热器费用/(10⁶ USD/a)	4.87	1.95
压缩机费用/(10⁶ USD/a)	9.61	7.73
总投资费用/(10⁷ USD/a)	3.10	2.77
总运行费用/(10⁷ USD/a)	1.09	0.66
压缩机能耗/kW	14470	10827
冷却器能耗/kW	12325	6194
总耗能 $T E C$ /kW	43410	32481
二氧化碳排放量/(kg/h)	4078	3051
年度总费用TAC/(10⁶ USD/a)	14.78	10.06
设备折旧年限/a	8	8

Table 5 Comparison of simulated result

参数	常规双塔空分	隔壁单塔空分
精馏塔费用/(10⁵ USD/a)	3.09	3.96
换热器费用/(10⁶ USD/a)	4.87	1.95
压缩机费用/(10⁶ USD/a)	9.61	7.73
总投资费用/(10⁷ USD/a)	3.10	2.77
总运行费用/(10⁷ USD/a)	1.09	0.66
压缩机能耗/kW	14470	10827
冷却器能耗/kW	12325	6194
总耗能 $T E C$ /kW	43410	32481
二氧化碳排放量/(kg/h)	4078	3051
年度总费用TAC/(10⁶ USD/a)	14.78	10.06
设备折旧年限/a	8	8

References 39

1	王莉君. 空分产品的应用领域及其发展探索[J]. 化工管理, 2019(20): 7-8.
	Wang L J. Application field and development exploration of air separation products[J]. Chemical Enterprise Management, 2019(20): 7-8.
2	He X F, Liu Y N, Rehman A, et al. A novel air separation unit with energy storage and generation and its energy efficiency and economy analysis[J]. Applied Energy, 2021, 281: 115976.
3	智研咨询. 2021年中国气体分离设备行业运营情况分析: 气体分离及液化设备产量 14.85万台[EB/OL]. [2022-05]. .
	Intelligence Research Group. Analysis of the operation of China's gas separation equipment industry in 2021: the output of gas separation and liquefaction equipment was 148,500 units [EB/OL]. [2022-05]. .
4	彭相磊. 兖矿国宏30000 Nm³/h空分净化装置节能和优化[D]. 天津: 天津大学, 2012.
	Peng X L. Yankuang Guohong 30000 Nm³/h air separation purification device energy saving optimization[D]. Tianjin: Tianjin University, 2012.
5	Smith A R, Klosek J. A review of air separation technologies and their integration with energy conversion processes[J]. Fuel Processing Technology, 2001, 70(2): 115-134.
6	杨尚宇. 空分装置变负荷操作的模拟与优化[D]. 包头: 内蒙古科技大学, 2020.
	Yang S Y. Simulation and optimization of variable load operation in air separation unit[D]. Baotou: Inner Mongolia University of Science & Technology, 2020.
7	Ebrahimi A, Ziabasharhagh M. Optimal design and integration of a cryogenic air separation unit (ASU) with liquefied natural gas (LNG) as heat sink, thermodynamic and economic analyses[J]. Energy, 2017, 126: 868-885.
8	郑捷宇, 厉彦忠, 司标, 等. 基于㶲分析的空分流程对比研究[J]. 工程热物理学报, 2015, 36(10): 2097-2101.
	Zheng J Y, Li Y Z, Si B, et al. Comparative study of air separation process based on exergy analysis[J]. Journal of Engineering Thermophysics, 2015, 36(10): 2097-2101.
9	Taniguchi Masaaki, 张应武, 刘有存. 基于㶲分析的节能型空分装置[J]. 钢铁译文集, 2016(1): 58-62.
	Taniguchi M, Zhang Y W, Liu Y C. Energy saving air-seperation plant based on exergy analysis [J]. Collection of steel translations, 2016(1): 58-62.
10	Kender R, Rößler F, Wunderlich B, et al. Improving the load flexibility of industrial air separation units using a pressure-driven digital twin[J]. AIChE Journal, 2022, 68(7): e17692.
11	Asma-ul-Husna, Hasan R, Rashid S A, et al. Energy saving in cryogenic air separation process applying self-heat recuperation technology[C]//Proceedings of the International Conference on Mechanical Engineering and Renewable Energy 2015. Chittagong, Bangladesh, 2015.
12	Janusz-Szymańska K, Dryjańska A. Possibilities for improving the thermodynamic and economic characteristics of an oxy-type power plant with a cryogenic air separation unit[J]. Energy, 2015, 85: 45-61.
13	叶青, 裘兆蓉, 韶晖, 等. 热偶精馏技术与应用进展[J]. 天然气化工, 2006, 31(4): 53-56, 65.
	Ye Q, Qiu Z R, Shao H, et al. Progress in the technology and application of thermally coupled distillation [J]. Natural Gas Chemistry, 2006, 31(4): 53-56, 65.
14	马晨皓, 曾爱武. 隔壁塔流程模拟及节能效益的研究[J]. 化学工程, 2013, 41(3): 1-5, 15.
	Ma C H, Zeng A W. Simulation of dividing-wall-column process and its energy-saving benefits[J]. Chemical Engineering(China), 2013, 41(3): 1-5, 15.
15	陈梦琪. 热泵常规隔壁塔与热泵共沸精馏隔壁塔的控制研究[D]. 东营: 中国石油大学(华东), 2018.
	Chen M Q. Control of heat pump assisted conventional and azeotropic dividing wall columns[D]. Dongying: China University of Petroleum, 2018.
16	Kender R, Rößler F, Wunderlich B, et al. Development of control strategies for an air separation unit with a divided wall column using a pressure-driven digital twin[J]. Chemical Engineering and Processing-Process Intensification, 2022, 176: 108893.
17	裘兆蓉, 叶青, 李成益. 国内外分隔壁精馏塔现状与发展趋势[J]. 江苏工业学院学报, 2005, 17(1): 58-61.
	Qiu Z R, Ye Q, Li C Y. Status and development trends of dividing wall column at home and abroad[J]. Journal of Jiangsu Polytechnic University, 2005, 17(1): 58-61.
18	张月明. 隔壁精馏塔技术应用于反应精馏及空气分离的研究[D]. 青岛: 中国石油大学, 2010.
	Zhang Y M. Study on the application of dividing wall column to the reactive distillation and air separation[D]. Qingdao: China University of Petroleum, 2010.
19	马占华, 翟诚, 李军,等. 隔壁式空分精馏塔应用性能研究[J]. 化学工程, 2012, 40(2): 1-6.
	Ma Z H, Zhai C, Li J, et al. Application of air separation dividing wall column[J]. Chemical Engineering (China), 2012, 40(2): 1-6.
20	Kansha Y, Tsuru N, Sato K, et al. Self-heat recuperation technology for energy saving in chemical processes[J]. Industrial & Engineering Chemistry Research, 2009, 48(16): 7682-7686.
21	陈东良, 张忠林, 杨景轩, 等. 基于自热再生的化学吸收法CO₂捕集工艺模拟及节能分析[J]. 化工学报, 2019, 70(8): 2938-2945.
	Chen D L, Zhang Z L, Yang J X, et al. Process simulation and energy saving analysis of CO₂ capture by chemical absorption method based on self-heat recuperation[J]. CIESC Journal, 2019, 70(8): 2938-2945.
22	Fushimi C, Kansha Y, Aziz M, et al. Novel drying process based on self-heat recuperation technology[J]. Drying Technology, 2010, 29(1): 105-110.
23	白桂培, 韩东, 姚瑶, 等. 基于自回热原理的木材干燥过程的热力学分析[J]. 能源化工, 2017, 38(2): 1-7.
	Bai G P, Han D, Yao Y, et al. Thermodynamic analysis of wood drying process based on self-heat recuperation technology[J]. Energy Chemical Industry, 2017, 38(2): 1-7.
24	Kansha Y, Kishimoto A, Tsutsumi A. Application of the self-heat recuperation technology to crude oil distillation[J]. Applied Thermal Engineering, 2012, 43: 153-157.
25	陈昱珍. 自热再生技术在原油蒸馏装置中的应用研究[D]. 哈尔滨: 哈尔滨工业大学, 2015.
	Chen Y Z. The application of self-heat recuperation technology in crude oil distillation units[D]. Harbin: Harbin Institute of Technology, 2015.
26	Fu Q, Zhai R R, Feng L J, et al. Performance analysis of the acid gas removal from syngas based on self-heat recuperation technology[J]. Applied Thermal Engineering, 2023, 219: 119506.
27	Fu Q, Kansha Y, Song C F, et al. An advanced cryogenic air separation process based on self-heat recuperation for CO₂ separation[J]. Energy Procedia, 2014, 61: 1673-1676.
28	Fu Q, Kansha Y, Song C F, et al. A cryogenic air separation process based on self-heat recuperation for oxy-combustion plants[J]. Applied Energy, 2016, 162: 1114-1121.
29	Fu Q, Kansha Y, Song C F, et al. An elevated-pressure cryogenic air separation unit based on self-heat recuperation technology for integrated gasification combined cycle systems[J]. Energy, 2016, 103: 440-446.
30	Lin B S, Malmali M. Energy and exergy analysis of multi-stage vacuum membrane distillation integrated with mechanical vapor compression[J]. Separation and Purification Technology, 2023, 306: 122568.
31	邹环泽. 深冷空分的过程模拟与节能分析[D]. 重庆: 重庆大学, 2017.
	Zou H Z. The simulation and analysis of the process cryogenic air separation[D]. Chongqing: Chongqing University, 2017.
32	杨泽萌, 韩晓萌, 卢新发. 基于稳态模拟技术的空分增氮工艺流程设计与实施[J]. 冶金动力, 2022, 41(1): 39-42.
	Yang Z M, Han X M, Lu X F. Design and implementation of air separation nitrogen increase process based on steady-state simulation technology[J]. Metallurgical Power, 2022, 41(1): 39-42.
33	Saedi M, Mehrpooya M, Shabani A, et al. Proposal and investigation of a novel process configuration for production of neon from cryogenic air separation unit[J]. Sustainable Energy Technologies and Assessments, 2022, 50: 101875.
34	Li J E, Zhang F J, Pan Q, et al. Performance enhancement of reactive dividing wall column based on self-heat recuperation technology[J]. Industrial & Engineering Chemistry Research, 2019, 58(27): 12179-12191.
35	Douglas J M. Conceptual Design of Chemical Processes[M]. New York: McGraw-Hill Book Company, 1988: 30-216.
36	Yu H, Ye Q, Xu H, et al. Design and control of dividing-wall column for tert-butanol dehydration system via heterogeneous azeotropic distillation[J]. Industrial & Engineering Chemistry Research, 2015, 54(13): 3384-3397
37	刘叶刚, 张忠林, 侯起旺, 等. TBCFB合成气制甲醇工艺过程的概念设计和计算机模拟[J]. 化工学报, 2021, 72(9): 4838-4846.
	Liu Y G, Zhang Z L, Hou Q W, et al. Process design and simulation of synthesis gas to methanol in TBCFB system [J]. CIESC Journal, 2021, 72(9): 4838-4846.
38	An D C, Cai W F, Xia M, et al. Design and control of reactive dividing-wall column for the production of methyl acetate[J]. Chemical Engineering and Processing: Process Intensification, 2015, 92: 45-60.
39	田奇琦. 大型空气分离系统建模与低能耗化研究[D]. 武汉: 华中科技大学, 2016.
	Tian Q Q. A study on modeling large-scale air separation units and low energy consumption[D]. Wuhan: Huazhong University of Science and Technology, 2016.

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