CIESC Journal ›› 2022, Vol. 73 ›› Issue (1): 308-321.DOI: 10.11949/0438-1157.20211103

• Separation engineering • Previous Articles     Next Articles

Transient analysis of pressure swing adsorption hydrogen purification process

Chao ZHANG1(),Jian CHEN2,Wenhua YIN2,Yuanhui SHEN1,Zhaoyang NIU1,Xiuxin YU1,Donghui ZHANG1(),Zhongli TANG1   

  1. 1.State Key Laboratory of Chemical Engineering, Chemical Engineering Research Center, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China
    2.Southwest Institute of Chemical Co. , Ltd. , Chengdu 610225, Sichuan, China
  • Received:2021-08-09 Revised:2021-11-23 Online:2022-01-18 Published:2022-01-05
  • Contact: Donghui ZHANG

变压吸附氢气纯化过程瞬态分析

张超1(),陈健2,殷文华2,沈圆辉1,钮朝阳1,余秀鑫1,张东辉1(),唐忠利1   

  1. 1.天津大学化工学院,化学工程研究所,化学工程联合国家重点实验室,天津 300350
    2.西南化工研究设计院有限公司,四川 成都 610225
  • 通讯作者: 张东辉
  • 作者简介:张超(1998—),男,硕士研究生,zhang_chao@tju.edu.cn
  • 基金资助:
    国家重点研发计划项目(2019YFB1505000)

Abstract:

Pressure swing adsorption (PSA) is one of the most common technologies to produce high-purity hydrogen in the industry. However, in the actual production process, the distribution state of each component in the bed at different time cannot be observed. For this reason, simulation methods are used to study the dynamic change of each component in the bed from the feeding to the system reaching the steady state, which is essential to guide process improvement. In this study, an eight-bed PSA process was designed to purify hydrogen from steam methane reforming (SMR) gas and the activated carbon and 5A zeolite were used as adsorbent. The start-up procedure of PSA hydrogen production was performed, and the transient adsorption behaviors of each component in the bed during the three stages of adsorption, sequential release and flushing, as well as the transient adsorption behavior during the adsorption stage and the temperature variation in the bed after the system reached the cyclic steady state were analyzed. The results show that the heavy components move towards the top of the bed with the cycle during the adsorption as well as the sequential release. This phenomenon is the result of both inter-component competition for adsorption and the accumulation of fractions at the bottom of the bed in the flush regeneration mode. These factors can also, to some extent, cause the adsorption front of CO to enter too much on the 5A zeolite during the adsorption phase, making the CO content become a major limiting factor for process performance.

Key words: pressure swing adsorption, activated carbon, 5A zeolite, hydrogen production, numerical simulation, transient analysis

摘要:

变压吸附技术是工业上生产高纯氢气最常用的方法之一。然而,在实际生产过程中无法观察到塔内各组分在不同时刻的分布状态,因此借助模拟的手段来研究从投料至系统达到循环稳态期间各组分在塔内的动态变化规律,进而指导工艺改进是很有必要的。采用活性炭和5A分子筛为吸附剂,设计了八塔变压吸附工艺从蒸汽甲烷重整气中纯化氢气,模拟了变压吸附制氢开车过程,分析了开车过程中塔内各组分在吸附、顺放以及冲洗三个阶段以及循环稳态后吸附阶段瞬态吸附行为和塔内温度变化。结果表明,在吸附以及顺放等过程中重组分会随着循环周期向塔顶移动。这一现象是组分间竞争吸附和冲洗再生方式下重组分在床层底部累积两个作用因素共同导致的。这些因素在一定程度上也会造成CO的吸附前沿在吸附阶段就过多进入5A分子筛上,使得CO含量成为限制工艺性能的主要因素。

关键词: 变压吸附, 活性炭, 5A分子筛, 制氢, 数值模拟, 瞬态分析

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