炼油技术与工程 ›› 2025, Vol. 55 ›› Issue (4): 15-18.

• 加工工艺 • 上一篇    下一篇

液化石油气脱硫醇装置碱液再生尾气治理

刘健，刁青国，孙克文，王鹏   

  1. 中国石油化工股份有限公司济南分公司，山东省济南市 250000
  • 收稿日期:2024-12-18 出版日期:2025-04-15 发布日期:2025-04-21
  • 作者简介:刘健，工程师，硕士研究生，现从事液化石油气脱硫醇和硫磺回收装置工艺技术管理工作。联系电话：18396817796，E-mail: liujian.jnlh@sinopec.com。

Treatment of Alkali Regeneration Tail Gas in Liquefied Petroleum Gas Desulfurization Unit

Liu Jian, Diao Qingguo, Sun Kewen, Wang Peng   

  1. Sinopec Corporation Jinan Branch, Jinan, Shandong 250000
  • Received:2024-12-18 Online:2025-04-15 Published:2025-04-21

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摘要：

某液化石油气脱硫醇装置采用常规的Merox法脱硫醇，碱液再生单元产生的尾气排至低压燃料气系统，存在腐蚀和安全风险。通过对尾气系统进行升级改造，将原净化风改为富氧气气体并进行尾气循环，尾气排放量由80.0 m³/h降至0.8 m³/h，减少液化石油气夹带损失量为144.26 t/a，实现了近零排放的目标。富氧系统取代净化风系统提高了硫醇钠氧化效果，减少消耗碱液30 t/a和催化剂（磺化酞菁钴）0.016 t/a，减少碱渣排放量80 t/a，有效降低了装置运行成本。循环尾气中甲硫醇含量大幅降低，减少了尾气对管道和设备的腐蚀，降低了环境污染风险。尾气循环过程中烃体积分数约为65%，高于其爆炸极限上限，氧体积分数为6%～8%，低于爆炸所需最低需氧量，从根本上避免了尾气系统发生闪爆的可能性，使装置运行达到安全环保的要求。

关键词: 液化石油气脱硫醇, 碱液再生尾气, 富氧气气体, 烃含量, 氧含量, 爆炸极限, 碱渣量, 硫醇硫腐蚀

Abstract:

A liquefied petroleum gas desulfurization unit using the conventional Merox process for desulfurization had tail gas from the alkali regeneration unit discharged to the low-pressure fuel gas system, posing corrosion and safety risks. The tail gas system was upgraded by replacing the original purified air with an oxygen-rich gas and implementing a tail gas recirculation system. The tail gas emission rate was reduced from 80.0 m³/h to 0.8 m³/h, significantly decreasing the loss of liquefied petroleum gas due to entrainment by 144.26 t/a and achieving near-zero emissions. The oxygen-rich system enhanced the oxidation of sodium mercaptide, reducing the consumption of alkali solution by 30 t/a and the catalyst (sulfonated phthalocyanine cobalt) by 0.016 t/a, while decreasing alkali sludge emissions by 80 t/a, effectively lowering the unit's operating costs. The recirculated tail gas had a significantly reduced concentration of methyl mercaptan, mitigating corrosion of pipelines and equipment and reducing the risk of environmental pollution. During tail gas recirculation, the hydrocarbon volume fraction was approximately 65%, above the upper explosion limit, and the oxygen volume fraction was between 6% and 8%, below the minimum oxygen requirement for explosion, fundamentally eliminating the possibility of flash explosions in the tail gas system and ensuring safe and environmentally friendly operation of the unit.

Key words: liquefied petroleum gas desulfurization, alkali regeneration tail gas, oxygen-rich gas, hydrocarbon content, oxygen content, explosion limit, alkali sludge quantity, mercaptan sulfur corrosion