工艺参数对MDEA脱硫装置安全平稳运行的影响分析

Influence analysis of process parameters on safe and steady operation of MDEA desulfurization unit

关键词:  工艺参数  MDEA  溶液  腐蚀  发泡

摘要:

川渝气田某高含硫天然气净化厂采用MDEA脱硫工艺,装置在日常生产运行过程中出现了较为严重的腐蚀及拦液发泡问题,多次停车。为明确原因,结合装置检修期间发现的具体问题,对运行期间的溶液质量、酸气负荷、溶液循环量、流速、温度等关键参数进行了分析。结果 表明:①部分管线局部流速超过30 m/s；②酸气负荷长期超过设计值0.6 mol/mol；③重沸器及再生塔底部温度超过127 ℃；④MDEA溶液中产生大量热稳定盐及颗粒物。在此基础上,进一步阐述了不同工艺参数间存在的相互关系及其对装置平稳运行的影响。建议在今后的生产运行过程中,加强脱硫装置工艺参数的综合管理,确保实际运行符合设计要求。 

Abstract:

MDEA desulfurization process was adopted in a high sulfur natural gas purification plant in Sichuan and Chongqing gas field. Serious corrosion and liquid blocking foaming problems occurred in the daily production and operation of the plant, which eventually led to the shutdown of the unit. In order to clarify the reason, the key parameters such as solution quality, acid gas load, circulation rate of the solution, flow rate and temperature during operation were analyzed in combination with the specific problems found during overhaul of the plant. The results showed as follows:(1) the local velocity of some pipelines exceeded 30 m/s; (2) the acid gas load exceeded the design value 0.6 mol/mol for a long time; (3) the bottom temperature of reboiler and regeneration tower exceeded 127 ℃; (4) a large amount of thermal stable salts and particles were generated in MDEA solution. On this basis, the interrelation between different process parameters and influence on the stable running of the device were further expounded. In the future production and operation process, it was suggested that the comprehensive management of process parameters of desulfurization unit should be strengthened to ensure the actual operation meeting the design requirements.