某天然气处理厂处理装置汞污染控制研究

Study on mercury pollution control in a natural gas treatment plant

关键词:  汞防护  天然气处理  VMGSim  汞分布  乙二醇

Key words:  mercury protection  natural gas treatment  VMGSim  mercury distribution  ethylene glycol

摘要:

天然气在处理厂处理过程中,汞会进入各工艺物流单元,汞不仅会挥发到环境中危害工作人员健康,还会对生产设备造成汞腐蚀及贵金属中毒等。通过VMGSim模拟软件对整个天然气处理厂加工处理工艺单元进行模拟分析,发现天然气中汞主要进入乙二醇富液、再生塔塔顶污水及稳定凝析油中,这对后续处理厂进行汞污染控制具有指导性意义。通过对原料气组成、低温分离器进料温度及乙二醇含量进行特性分析,发现原料气中轻烃组分的增加有利于乙二醇对汞的吸收,降低乙二醇质量分数可以促进乙二醇富液对汞的解吸。从环保、安全的角度出发,提出了整套天然气处理装置中主要物流单元汞污染防控措施。 

Abstract:

Mercury will enter into each process mass flow unit during natural gas treatment. Mercury would not only be volatile to the environment and harm to the health of the staff, but also cause mercury corrosion and noble metal catalyst poisoning in the production equipments. In this paper, VMGSim simulation software was used to simulate and analyze the whole natural gas processing and it was found that mercury in natural gas mainly entered into ethylene glycol rich solution, wastewater from the top of regeneration tower, and stable condensate oil, which had guiding significance for mercury pollution control in subsequent treatment plant. Through analyzing the composition of feed gas, feed temperature of cryogenic separator, and the content of ethylene glycol, it was found that the increase of light hydrocarbon in feed gas was beneficial to the absorption of mercury by ethylene glycol, and the decrease of the mass fraction of ethylene glycol would promote the desorption of mercury by ethylene glycol rich liquid. From the perspective of environmental protection and safety, the prevention and control measures of mercury pollution in the main units of the whole natural gas processing plant were put forward.