天然气低温处理过程中汞的分布与防治

Distribution and prevention and control of mercury during the low temperature treatment process of natural gas

关键词:  天然气  低温处理  汞  分布  防治

Key words:  natural gas  low temperature treatment  mercury  distribution  prevention and control

摘要:

汞在天然气低温处理过程中很容易以液态的形式析出,给天然气生产带来潜在的安全隐患,一旦进入长输管道,还可能造成下游的污染。针对低温处理工艺对汞的脱除作用、天然气低温处理过程中汞的流向及防治方法等进行了研究。研究结果表明,低温处理工艺对汞具有很强的脱除作用,天然气中大部分汞在低温处理过程中以液态汞的形式析出,少部分进入外输气。为消除汞对下游的污染,天然气脱汞可采取干气脱汞或湿气脱汞两种方法,干气脱汞的优点是脱汞剂的性能可以得到很好的保障,脱汞剂用量少,缺点是天然气低温处理过程中存在汞的析出问题,给检修作业带来困难。湿气脱汞的优点是可有效降低汞的析出问题,缺点是脱汞剂用量大,用户可根据自身生产情况进行合理的选择。 

Abstract:

During the process of low temperature treatment, the natural gas containing mercury is easy to separate out in the form of liquid mercury, which will bring potential safety hazards to natural gas production. In addition, once the natural gas containing mercury enters the long-distance pipeline, it may also bring potential safety hazards to downstream users. The effects of low-temperature treatment process on mercury removal, the flow direction of mercury during the process of natural gas low-temperature treatment and the prevention and control methods were studied. The results showed that the low temperature treatment process had a strong removal effect on mercury. Most of the mercury in natural gas was separated out in the form of liquid mercury during the low temperature treatment process, and a small part entered into the external transportation gas. In order to eliminate the pollution of mercury to downstream, dry gas or wet gas mercury removal methods could be adopted to remove mercury from natural gas. The advantages of dry gas mercury removal method are that the performance of mercury adsorbent can be well guaranteed and the amount of the mercury adsorbent is small, and its disadvantage is that mercury precipitation exists during the process of low temperature treatment of natural gas, which will bring difficulties to maintenance. The advantage of wet gas mercury removal method is that it can effectively reduce mercury precipitation, and its disadvantage is that the amount of the mercury adsorbent is large. Users could make a reasonable choice according to their own production conditions.