杂质对三甘醇脱水能力的影响研究

Influence of contaminants on TEG dehydration performance

天然气净化装置脱水三甘醇溶液在长期使用过程中,易受到污染,从而降低三甘醇脱水能力,影响正常生产。本文通过随机抽样检测,确定三甘醇中杂质种类与含量,明确研究目标。自主设计、搭建一套模拟现场脱水装置运行状况的实验装置,高压下以携水氮气模拟湿天然气,研究各杂质对三甘醇脱水能力的影响。并通过正交实验考察各杂质之间的交互关系,得到影响三甘醇脱水能力的显著因素。结果表明,热稳定性盐中的Mg^(2+)、Ca^(2+)、Fe^(3+)、K^+,有机杂质中的甲基二乙醇胺(MDEA)、甲醇,固体悬浮物中的FeS对三甘醇脱水能力影响显著。Mg^(2+)、MDEA以及Mg^(2+)与MDEA的交互作用严重抑制三甘醇的脱水能力,在现场生产中应重点监测,保证脱水装置正常运行。

In natural gas processing plants, the triethylene glycol（TEG） for dehydration could be contaminated during long-term use, which would decrease its dehydration ability and affect the normal production. This paper adopted random samples to determine the species and contents of contaminants in TEG and make clear the research objects. The effects of various contaminants on the dehydration ability of TEG were investigated in a self-designed experimental installation for simulating the field operation by using the water-containing nitrogen as the simulated wet natural gas under high pressure. Furthermore, the interactive relationship of contaminants was investigated by orthogonal test to get several significant factors. The results showed that the Mg^（2＋）, Ca^（2＋）, Fe^（3＋）and K^＋ heat-stability salts, the organic contaminants methyldiethanolamine（MDEA） and methanol and the Fe S suspended solids all had a significant effect on the dehydration performance of TEG. Mg^（2＋）and MDEA and their interaction seriously inhibited the dehydration ability of TEG, which should be closely monitored to ensure the normal run of dehydration unit.