Corrosion Inhibition of Sales Gas Transmission Pipelines

摘要

Weight loss methodology was used to study the corrosion-inhibiting effects of 14 inhibitors on carbon steel in a simulated sales gas environment. Two inhibitors passed these tests, showing a corrosion inhibition effectiveness of -90% and preventing pitting attack. Sales gas is normally dried in tri-ethylene glycol (TEG) to lower its water dew point to a level below the lowest expected operating temperature encountered in its transmission through a pipeline.1 Because of this drying process, it is perceived that the gas is "dry" and therefore no water condensation and subsequent internal corrosion are expected.2 Field observations, however, show that even under "dry" sales gas conditions, general internal corrosion is widely encountered, leading to what is known in the industry as black powder.