Abstract
Triazine-based hydrogen sulfide (H2S) scavengers are the most commonly used additives in the oil and gas industry. One of the reaction products of the scavenging process is an organic amine. The organic amine by-product, together with amines in slop oil and the desalter wash water, are collectively referred to as "tramp amines." The most-common tramp amines from the H2S scavenging process are mono-ethanolamine (MEA) and methylamine (MA). These tramp amines have the potential to react with hydrochloric acid (HCl) to form corrosive amine hydrochloride salts in the crude atmospheric distillation tower and overhead. Among these tramp amines, MEA has the highest potential of forming corrosive salts. To date, continuous monitoring for tramp amines has been limited to the bulk aqueous phase (sour water, brine, etc.) using ion chromatography (IC). This limitation not only presents a challenge with respect to turn-around time, it also prevents the refiner from taking proactive measures to mitigate amine hydrochloride salt deposition.
This paper presents a field methodology for detection and quantification of MEA in the raw crude. Detection and quantification is achieved via the use of a field-deployable analyzer that uses field asymmetric ion mobility spectrometry (FAIMS). This approach enables quantification of MEA down to 1 ppm in crude oil. The combination of this fast, on-site quantification of MEA with ionic modeling enables the refiner to take timely corrective actions to mitigate MEA hydrochloride salt deposition.
