Effects of heat-stable salts on the corrosion behaviours of 20 steel in the MDEA/H₂S/CO₂ environment

Abstract

The effects of HSS (heat-stable salts) on the corrosion behaviours of 20 steel were explored using selfdesigned HTHP autoclave. The charateristics of corrosion scales were investigated by SEM, EDS and XRD. Corrosion scales of 20 steel formed in the liquid phase environment were mainly composed of FeS 2 , Fe 3 O 4 , and Fe. HSSs affected the corrosion rate through changing the morphology of corrosion scales of 20 steel. Inorganic salts enhanced the attractive force between ions and the hydrolysis of CH 3 COO − in organic salts promoted the ionisation of HS − , which accelerated the deposition of FeS on the surface of 20 steel to form a dense corrosion scales, thereby significantly reducing the corrosion rate of 20 steel. Inorganic-organic salts reduced the bonding opportunity between Fe 2+ and S 2− and allowed the formation of porous corrosion scales on the surface of 20 steel, thus increasing the corrosion rate of 20 steel.

Corrosion behavior of carbon steel in H2S-CO2-H2O-methyldiethanolamine (MDEA) solution under the presence of chloride ions

“…The XRD results of corrosion products provided by the literature (Zhu et al , 2015; Dong et al , 2019) were FeS 2 /FeCO 3 /FeS/Fe 3 O 4 , and the XPS results of this paper in Figure 15–16 were inferred that corrosion products were FeS/FeO/Fe 3 O 4 when the test temperature is 60°C and 140°C. The increase of chloride ions reduce the acid gas load so that without FeCO 3 in the product, and the corrosion rate shows different change rules by different content of Fe 3 O 4 .…”

“…HS - and HCO 3 - ions are further decomposed into form S 2- , CO 3 2- and H + [as shown in equations (4) and (5)]. The formation process of corrosion products can be explained in equations (6) – (8) (Dong et al , 2019): …”

Removal of Heat‐Stable Salts from Lean Amine of a Gas Refinery via Electrodialysis

“…An increase of the HSS concentration in the amine solution causes different problems during gas sweetening: a reduction in the CO 2 absorption capacity, equipment corrosion, and foaming [3,4]. To overcome these problems, various technologies such as neutralization of amine with sodium hydroxide [5,6], solvent extraction [7], ion exchange bedding [8,9], replacement of amine with fresh amine [10], distillation [11], electrosorption (using electromagnetic forces) [12], capacitive deionization (CDI) [13], and membrane technology [14][15][16][17] have been applied to reduce the HSS concentration in gas refineries.…”

Determination of critical salinity of pitting and uniform corrosion of X60 under CO2-O2coexistence environment

“…Previous research studies have been focusing on the effects of high salinity produced water on steel under CO 2 corrosion (Liu et al , 2016; Dong et al , 2019a; Dong et al , 2019b; Zhang et al , 2012). Cui et al (2006) point out that the (Fe, Ca)CO 3 is formed on the corroded surface at low temperatures.…”