Contact angle and corrosion of a Water – CO2 system on X70 and S41500 at 278 K and pressures up to 20 MPa

Autor: P. Jaeger, Ralph Baessler, Sandra Knauer, Le Quynh-Hoa
Rok vydání: 2019
Předmět:
Zdroj: International Journal of Greenhouse Gas Control. 89:33-39
ISSN: 1750-5836
DOI: 10.1016/j.ijggc.2019.06.021
Popis: Interfacial properties related to wettability and corrosion in CO2 transport pipelines are experimentally determined by the sessile and the pendant drop methods. The contact angle of a water drop in a compressed CO2 atmosphere is analyzed on an X70 pipeline carbon steel and compared to that on a martensitic steel S41500 to elucidate the effect of corrosion process on active wetting behaviour. The measurements are performed with liquid CO2 at 278 K and pressures ranging from 5 to 20 MPa. The results show that the contact angle (CA) increases with pressure from 132° to 143° for S41500 and from 117° to 137° for X70 and decreases with drop age by 20° to 24° regardless of the pressure and of the fact that corrosion only occurs on X70, which is confirmed by scanning electron microscopy, element mapping and energy dispersive x-ray spectrometry (EDS) analysis. At higher pressure, the contact angles on both materials converge. Further, related properties like density and interfacial tension (IFT) were determined. CO2 - saturated water has a higher density than pure water: At 5 MPa saturated water reaches a density of 1017 k g ⋅ m - 3 and at 20 MPa 1026 k g ⋅ m - 3 compared to pure water with a density of 1002 k g ⋅ m - 3 and 1009 k g ⋅ m - 3 , respectively. In this pressure range the IFT drops from 33 m N ⋅ m - 1 at 5 MPa to 23 m N ⋅ m - 1 at 20 MPa.
Databáze: OpenAIRE