Checking H2S corrosion pipe 2

[LuizSouza]

Hi Fellows,

How can I be sure that H2S is the source of corrosion os upper side of a gas pipeline, we assume 5 ppm contents in our gas production.

 

[YLWEA]

we have successfully used XRD (x-ray diffraction) of corrosion products as an indicator of the most likely corrodents. The corrosion product identification is best used in conjunction with electrochemical potential-pH charts since the compounds are not always obvious indicators of the specific corrodent (i.e., the presence of an oxide does not always mean O2 was responsible).

 

[LuizSouza]

YLWEA,
Thank you very much. But you coud be a little bit more specific concernig to RXD.

 

[YLWEA]

XRD analysis can be performed by many chem analysis labs. It is useful because instead of merely determining the chemical composition, it determines the crystalline form of the corrosion product. It can differentiate among various types of oxides, carbonates, and sulfides, for example, rather than just reporting the amounts of iron, sulfur, oxygen, etc. that might be present. Various references and technical papers have discussed how various corrosion products can be indicators of specific corrodents or environmental conditions responsible for the corrosion. Note that sometimes the corrosion products are insufficiently crystalline to be analyzed by XRD.

 

[grampi1]

HCl test will tell you if scale if FeS variant and is much faster and less expensive. Won't tell you the crustal structure of the FeS. XRD will tell you if the scale is carbonate rather than FeS.