Question
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At one of our gas processing plants, we are using hybrid amine solution MDEA for acid gas recovery. H2S 3% and CO2 1%. Our filter replacement frequency is very high, observed corrosion, sample analysis reflects, Iron count 14ppm. Other results are high acetates 13000 ppm in amine, PH reducing trend ...HSAS 1.5%. There is no any chemical injected on wellsite. What could be cause of corrosion /filter change out? What could be other source for acetates as production chemicals are not used on wellsite?
Mar-2022
Answers
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Salem Ghoul, Mellitah O&G Co, smghoul@gmail.com
Check the O2 at MDEA system may be the MDEA Tank not blanketed, or water (DEMI) used for preparation MDEA Sol is oxygenated.
Jan-2023
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Michael Clements, FTC, mclements@ftc-houston.com
Did the filter usage increase coincide with the change to the hybrid amine solution? Were there any other changes in the process prior to the increase in filter usage? What are your TSS, PSD and hydrocarbon content prior to the filtration and what retention, efficiency and flx rate are you at? Utilizing the information here, I would suspect that corrosion particles are being freed by the fluid and are being captured be the filters. However, to conclusively determine the root cause, more data is required.
Mar-2022
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Lorenzo Micucci, Siirtec Nigi, l.micucci@siirtecnigi.com
Acetates, along with glycine and other organic acids, are degradation products of alkanolamines reactions with oxygen. Therefore, their presence in the solvent circuit is a clue of oxygen presence in the acid gas recovery feed. Moreover, oxygen can degradate MDEA to bicine, an amino-acid which is regarded by many as particularly corrosive. This can explain the observed corrosion. In conclusion, the root cause of the reported problems may be attributed to the oxygen contamination of the treated gas.
Mar-2022
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Nathan Hatcher, Optimized Gas Treating, Inc., nate.hatcher@ogtrt.com
Oxygen ingress leading to oxidative degradation of the amine is one explanation. If the feed contains cracked gases from a Coker or FCC, then cyanide in the feed can lead to the formation of carboxylic acids by hydrolysis.
Mar-2022
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