In Our Sour Water Stripper Unit, The quality of Stripped Water is as follows:
H2S :0.4 PPM(Max.10 PPM)
NH3: 2.4 PPM (Max 50 PPM)
The H2S and NH3 are in desirable range but still we couldn't get lower Ph in stripped water? Is any other factor causing low Ph?
NS Murthy, Suez, email@example.com
Not clear on the question. If I understand that you are getting a pH of 8.9 in the stripped sour water and you want to know the reason. High pH can be either from NaOH being injected in SWS unit to strip off NH3 or from amines from upstream units getting ingress into sour water. Look into the following.
1. Types of amines used in steam generation units.
2. Potential ingress of amines (MEA, DEA or MDEA) used in amines system which at times purge amines from Amine regeneration unit OH receiver boot water.
3. Refiners do add neutralizing amines in OH of CDU / VDU. Any excess could end up in raising the pH.
4. One can expect amines in the sour water from Coker.
5. Last but not the least, look for tramp amines (as mostly seen by pH raise across desalters) in Crude.
Krishna Rao Pulugurti, Retired/Consultant, firstname.lastname@example.org
Please check for chloride. It appears the water contains chloride in the form of hydrochloric acid. You have to maintain the pH of de-salter water above 7. Magnesium chloride hydrolises giving hydrochloric acid which lowers the pH. This could be one reason.