Q & A > Question Details
Why does PH increase in effluent water from electrical desalters? And what is the reason for monitoring such PH levels?
15/12/2017 A: Sridhar Balakrishnan, Bharat Oman Refineries Limited , laksrid@yahoo.com
Wash water, which is source from sour stripped water, contains caustic. Caustic is added in some of the refineries to improve stripping efficiency in sour water stripping unit.
14/12/2017 A: Eric Vetters, ProCorr Consulting Services, ewvetters@yahoo.com
The change in pH across the desalter gives an indication as to the quantity and types of contaminants in the crude oil. Some crudes have organic acids and cause a drop in pH across the desalter. Other crudes or slop streams can contain tramp amines. If these amines are not all removed in the desalter, they can form very corrosive amine hydrochloride salts in the crude tower. Monitoring the pH change across the desalter can give a quick indication of when these kinds of compounds might be present.
Also high pH in the desalter can lead to emulsion problems and an increase in the size of the rag layer. Basic compounds can react with naphthenic acids in the crude to form soap molecules that get stuck at the oil/water interface.