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Do anyboby experience fouling in the preheat trains while processing Doba crude in CDU/VDU?
I heard that doba crude by nature is a solvency crude which won't foul the exchangers. Is it true?
Now we process the Doba crude with minimum of 4% and we want to increase the percentage.
What are the constraints while processing Doba and what pecentage can be added with some allowable constraints in hand?
 
Answers
02/07/2013 A: Krishna Rao Pulugurti, Retired/Consultant, pkrao2012@yahoo.com
Doba crude contains high amounts of calcium as naphthenates which form stable emulsuins and foul refinery systems. Many additives are available in market to remove calcium from this type of crudes. Nalco, Dorf Ketal, Baker Petrolite are a few companies offering additives for removing calcium from this type of crudes.
08/01/2010 A: Eric Vetters, ProCorr Consulting Services, ewvetters@yahoo.com
One of our facilities that processed Doba saw some fouling. The problem was linked to desalting problems and additives used to control the high Calcium levels in the crude. The desalters were undersized for processing a crude as heavy as Doba and the resulting water carryover took the calcium removal additives into the hot preheat train with the water, resulting in severe fouling.