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If caustic dosing suspended due to some unavoidable reasons is it possible to reduce overhead corrosion (caused by hydrochloric acid) by increasing amount of neutralizer like ammonia or amine at overhead of the Atmospheric distillation unit?
 
Answers
04/10/2012 A: David Engel, Nexo Solutions, david.engel@nexosolutions.com
Please be very careful. The product of the neutralization is a salt. The enhanced salt concentration can provide a highly corrosive environment when contacted with water. Please verify with your additive vendor first. We can also assist by providing technical support and engineering. We work with perhaps the most effective and knowledgeable corrosion specialist. Do not hesitate to contact us should you need support. We are are a process efficiency company and our interest is offering solutions and solve problems.
26/09/2012 A: Berthold Otzisk, Kurita Europe GmbH, Berthold.Otzisk@kurita-water.com
The injection of caustic after desalting is a very effective way to significantly reduce the chloride concentration in the overhead system. Many refineries don´t use casutic, because it bears some risks for downstream operations (i.e. catalyst poison).
A powerful corrosion protection program with neutralizing amine and filming amine will provide perfect results. Ammonia is not a good choice to neutralize acidic components like HCl. Being very volatile it will start neutralization relatively late at the end of the condensation process with a high risk of salt fouling. A modern neutralizing amine will quickly shift the low pH to a save level.
17/09/2012 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
Yes. Approximately one-half of the world's refineries use the caustic method. The rest rely on other methods such as you listed.