A USGC refinery had been suffering for some time with high levels of organic chlorides in the naphtha feed to the NHT. The chloride level was so high that the available wash water rate was insufficient to avoid severe exchanger fouling and the resulting reactor effluent so corrosive that the piping was holed through resulting in loss of primary containment.
Believing that the source of the organic chlorides was from crude contamination, the client approached Becht to assist them in finding which local crude was the culprit. The team of Becht Process and Corrosion SMEs conducted a holistic and structured RCFA that ultimately determined that the primary source of organic chloride contamination was due to improper PERC disposal that was recycled to the crude unit via the slop oil system.
The practice of disposing PERC was immediately discontinued. In addition, the Becht team provided revised water wash spray design, location, and operation to optimize water wash utilization in the NHT Reactor Effluent system to ensure that corrosion and fouling of the reactor coolers were minimized.
By eliminating the primary source of the organic chlorides and optimizing the NHT Reactor Effluent Water Wash System, Becht eliminated the NHT Reactor Effluent system fouling and corrosion. This not only increased the on-stream time of the unit, but avoid a shutdown of the entire refinery.Contact