Corrosion Failures in Atmospheric Residue Desulfurizer Unit after the Revamp (ARDS)

Corrosion Failures in Atmospheric Residue-Desulphurizer Unit after the Revamp

 

 Muased Al Arada

 Mutlaq M. AL-Enezi

 Sunil V. Vipat

 Anil Kumar Ray

 Kuwait National Petroleum Company

 Mina Abdulla Refinery

 P.O.Box-69, Safat, Kuwait-13001

 E-mail: s.vipat@knpc.com

 Abstract:

 

 

 Atmospheric Residue De-sulphurizer Unit in one of the refinery was revamped in year 2004 with a new online catalyst replacement technology process for increasing the operating run length as well as capacity of the unit.

This paper describes three corrosion case studies which were direct result of the revamp of the unit and lack of thorough understanding of the corrosion mechanisms / degradations, expected due to process / capacity changes at design stage.

The first case history is an exchanger tube sheet and components corrosion due to high temperature sulfidation. The second case study is about erosion of inlet nozzle pipe and bulging / thinning of the impingement plate in the high pressure cold separator vessel (HPCS Vessel). Third case study is about high temperature corrosion of piping including connected diesel stripper tower liquid inlet nozzle due to changes in operating temperature and fluid resulting in high corrosion rates.

Based on these case studies thorough re-evaluation of the whole unit has been under taken using RBI methodology and is expected to result in revised inspection plans and intervals.

 Keywords

 

 Erosion, corrosion, velocity, high temperature sulfidation, fouling, thinning, bulging, impingement