Session: OAC-06-02 Continued Safe Operation of Existing Assets-2

Paper Number: 123081

123081 - Assessing a Hydroprocessing Reactor After a High Temperature Excursion 

A thick cold wall conventional 2.25Cr 1Mo with 347SS weld overlay and internal insulating refractory was affected during an external high temperature excursion. The reactor is part of a two-train unit with each train including an oil feed heater, a hydrogen feed heater, two reactors with ebullating bed pumps, three high pressure separators, and associated effluent coolers.  Reactor internal normal operating condition is 795-825°F and 2,700-3.100 psig. A comprehensive metallurgical, non-destructive and fitness for service per API 579-1/ASME FFS-1 assessment was completed before deciding to place the reactor in service. MTI publication “DAMAGE ASSESSMENT INVESTIGATING FIRES, EXPLOSIONS AND STORM DAMAGE IN CHEMICAL PLANTS” was used as guidance as well. The fitness for service assessments included shell out-of-roundness, leaning and distortion and local thin areas as consequence of scoop samples removal. An integrated computational materials engineering (ICME) approach was taken as part of the approach to assess the future-service capabilities of a thick-walled steel pressure vessel that was damaged by overheating. Removal of scoop samples allowed for metallurgical characterization and mechanical property assessment. No repair was needed at the scoop sample locations. Indications of weld overlay disbonding were not reported. The different assessments supported the decision to place back the reactor in service with complementary monitoring plans.  The reactor has been now in service over two years.

Keywords: Reactor, Excursion, Hydrocracker

Presenting Author: Jorge Penso Shell Projects and Technology

Presenting Author Biography: Principal Inspection and Integrity Engineer

Authors:

Kevin Batts Shell - Geismar Plant
Jorge Penso Shell Projects and Technology
Jorge Hau Shell Global Solutions (US) Inc.
Mitul Dalal Shell Global Solutions (US) Inc.