AM-00-19 IMPROVED REACTOR INTERNALS FOR SYNCRUDE’S HGO HYDROTREATERS

Description:

Current operation of hydroprocessing units in many refineries differs significantly from the original design. As a result existing reactor internals may no longer be capable of providing adequate vapor/liquid distribution, quench mixing or redistribution. New state-of-the-art reactor internals are designed to minimize radial temperature spread, hot-spots, and bypassing caused by poor distribution, and should be considered when revamping units for higher severity operations. Maximum catalyst utilization with zero bypassing will be essential in order to meet potential future ultra-low sulfur fuels specifications. This paper describes how Syncrude Canada Ltd. successfully improved distribution problems in the catalyst beds of the HGO hydrotreating units at the Mildred Lake Upgrader. Since the original start-up in 1978, Syncrude has steadily increased the unit throughput to accommodate expansion of the Upgrader. However, recent operations were hampered by measured radial temperature differences up to 40oC in some catalyst beds. Syncrude evaluated new reactor internals designs offered by various licensors and engineering companies, and ultimately selected Topsoe to provide Vapor-Lift distribution trays and Vortex mixing chambers to de-bottleneck their HGO reactors. Syncrude also closely planned and coordinated the execution phase of the project to ensure that removal and replacement of the catalyst and internals was accomplished within the short time frame allowed by the turnaround schedule. Subsequent to installation of the Topsoe high performance reactor internals, radial temperature spreads have been reduced to less than 1-2oC, which has enabled Syncrude to confidently increase the unit throughput by approximately 10% above their previous limitation, while still meeting all processing objectives.