A pilot reactor study to determine operational factors of the commercial hydrodesulphurization (HDS) catalyst to produce ultra-low sulphur diesel (ULSD)

• An ULSD production testing on pilot plant and applying it for industrial hydrodesulphurization process.
• Experimental data from pilot plant test to calculate hydrogen consumption & estimate catalyst deactivation rate.
• Study the impact of change in feed & process conditions on the performance of commercial unit to produce ULSD.

A pilot plant test was carried out using a catalyst from the refinery hydrotreater unit to process blend feed of 70 vol% Light Gas Oil – LGO & 30 vol% hydrotreated Gas Oil – HDT GO to produce 8 ppm ultra-low sulphur diesel (ULSD) product. The impact of changes in process conditions have been studied for catalyst deactivation rate and hydrogen consumption. Test results shown that refinery unit can process such blend feed to reach 8 ppm sulphur product by an increase of the reactor bed temperature. However due to higher aromatic content in the blend feed as compare to reference feed LGO, moderate increase in hydrogen consumption was also observed. Catalyst performance was evaluated at 55/42/32 bar hydrogen partial pressure (PPH2) to determine catalyst deactivation rate and hydrogen consumption, targeting ULSD product. A decrease of PPH2 from 52 bar (which is current operating condition) to 32 bar resulted in reduction of H2 consumption but also shows decrease of catalyst cycle length due to higher deactivation rate. Pilot plant test shows that by contriving computational methods and analysis techniques for hydrogen balance & catalyst deactivation rate from the pilot plant test data, it becomes possible to predict catalyst performance in commercial unit.