Abstract: Affected by raw materials and operating conditions, the catalyst replacement cycle of fixed bed residue hydrogenation unit is normally 1-2 years, which cannot match the maintenance cycle of 3-4 years for refineries. During the startup and shutdown of a single train residue hydrogenation unit for catalyst replacement, some gas-containing oils are sent to the tank farm, causing environmental pollution and safety risks. To solve this problem, the equipment selection, investment and energy consumption of two degassing processes were compared with each other based on simulation analysis, and some suggestions were put forward for the selection of process.

Key words: residue hydrogenation, oil drainage, start-up and shutdown, degassing