Debottlenecking Hydrotreaters

 

Hydrotreaters also can be debottlecked. Higher capacity catalyst, activated support balls, dense loading of the reactor can all increase the reactor capacity. Once a unit is built, it often is most profitable to maximize the throughput up to the charge pump hydraulic limits. Oftentimes, the charge pump spare can be turned on to increase the oil charge flow. Larger control valves may reduce the charge circuit pressure drop.

There is usually an incentive to run hydrotreaters at the highest possible pressure up to the equipment design pressures. There must be an acceptable safety margin between the operating pressure and the relief valve set pressure to handle the minor unit pressure swings so that the relief valves do not lift. Furthermore, if conventional relief valves are installed, the operating pressure must be maintained below approximately 90% of the relief valve set pressure so that the relief valves do not leak. Pilot operated relief valves allow operation up to 95% of the relief valve set pressure.