Shutdowns
Generally the first step of a hydrotreater shutdown
What is pull feed
Before starting up a unit, this must be removed from all equipment to avoid fires and explosions
What is oxygen
The required safety system on a hydrocracker or dewaxing unit to take action on high reactor temperatures
What is an auto-depressuring system
This molecule is found in almost all renewable feedstocks
What is triglyceride
True/False: Hydrocracking is the most difficult reaction to happen in a hydroprocessing unit
True
CO is measured in the makeup and recycle gas to prevent formation of the toxic compound
What is nickel carbonyl
This test done is on equipment during a startup to make sure it is tight
What is a leak test
The recommended action when a significant loss of containment occurs in a unit
What is emergency depressuring
These contaminants are frequently found in renewable feedstocks
What are metals
This feed contaminant must be removed below 30 ppm for hydrocracking to occur
What is nitrogen
This gas is circulated through the reactor to remove oil from the catalyst
What is hydrogen
This process is used to change the environment in equipment from N2 to H2
What are pressure/depressure cycles
The recommended action when recycle hydrogen flow is lost to the reactor
What is emergency depressuring
Removal of this element causes the formation of water and a large heat release
What is oxygen
The term used to define the amount of hydrocracking that occurs
What is conversion
The pressure that is optimal for hot stripping the catalyst
What is the highest possible pressure
This is the maximum temperature allowed for low temperature sulfiding prior to breakthrough
What is 500F
The initial emergency action that should be used to stop a temperature excursion from turning into a runaway
What is cutting back on makeup hydrogen so the pressure slumps
This process converts normal paraffins to isoparaffins
What is dewaxing
This characteristic is the single most important factor when choosing a hydrocracking catalyst
What is yield
The recommended length of time required for a hot strip of the catalyst
What is the longer of: 8 hours or 2 hours after oil stops appearing in the separator
The amount of H2S in the recycle gas that signifies breakthrough
What is 5000 ppm or 0.5%
What action must occur if all flow is lost through a furnace tube
What is chopping furnace fires
This calculation is used to judge the CO2 pollution impact of renewable diesel
What is carbon intensity
This compound is sometimes added to hydrocracking catalyst before startup to "numb" it
What is ammonia or amine