Sinclair 3HDS Stripping System Module C Level PDF

## Overview: The purpose of the #3 Hydrogen Desulfurization (HDS) Unit is to produce distillate product. This unit uses a blend of light distillate, medium distillate, light cycle oil, light coker gas oil, and mixed gas oils from various locations in the refinery. ### The #3 HDS Stripping System: T...

## Overview: The purpose of the #3 Hydrogen Desulfurization (HDS) Unit is to produce distillate product. This unit uses a blend of light distillate, medium distillate, light cycle oil, light coker gas oil, and mixed gas oils from various locations in the refinery. ### The #3 HDS Stripping System: The #3 HDS Stripping System receives effluent from the Distillate HDS Reactors in the Reaction and Separation System. The primary objective of the #3 HDS Stripping System is to prepare the distillate product for storage. Stripping technology is used to remove light ends, including light distillate and any remaining hydrogen sulfide, from the distillate product stream in order to meet product specifications. The distillate is cooled and dried before it is sent to storage. ### Removing Light Hydrocarbons: The light hydrocarbons that were removed from the distillate product are cooled, condensed, and separated in order to be recovered. Light distillate is provided to the Hydrocracker Unit (HCU) as additional feed to the Main Fractionator. ## The Stripping System: The Stripping System receives the effluent streams from the Distillate HDS Reactors. The purpose of this subsystem is to prepare the distillate product stream for storage to meet product specifications. This is achieved using stripping technology to remove the light ends from the distillate product, and heat exchangers to cool the product before storage. ### The Stripper: The Stripper is a 20-tray stripping column that removes light ends, consisting of light distillate, hydrogen sulfide (H2S), and other light components, from the distillate product stream in order to meet product specifications. ### Stripping Steam: Stripping steam is added near the bottom of the Stripper on flow control. The addition of steam lowers the partial pressure of the hydrocarbon liquids on the Stripper trays. This allows for additional vaporization and separation of more volatile components. This causes all of the hydrogen sulfide to be stripped overhead, along with the light hydrocarbons. ### Stripper Overhead Gas: Stripper overhead gas, consisting of light distillate, H2S, and other light components, rises through the tower. It exits to the Stripper Overhead Condenser (Air Cooler) to be cooled and further separated. ### Distillate Bottoms: Distillate falls to the bottom of the Stripper as stripper bottoms. The product is pumped by the Stripper Bottoms Pumps East/West from the Stripper to the Stripper Feed/Bottoms Exchangers. ### Stripper Feed/Bottoms Exchangers: The Stripper bottoms stream is routed through the tube side of the Stripper Feed/Bottoms Exchangers. It is cooled by stripper feed flowing through the shell side of the exchangers. 13EX-2333/2332 are two heat exchangers in a series of multiple exchangers that are used to cool the hot Stripper bottoms stream before it is sent to storage. ### Stripper Bottoms Air Coolers The cooled Stripper bottoms stream splits and flows through the tubes of the Stripper Bottoms Air Coolers. 13EX-2342/2343 are two air coolers, arranged in parallel, that use ambient air to cool the process stream. The air coolers further cool the distillate stream to the appropriate storage temperature. ### Gas Oil Coalescer: A portion of the cooled distillate from 13EX-2333/2332 can be sent as stripped distillate to the Gas Oil Coalescer in the FCCU Feed System on flow control. ### Stripper Bottoms Cooler: The cooled distillate stream is routed from the air coolers through the shell side of the Stripper Bottoms Cooler. It is cooled by cooling water flowing through the tube side. 13EX-2335 is the last exchanger used to cool the distillate stream before storage. ### Treated Distillate: Treated distillate product exits the shell side of 13EX-2335 on level control. It can be sent to the Coker Charge Tank for storage or to the Diesel Coalescer for water removal. ## Stripper Overhead Subsystem The purpose of the Stripper Overhead Subsystem is to recover as much valuable hydrocarbon product as possible from the Stripper overhead stream. This is achieved by cooling, condensing, and separating the overhead gas using heat exchangers and a separation vessel. ### Stripper Overhead Condenser (Air Cooler): The Stripper (13PV-2303) overhead (OH) gas, consisting of light distillate, hydrogen sulfide (H2S), and other light ends, rises in 13PV-2303 and exits through the top of the tower. It flows through the tubes of the Stripper Overhead Condenser (Air Cooler). 13EX-2340 is an air cooler that uses ambient air to cool the process stream. 13EX-2340 is the first in a series of two heat exchangers that is used to cool and condense the stripper overhead stream so it can be separated in downstream equipment. ### Stripper Overhead Condenser: The cooled and partially condensed overhead stream is routed through the shell side of the Stripper Overhead Condenser and is cooled by cooling water flowing through the tube side. 13EX-2334 is hairpin exchanger used to further cool and condense the overhead stream. ### Stripper Overhead Accumulator: The condensed overhead stream from 13PV-2303 flows into the Stripper Overhead Accumulator. The overhead drum provides the space and residence time for the condensed OH stream to separate into three phases due to the difference in densities: sour gas, hydrocarbon liquid, and sour water. ### Sour Gas: Sour gas, containing the separated hydrogen sulfide, is routed to the HDS Stripper Contactor in the ARU 1 Gas Contacting System, on pressure control. ### Recovered Light Distillate: The recovered light distillate liquid is pumped by the Stripper Overhead Pumps East/West from the bottom of 13PV-2319 to the Fractionator Feed/Effluent Exchanger in the Hydrocracker Unit (HCU) on level control. In the HCU, the light distillate is heated and used as additional feed for the Main Fractionator. ### Sour water: Sour water collects in the boot of the Stripper Overhead Accumulator. It is routed from the overhead accumulator to the Effluent Condenser in the #3 HDS Reaction and Separation System as wash water. Sour water can be routed to the SWS Collection Drum to be recovered. This is used any time both of the Water Wash Injection Pumps are offline to prevent sending the sour water to another unit. ### H2S Scavenger: If needed, hydrogen sulfide scavenger can be injected into the hydrocarbon stream exiting 13PV-2319, by the H2S Scavenger Pump. Hydrogen sulfide scavenger is an additive that can be used to react with and remove any hazardous hydrogen sulfide present in the light distillate stream. ### Off-spec light distillate: Off-spec light distillate can be sent to the Tank Farm Slop Oil Header. ## Condensate Subsystem The Condensate Pot receives condensate from the Condensate Header and the Stripper Feed Preheater. It also receives boiler feed water (BFW) from the Boiler House, on level control. 13PV-2315 is a two-phase separation vessel. The condensate undergoes a pressure reduction in the vessel, which causes part of the liquid to flash into 50 psig steam. It is also used to store condensate for use downstream as wash water. ### 50 psig Steam: 50 psig steam can exit the top of the Condensate Pot to the 50 psig Steam Header. The steam rises inside the condensate pot and flows through a demister pad, which prevents any of the condensate from exiting with the steam. If needed, 50 psig steam can also be sent from the header to the Condensate Pot. ### Condensate Pumps: Condensate is pumped by the Condensate Pumps East/West from the bottom of the Condensate Pot to multiple locations including the Condensate Header on level control. It can also be sent to the Particulate Filter After Carbon Bed in the #3 HDS Absorption System. ### Wash Water: A portion of the condensate pumped by the Condensate Pumps can be injected into the Stripper overhead stream on flow control. Condensate is used as wash water to reduce corrosion and prevent the buildup of solid deposits in downstream equipment. ### Stripper Overhead Accumulator: A portion of the condensate can be sent into the water boot of the Stripper Overhead Accumulator on level control. Condensate can be used in the Accumulator as make-up. ## Distillate Drying Subsystem The Distillate Drying Subsystem uses a coalescer and salt tower to remove water from the distillate product before it is sent to storage. ### Diesel Coalescer: Treated medium distillate enters the subsystem from the Stripper Bottoms Cooler. It is mixed with #2 HDS Stripper bottoms from the #2 HDS Stripper Bottoms Trim Cooler. The combined #2 and #3 HDS Stripper bottoms stream is routed to the Diesel Coalescer. The Diesel Coalescer uses internal filter elements to remove the liquid water phase, present in the stripper bottoms stream, before the stream is sent to storage. ### Diesel Product Trim Cooler: Diesel from the Diesel Product Trim Cooler in the HCU Distillate Fractionation System is also mixed with the stripper bottoms stream, upstream of 13PV-2320, for water removal. A portion of the diesel can be routed to the Diesel Salt Towers. ### Naphtha Splitter Bottoms Air Cooler: A portion of the Diesel Coalescer feed stream, containing #2 HDS Stripper Bottoms and/or #3 HDS Stripper bottoms, can be routed to the Naphtha Splitter Bottoms Air Cooler in the LEF and Naphtha Splitting System to be cooled before it is sent to the coalescer. ### Returned Stripper Bottoms: The cooled #2 HDS/#3 HDS Stripper bottoms can be returned from 5EX-1685 to the Diesel Coalescer for water removal. ### Separated Water: The separated water collects in the boot of the Diesel Coalescer and is drained off on level control. ### Distillate Dryer Salt Tower: The distillate product stream exits the coalescer and is routed to the Distillate Dryer Salt Tower. The Distillate Dryer Salt Tower is equipped with an internal salt bed and gravel bed to remove any remaining free water and some dissolved water from the distillate product before it is sent to storage. ### Water Separation: Inside the Distillate Dryer Salt Tower, water separates from the distillate product. It collects in the bottom of the Distillate Dryer Salt Tower and is drained off. ### Dried Diesel Product: The dried diesel product is routed from the top of the salt tower to the Jet/Kero Salt Dryer for additional water removal. ### Water Removal: Water is removed from the distillate product stream by the Distillate Drying Subsystem using a coalescer and a salt tower to remove water from the distillate product before it is sent to storage. ### Stripping: Stripping is a process that removes light ends, including light distillate and any remaining hydrogen sulfide, from the distillate product stream in order to meet product specifications. It is used to prepare the distillate product for storage. ### Stripping Technology: Stripping technology is used to remove the light ends from the distillate product. This is achieved using stripping technology to remove the light ends from the distillate product, and heat exchangers to cool the product before storage.