FCCU Main Fractionator (This tower is also known as FCC Fractionator, or FCC main column.)
The main purpose of this column is to cool down and separate the mixture of hydrocarbons coming from the FCC reactor overhead line into manageable fractions that can be treated in processes downstream or used as blending products. The tower does not need external heating equipment (reboiler or furnace) to provide energy for the separation to be carried out; all the energy is provided by the inlet stream. Moreover, several pumparounds are usually needed to achieve an adequate temperature profile inside the tower. Heat can be recovered from the pumparounds for preheating other streams (usually as part of the feedstock preheating train in the FCC unit) or for generating steam to be used elsewhere.
The most common products obtained from an FCC Fractionator are: dry gas (hydrogen + methane + hydrogen sulphide + ethane + ethylene + inerts), propane + propylene (PP), butanes + butylenes (BB), naphtha (usually from C5’s to FBP up to 400°F or 204°C), light cycle oil (LCO, or LCCO), heavy cycle oil (HCO, or HCCO), slurry (bottom stream, usually with an IBP above 795°F or 424°C). The products may vary depending on the configuration of the downstream systems and market needs.
The severe process conditions inside this tower, especially at the bottom section (high inlet temperature, high feed inlet momentum, high potential for fouling and pressure upsets) can be challenging to address during the design stage, and Koch-Glitsch offers specialized products that will allow for increased throughputs while improving the reliability and operational performance of the unit.
Slurry Pumparound (SPA) Section
When the heat or mass transfer needs in the SPA require the use of packing in this section, Koch-Glitsch can offer a solution of PROFLUX® 40 severe service grid used in combination with an enhanced weir trough liquid distributor, specifically designed for this application, that will allow for the best balance between performance (heat and mass transfer) and reliability (fouling and mechanical resistance). Other configurations using FLEXIGRID® severe service grid packing are also available.
Heavy Cycle Oil (HCO) Wash Section
A similar approach to the SPA section using PROFLUX® severe service grid can be offered if de-entrainment is the main driver of the HCO wash section. However, for refiners who believe that separation is vital, FLEXIPAC® structured packing with large crimp sizes can be proposed as a higher efficiency option. If trays are preferred, Koch-Glitsch can provide designs using VG-10 fixed valves that offer a compromise between cost and performance, and PROVALVE® trays can be used for higher capacity and even better fouling resistance. Koch-Glitsch can also provide special mechanical designs tailored to withstand severe uplift conditions in any section of the tower for any of the internals.
Pumparound and Fractionation Zones
Depending on the needs of the refiner, Koch-Glitsch can provide a wide variety of combinations of internal configurations throughout the tower to satisfy the mass and heat transfer needs for revamps, troubleshooting situations, and new designs. We strive to provide the best available solution to allow for mechanical resistance, performance optimization and run-length reliability.