Dividing Wall Column GT-DWC In Aromatics Industry
The following are the typical applications of GT-DWC in an aromatics complex:
- Benzene / Toluene Column
- Toluene / Xylene Column
- Deheptanizer / Xylene Column
- Debutanizer / Deisobutanizer Column
- Reformate Splitter
GT-DWC offers a 20-30% reduction in energy along with a 30% reduction in CAPEX for the above applications.
GTC Single Shell Absorption / Distillation Columns (GT-ADC)
GT-ADC combines two unit operations (absorption and distillation) in single shell. GT-ADC offers a significant advantage for columns using partial condensers.
GT-ADC Operating Principle
- Performs two unit operations (absorption and distillation) in a single column.
- Lights are removed on the feed side of the dividing wall by reboiled absorption.
- Top liquid product is separated from heavies on the other side of the dividing wall via distillation.
The benefits of GT-ADC are explained using a conventional TA stabilizer as an example.
Conventional Stabilizer Design
- Typically operates at higher pressure (8.5 kg/cm2g)
- C5 / off gas spillover due to partial condensation. C5 product stream has higher vapor pressure.
- Higher bottoms temperature (233 C). Fired heater or HP steam required as heating medium.
- Lower operating pressure (2.7 kg/cm2g)
- Clear separation between off gas and C5 product. C5 product has low vapor pressure and can be blended directly with gasoline.
- Higher C5 recovery.
- Lower bottoms temperature (188 °C). Lower temperature allows heat integration with other process streams.
The following table provides a comparison between a conventional Stabilizer design vs. GT-ADC stabilizer.
In the event that improved product purity is not desired, GT-ADC will provide a 20-30% reduction in energy for the same product specifications as in the conventional design.