stream or flare. To also maintain profitability, it is essential that valuable products are routed to the optimum disposition. GT-LPG Max technology from Sulzer may be used to improve efficiency and lower the cost of the gas separation process. This process utilises a dividing wall column to enhance the recovery of C₃ and C₄ (see Figure 1 ). The light, intermediate, and heavy fractions are separated in a single column with the top dividing wall instead of multiple columns. A vertical wall divides the top of the column into two sections: absorption and fractionation. Feed is supplied to the absorption section, where a heavy liquid recovers the C₃ and C₄ components, and non-condensables are sent overhead. The fractionation side concentrates and collects the C₃. In addition to lower capital and operating expenses, the benefits of using a single dividing wall column include higher recovery of valuable components, lower emissions through reduced energy consumption, and the potential to debottleneck downstream units or shift to increased petrochemical production. This was the objective of a major petrochemical plant in Asia, which has recently commissioned and is now operating a GT-LPG Max unit. The unit treats a portion of the off-gases which had been fed to one of two fuel gas treating units (see Figure 2 ). The unit was severely bottlenecked, so C₃ and C₄ components were being sent to the flare. A valuable product was
O - gas
Top liquid product
Feed
Bottom product is the absorbing medium
Figure 1 GT-LPG Max top dividing wall column
possible. However, as industry adjusts to a net zero future, these same revamps opportunities, which exist across the refinery, offer another step towards achieving decarbonisation goals. What follows are three examples of revamps where Sulzer technology has been used to both increase profitability and contribute to industry decarbonisation. Reduced carbon emissions in gas processing Inefficient gas treating operations can be a significant source of CO₂ emissions. LPG from mixed fuel gas streams is difficult to recover and typically requires a multi-column approach. Still, valuable components can be lost to a fuel
Fuel gas system 1
Fuel gas system 2
To cracker complex
HP
HP
O - gases
O - gases
Flare Fuel gas
O - gases
LP
Flare Fuel gas
O - gases
LP
C (tankage) C (tankage) C (tankage)
GT-LPG M ax
C , C , H
Figure 2 Facility configuration after installation of GT-LPG Max
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