distillation units at the Jamnagar Refinery. It has helped to reduce significant energy consumption in the upstream medium- pressure (MP) steam heater of the desalters in the crude preheat train. Divided wall column (DWC) for significant energy saving In the fluid catalytic cracking (FCC) unit, the first column of the two sequential naphtha
Figure 3 Crude column overhead heat recovery
Figure 4 FCC naphtha splitter
splitters was modified to a DWC configuration to recover a high-purity, high-octane iC5 stream from the light naphtha (see Figure 4 ). FCC flue gas heat recovery project The flue gas cooler (FGC) (see Figure 5 ) downstream of the FCC power recovery turbine (PRT) is used to generate high-pressure (HP) steam from waste heat. However, the temperature of the flue gas leaving the FGC to the stack was higher.In addition, the significant import of MP steam from the captive power plant (CPP) for the FCC’s internal consumption is energy-intensive. New FGC modules were installed as part of an ENCON project downstream of the existing HP steam generator to recover waste heat exiting the stack. Glass air preheater installation An air preheater (APH) is typically installed in the flue gas circuit of a crude heater to recover heat from the flue gases and preheat the combustion air. This process helps reduce fuel costs. At the Jamnagar Refinery, existing APHs have been revamped for certain process unit to recover more waste heat. In the crude heater, a cast-iron APH followed by a glass APH has been installed, achieving significant energy savings. There are plans to replicate this setup in another crude processing train at the Jamnagar Refinery.
Hea r t cut naphtha
1
C naphtha
NS1
Feed from depentaniser
LCO
LCO
HCO
HCO
Heavy naphtha
Figure 4 Divided wall column (DWC)
helps maintain a strong emphasis on energy conservation.
ENCON case studies Overhead heat recovery project
The overhead vapours from the crude atmospheric column (see Figure 3 ) were partially condensed using an air cooler. To recover heat loss, helical baffle heat exchangers were installed to exchange heat between crude oil and overhead vapours. These exchangers are positioned in parallel and vertically to provide proper water washing on the naphtha side and to prevent corrosion. This design will increase the crude inlet temperatures to the downstream heat exchangers in the cold preheat train. This approach is replicated across all crude
Ceramic coating in process heaters Heat loss occurs from the inner surface of
Refining India
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