Business challenge, situation before
Actual situation:
CO2 emitted by Steam Producers is not always reallocated to the units, due to the complexity of some intermediate steps.

How to:

• Take the specificity of each producers ?
• Deal with Cogeneration (Steam and Electricity) ?
• Blend different pressure levels ?
• Take into consideration Processing consuming HP steam but releasing MP or LP Steam ?
• Take into consideration counter pressure Steam Turbines ?
  Identify lack of instrumentation, or faulty steam flowmeters ? 

Details of the solution / TotalEnergies answer
TotalEnergies has developed the following tools to answer above challenges:

• Definition of the ‘CO2 intensity index’ of Steam producers and Steam Streams (tCO2/tSteam)
• Inclusion in a ‘Steam Stream’ template, used for all networks streams.
• Extensive usage of the Steam functions available in PIAF
• To link the CO2 intensity index to the Enthalpy of the Steam Stream
• Models of each Pressure levels of complex steam networks (even with steam exchanges between neighbor plants)
• Each Network branch has Inlets and Outlets, allowing to calculate the balance in terms of mass flowrate, but also in terms of equivalent CO2

Results & benefits
Some of the benefits:

• Comprehensive description in AF of the Steam Networks
• Reallocation of CO2 to the consumers
• Help in understanding and optimizing the Energy consumption of the Process units.

Takeaways & next steps
PIAF is not only effective in the modelling of single assets, but also in the representation of utility networks. Adding the Steam CO2 reallocation to the direct emissions at Unit level gives a clear view of the Actual CO2 intensity (tCO2/t feed) of a process unit.
A similar methodology could be applied to Hydrogen Network, as a typical Refinery as several producers, sometimes H2 import(s), and many consumers.

Global Note
This presentation is a continuation of the one made during the AVEVA World 2022 in Amsterdam, dealing with the Emissions of Combustion Equipment.

Audience (attendees)
Energy Engineers, Process Engineers, Data engineers.