Difference in primary biogenic emissions and emissions in the molecule graph

[mabijkerk]

When I add 200 MW of biomass gasification to a blank nl2019 scenario and add 50% CCS, I get this scenario.

When I then want to query the primary biogenic CO2 of the biomass gasification with CCS node I get the following:

V(energy_hydrogen_biomass_gasification_ccs,primary_co2_emission_of_bio_carriers)

310,208,412.87184536

However, when I query the emissions of the node in the molecule graph I get:

MV(energy_hydrogen_biomass_gasification_ccs_co2,demand)

310,191,268.2188544

The result is just slightly different, but I would expect them to be the same. Would you know why this difference occurs @antw ?

[antw]

@mabijkerk Your scenario link is for a local copy of ETEngine. I can't see it. 😉

I was able to create identical results by setting a non-zero gasificiation capacity, and share to 0.5:

capacity_of_energy_hydrogen_biomass_gasification: 20.0
share_of_energy_hydrogen_biomass_gasification_ccs: 0.5

EACH(
  V(energy_hydrogen_biomass_gasification_ccs,primary_co2_emission_of_bio_carriers),
  # => 310,208.41287184536

  MV(energy_hydrogen_biomass_gasification_ccs_co2,demand)
  # => 310,191.2682188544
)

The molecule node specifies that its demand is set only by the input of torrefied_biomass_pellets. In my scenario there is a tiny amount of network gas arriving at the gasification node. The emissions from this gas accounts for the small difference:

PRODUCT(
  # Take the emissions of the network gas node.
  V(energy_national_gas_network_natural_gas, primary_co2_emission_of_bio_carriers),

  # Figure out how much of those emissions are due to biomass gasification.
  PRODUCT(
    V(EDGE(energy_hydrogen_biomass_gasification_ccs, energy_national_gas_network_natural_gas), parent_share),
    V(energy_national_gas_network_natural_gas, network_gas_output_conversion)
  )
)
# => 17.144652990944962

[mabijkerk]

Your scenario link is for a local copy of ETEngine

Oops, I didn't realise I was working on my local model. Thanks for the explanation @antw!

@redekok I see you worked on these nodes, is there a reason why the energy_power_ultra_supercritical_oxyfuel_ccs_lignite is able to capture CO2 based on both its inputs, while the energy_hydrogen_biomass_gasification_ccs can only capture the torrefied biomass pellets and not the network gas?

[redekok]

@mabijkerk I Can't remember this very well to be honest.. I think we just weren't aware that the gasification process also requires a bit of network gas (since the node key doesn't include network gas in its name).

[mabijkerk]

@redekok so would you be in favour of adding the network gas to the carriers that can be captured? Or do you know who might know more about the reasoning behind which carriers can be captured?

[mabijkerk]

Notifying @marliekeverweij: could you have a look?

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