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Question about modeling the e-fuel pathway with FT tech. for SAF (biojet)
- Li
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1 month 4 weeks ago #587
by Li
Hi Don,I'd like to ask a question about modeling the e-fuel pathway for SAF (biojet) under GHGenius 5.02b (like the case similar to model in GREET). I understand that GHGenius 5.02b has an e-fuel pathway for e-diesel. If I want to model power-to-liquid SAF using Fischer-Tropsch technology, is there a way to modify the model within GHGenius 5.02b? The feedstock involves two scenarios: biogenic CO2 and off-gas industrial CO2 (from iron/steel plants or cement plants), with green hydrogen from solar or wind. If so, could you please provide guidance on how to approach the modeling or indicate where I should make the necessary modifications in the model?
Thanks in advance!
Sincerely,
Wen
Thanks in advance!
Sincerely,
Wen
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- doconnor
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1 month 3 weeks ago - 1 month 3 weeks ago #598
by doconnor
Replied by doconnor on topic Question about modeling the e-fuel pathway with FT tech. for SAF (biojet)
Wen
The inputs for this pathway are in column G, rows241 to 248. You can change the properties of the FT fuel on the Fuel Char sheet in row 88 and then the pathway will be a e-SAF pathway.
You can set the grid for the electricity for this pathway using the drop down menu in B34 on the input sheet and specifying the grid in row 21 on the Power Gen sheet.
For the CO2, enter the quantity G37 on the Alt Fuel sheet. The characteristics of the CO2 are entered row 113 on that sheet. Here you can add the energy requirements to capture the CO2. If the CO2 is not biogenic then a value of 1000 needs to be entered in J113.
The results on the Upstream HHV sheet will include the CO2 from fuel combustion.
Regards
Don O'Connor
The inputs for this pathway are in column G, rows241 to 248. You can change the properties of the FT fuel on the Fuel Char sheet in row 88 and then the pathway will be a e-SAF pathway.
You can set the grid for the electricity for this pathway using the drop down menu in B34 on the input sheet and specifying the grid in row 21 on the Power Gen sheet.
For the CO2, enter the quantity G37 on the Alt Fuel sheet. The characteristics of the CO2 are entered row 113 on that sheet. Here you can add the energy requirements to capture the CO2. If the CO2 is not biogenic then a value of 1000 needs to be entered in J113.
The results on the Upstream HHV sheet will include the CO2 from fuel combustion.
Regards
Don O'Connor
Last edit: 1 month 3 weeks ago by doconnor.
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- Li
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1 month 3 weeks ago #602
by Li
Replied by Li on topic Question about modeling the e-fuel pathway with FT tech. for SAF (biojet)
Hi Don,
Many thanks for your quick response and it is very helpful!!!
I have two follow up questions:
1) why 1000 needs to be entered in J113?Could you please share a bit more information, what does mean by this value and how it comes from?
2) Regarding the Upstream Results HHV tab -- BZ11 cell for FT electricity production, I am very confused by part of the equation: ......."MAX(0,'Alt Fuel Prod'!G37/'Fuel Char'!B88*1000000*12/44--'Fuel Char'!D88*1000*'Fuel Char'!F88"* (1-Input!B52)
-- MAX(0,'Alt Fuel Prod'!G37/'Fuel Char'!B88*1000000*12/44: probably means the carbon (not the carbon dioxide, because of the 12/44) mass per SAF energy (converted from mass of carbon in CO2 input to output fuel) , the unit is g carbon /GJ SAF;
-- Fuel Char'!D88*1000*'Fuel Char'!F88": probably means the the carbon (not the carbon dioxide, because Fuel Char'!F88 is the carbon fraction in the output fuel) mass per SAF energy, the unit is g carbon/GJ.
-- (1-Input!B52) means the (1-biogneic CO2 %)
so what's the meaning of the "MAX(0,'Alt Fuel Prod'!G37/'Fuel Char'!B88*1000000*12/44--'Fuel Char'!D88*1000*'Fuel Char'!F88", and why it is related to the SAF fuel production, since in my understanding, the carbon intensity related to fuel production is always resulted in process energy and catalyst/chemicals input and the direct emission related to the process.
Many thanks in advance for your help/response for the 2 question.
Sincerely,
Wen
Many thanks for your quick response and it is very helpful!!!
I have two follow up questions:
1) why 1000 needs to be entered in J113?Could you please share a bit more information, what does mean by this value and how it comes from?
2) Regarding the Upstream Results HHV tab -- BZ11 cell for FT electricity production, I am very confused by part of the equation: ......."MAX(0,'Alt Fuel Prod'!G37/'Fuel Char'!B88*1000000*12/44--'Fuel Char'!D88*1000*'Fuel Char'!F88"* (1-Input!B52)
-- MAX(0,'Alt Fuel Prod'!G37/'Fuel Char'!B88*1000000*12/44: probably means the carbon (not the carbon dioxide, because of the 12/44) mass per SAF energy (converted from mass of carbon in CO2 input to output fuel) , the unit is g carbon /GJ SAF;
-- Fuel Char'!D88*1000*'Fuel Char'!F88": probably means the the carbon (not the carbon dioxide, because Fuel Char'!F88 is the carbon fraction in the output fuel) mass per SAF energy, the unit is g carbon/GJ.
-- (1-Input!B52) means the (1-biogneic CO2 %)
so what's the meaning of the "MAX(0,'Alt Fuel Prod'!G37/'Fuel Char'!B88*1000000*12/44--'Fuel Char'!D88*1000*'Fuel Char'!F88", and why it is related to the SAF fuel production, since in my understanding, the carbon intensity related to fuel production is always resulted in process energy and catalyst/chemicals input and the direct emission related to the process.
Many thanks in advance for your help/response for the 2 question.
Sincerely,
Wen
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- doconnor
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1 month 2 weeks ago #611
by doconnor
Replied by doconnor on topic Question about modeling the e-fuel pathway with FT tech. for SAF (biojet)
Wen
We recognize that we have to make some updates to this pathway to make it align better with other pathways when it is a fossil carbon source that is being used.
When biogenic CO2 is used the pathway can be modelled quite simply, the challenges happen when fossil CO2 is used and the original source of the fossil CO2 no longer reports those emissions, then the responsibility to report those emissions falls to the e-fuel.
The first question is easy, 1000 is just 1000 g CO2 per kg of CO2. This is so the emissions from the CO2 do get accounted for if it is fossil CO2. It does show up in the production emissions rather than the fuel combustion emissions, we are still looking at different ways for moving some of these emissions to the fuel combustion stage.
The Max function is so that mot enough CO2 is entered into the system to balance the c in the fuel, the model won't calculate negative emissions.
The 1-B52 will allow for a blend of fossil and biogenic to be used in the pathway.
We are working on an update to the model to correct a few issues and we are looking at how we can address some of these issues for the fossil CO2 to fuels pathways.
Regards
Don O'Connor
We recognize that we have to make some updates to this pathway to make it align better with other pathways when it is a fossil carbon source that is being used.
When biogenic CO2 is used the pathway can be modelled quite simply, the challenges happen when fossil CO2 is used and the original source of the fossil CO2 no longer reports those emissions, then the responsibility to report those emissions falls to the e-fuel.
The first question is easy, 1000 is just 1000 g CO2 per kg of CO2. This is so the emissions from the CO2 do get accounted for if it is fossil CO2. It does show up in the production emissions rather than the fuel combustion emissions, we are still looking at different ways for moving some of these emissions to the fuel combustion stage.
The Max function is so that mot enough CO2 is entered into the system to balance the c in the fuel, the model won't calculate negative emissions.
The 1-B52 will allow for a blend of fossil and biogenic to be used in the pathway.
We are working on an update to the model to correct a few issues and we are looking at how we can address some of these issues for the fossil CO2 to fuels pathways.
Regards
Don O'Connor
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- Li
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1 month 2 weeks ago #612
by Li
Replied by Li on topic Question about modeling the e-fuel pathway with FT tech. for SAF (biojet)
Hi Don,
Much appreciated!
1) I now have a clearer understanding of your explanation regarding (1-B52).
2) For the 1000g CO2/kg CO2 (feedstock), if I understand correctly, this 1000g/unit results from fossil process energy/input allocated to the fossil CO2 when during fossil-based production occurs (e.g., at an iron/steel plant). Am I correct?
However, I have to admit that I still don’t quite understand your explanation about the formula:
MAX(0, 'Alt Fuel Prod'!G37/'Fuel Char'!B88*1000000*12/44-'Fuel Char'!D88*1000*'Fuel Char'!F88).
I’m a bit confused about the setting as well as the about the unit—why is it considering g carbon/GJ instead of g CO2 eq/GJ?
Sorry to disturb you, Don!
Sincerely,
Wen
Much appreciated!
1) I now have a clearer understanding of your explanation regarding (1-B52).
2) For the 1000g CO2/kg CO2 (feedstock), if I understand correctly, this 1000g/unit results from fossil process energy/input allocated to the fossil CO2 when during fossil-based production occurs (e.g., at an iron/steel plant). Am I correct?
However, I have to admit that I still don’t quite understand your explanation about the formula:
MAX(0, 'Alt Fuel Prod'!G37/'Fuel Char'!B88*1000000*12/44-'Fuel Char'!D88*1000*'Fuel Char'!F88).
I’m a bit confused about the setting as well as the about the unit—why is it considering g carbon/GJ instead of g CO2 eq/GJ?
Sorry to disturb you, Don!
Sincerely,
Wen
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- doconnor
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1 month 2 weeks ago #613
by doconnor
Replied by doconnor on topic Question about modeling the e-fuel pathway with FT tech. for SAF (biojet)
Wen
The 1000 g/kg accounts for the emissions from fossil based CO2. I think that most reporting programs will not count these emissions if the CO2 is captured and so they must be captured when these fuels are combusted.
I think that you are correct, there should be an additional factor of 44/12 in the equation.
Regards
Don O'Connor
The 1000 g/kg accounts for the emissions from fossil based CO2. I think that most reporting programs will not count these emissions if the CO2 is captured and so they must be captured when these fuels are combusted.
I think that you are correct, there should be an additional factor of 44/12 in the equation.
Regards
Don O'Connor
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- Li
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1 month 2 weeks ago #614
by Li
Replied by Li on topic Question about modeling the e-fuel pathway with FT tech. for SAF (biojet)
Thank you for your clarification, Don!
Wish you have a great Christmas holiday!
Sincerely,
Wen
Wish you have a great Christmas holiday!
Sincerely,
Wen
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