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Can somebody explain to me why we need to switch to electric cars when we have Fischer-Tropsch to produce fuel literally out of thin air? We could keep all the

by sprash 7y ago

Can somebody explain to me why we need to switch to electric cars when we have Fischer-Tropsch to produce fuel literally out of thin air? We could keep all the existing infrastructure while having zero CO2 impact. I think digging up loads of Lithium and Cobalt and plastering the country with charging stations is neither more sustainable nor less environmentally harmful.

kennywinker 7y ago
I'm not intimately familiar with Fischer-Tropsch, but reading the list of existing plants on the wikipedia page https://en.wikipedia.org/wiki/Fischer–Tropsch_process#Commercialization https://en.wikipedia.org/wiki/Fischer–Tropsch_process#Commer... Virtually all of them are producing synthetic fuel using other fossil fuels. E.g. natural gas or coal. One is using pulp/paper waste, and the other is using a combination of natural gas and landfill gas. So while the process promises to convert "a mixture of carbon monoxide and hydrogen into liquid hydrocarbons" it does not seem that anybody is doing that. You are totally right that there is nothing wrong with liquid hydrocarbon fuels, as long as they are sourced from clean energy, but the fact that nobody is doing it even at a small scale seems to indicate to me that it's not (yet?) viable for some reason.
- sprash 7y ago
  > Virtually all of them are producing synthetic fuel using other fossil fuels. Recently a plant was demonstrated by DLR in Spain that produced Fuel from air directly only with solar power: https://www.dlr.de/content/en/articles/news/2019/02/20190613_solar-fuel-breakthrough.html https://www.dlr.de/content/en/articles/news/2019/02/20190613... Edit: apparently this converts H2O and liquid CO2 to a "synthesis gas" CO + H which then can easily transformed into any fuel you want via Fische-Tropsch. So the only step that is missing is liquefying CO2 which can be done via conventional solar power using electricity. As far as I see it we have all pieces to the puzzle. Electric cars don't make sense anymore and are actually more harmful to the environment because of all the exotic materials used and the losses from transport of electrical power across the whole country. Also keep in mind that much of the electricity is still produced using coal.
chillacy 7y ago
This has been known for since the 20s, Nazi germany used the process in WW2 but not by choice. There are inefficiencies with any conversion like that, from electrical to chemical. Whether or not that's better than the externalities from rare earth mining, I'm not sure.
wcoenen 7y ago
The Fischer-Tropsch process is about 50% efficient. (This is starting from biomass, it will be worse starting with air and extracting CO2, which is hard because less than 0.05% of air is CO2) https://www.sciencedirect.com/science/article/pii/S0016236113002019 https://www.sciencedirect.com/science/article/pii/S001623611... Then the fuel is burned. Internal combustion engines are typically 20% efficient. https://en.wikipedia.org/wiki/Internal_combustion_engine?wprov=sfla1 https://en.wikipedia.org/wiki/Internal_combustion_engine?wpr... So burning synthetic fuel would be 50% * 20% = 10% efficient. Compare that to an electricity roundtrip through a li-ion battery which is 95% efficient, and an electric motor which is 85% efficient at converting electrical energy to mechanical. Even with additional transmission losses, the pure electric system is going to be vastly more energy efficient.
- sprash 7y ago
  Most electricity is produced by burning coal heating up water and sending it through a turbine. The efficiency is limited by the maximum the carnot cycle can give you. In general less than 60%. Still not as bad as 10%, sure. But if you get your energy with solar cells we could get into regions where the efficiencies are comparable. All Fisher-Tropsch needs is heat and using solar you have plenty of that.
  - redisman 7y ago
    So when you argue for your point, electricity for the process comes from solar but when you argue against someone elses point it comes from coal?
    - sprash 7y ago
      All I'm saying is, when talking about efficiency the electricity source should be considered as well. Besides that efficiency is not the right metric to ask for here. Environmental impact is the important metric. Destroying existing infrastructure, destroying vast ecosystems in Chile to mine Lithium, enslaving Africans to mine Cobalt, use lots of energy to purify silicon for solar cells, building a more distributed power grid, installing charging stations everywhere. All of this has environmental impact. If you can make synthetic fuel with solar power in some desert (Nevada is big enough), you can keep all the old stuff and still be able to save the planet.
philipkglass 7y ago
1) Without emissions pricing/regulations, synthetic liquid fuel costs more to produce than fossil-derived liquid fuels, so it is unprofitable. 2) Even assuming that there were emissions pricing/regulations that kept fossil fuels in the ground, synthetic liquid fuel is much more capital intensive and energy intensive to produce than the corresponding amount of electricity needed to move a car N kilometers. Synthetic fuels have a place in the future for applications that require high energy density like aircraft, rockets, and long distance shipping. But burning synfuels in legacy internal combustion engine vehicles is, generally speaking, not going to have a lower systemic cost than replacing ICE vehicles with battery electric vehicles and charging them with clean electricity. A sketch of the problem: the Oryx Gas to Liquids plant is a modern Fischer-Tropsch plant that produces about 34,000 barrels (5.4 million liters) per day of liquid hydrocarbon fuels: https://qp.com.qa/en/QPActivities/Pages/SubsidiariesAndJointVenturesDetails.aspx?aid=37 https://qp.com.qa/en/QPActivities/Pages/SubsidiariesAndJoint... It cost about a billion dollars to build. A corresponding electrical synfuel plant would cost significantly more. You could eliminate the natural gas reformer and desulfurization processes, but would need to add: 1) CO2 separation unit sufficient to extract 14.2 million kilograms of CO2 from the atmosphere, daily (to supply the carbon found in 5.4 million liters of synthetic diesel fuel). Since the air contains ~400 ppm CO2, you need to process about 35.5 billion kilograms of air per day to get sufficient input CO2. Capital costs: wild-ass guesses, because nobody has built anything like this at scale. There's a recent claim that it direct air capture could cost "as low as" $94 per ton of CO2 [1]. That would come to 1.3 million dollars per day. 2) Enough hydrogen per day to turn all that CO2 into liquid fuel. Assuming an empirical "average diesel" formula of C12H24, you need 12 moles of CO2 and 48 moles of H2 to make a mole of diesel: 12 CO2 + 48 H2 -> C12H24 + 12 H2O. In terms of mass, that's .18 kilograms of hydrogen for every kilogram of CO2 -- 2.58 million kilograms of hydrogen per day. 3) A clean source of hydrogen. Electrolysis driven by clean electricity is the only process demonstrated at scale. Assuming it takes 46 kWh of electricity to produce a kilogram of hydrogen from water, and that plant capital costs are $975 per kg-H2/day [1], that's an electricity consumption of 118,860 megawatt hours per day plus an electrolyzer complex cost of $2.5 billion. 4) Electricity to drive the electrolyzers. The very cheapest electricity from hydro, nuclear, or renewable sources is somewhere between $20-$30 per megawatt hour. Such low priced electricity isn't available everywhere; in some countries, even large industrial buyers pay $40 and up. At the lower end that's 2.4 million dollars per day for electricity. Adding it all up, the electricity and air capture costs alone come to about 69 cents per liter of diesel in costs. That is even though I have tried to make very charitable assumptions about how low the costs could be kept. The wholesale price of diesel in the US is currently about 51 cents per liter: https://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=PET&s=EMA_EPD2D_PWG_NUS_DPG&f=M https://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=PET&s=E... I don't know how to properly amortize the extra capital investments to give a per-liter figure, but keep in mind that just adding the hydrogen electrolyzers triples the capital requirements for the whole complex. Note that I have budgeted nothing for labor either. Finally, how much transportation do you get out? 5.4 million liters of diesel provides 85 million vehicle-kilometers in a 2019 Chevrolet Cruze: https://www.fueleconomy.gov/feg/PowerSearch.do?action=alts&path=3&year1=2019&year2=2020&vtype=Diesel&srchtyp=newAfv https://www.fueleconomy.gov/feg/PowerSearch.do?action=alts&p... 118,860,000 kWh of electricity provides 645 million vehicle-kilometers in a Tesla Model 3 (assuming 80% generation-to-battery efficiency): https://pushevs.com/2017/08/01/tesla-model-3-efficiency-impressive/ https://pushevs.com/2017/08/01/tesla-model-3-efficiency-impr... The battery-electric propulsion solution delivers more than 7 times as much range per kilowatt hour of electricity spent, compared to clean synthetic fuel, and even more per dollar spent. [1] https://www.sciencemag.org/news/2018/06/cost-plunges-capturing-carbon-dioxide-air https://www.sciencemag.org/news/2018/06/cost-plunges-capturi... [2] https://www.energy.gov/eere/fuelcells/doe-technical-targets-hydrogen-production-electrolysis https://www.energy.gov/eere/fuelcells/doe-technical-targets-... -- using the "2015 target" numbers for centrally located electrolysis.

by sprash 7y ago

kennywinker 7y ago

I'm not intimately familiar with Fischer-Tropsch, but reading the list of existing plants on the wikipedia page https://en.wikipedia.org/wiki/Fischer–Tropsch_process#Commercialization https://en.wikipedia.org/wiki/Fischer–Tropsch_process#Commer... Virtually all of them are producing synthetic fuel using other fossil fuels. E.g. natural gas or coal. One is using pulp/paper waste, and the other is using a combination of natural gas and landfill gas. So while the process promises to convert "a mixture of carbon monoxide and hydrogen into liquid hydrocarbons" it does not seem that anybody is doing that. You are totally right that there is nothing wrong with liquid hydrocarbon fuels, as long as they are sourced from clean energy, but the fact that nobody is doing it even at a small scale seems to indicate to me that it's not (yet?) viable for some reason.

sprash 7y ago
> Virtually all of them are producing synthetic fuel using other fossil fuels. Recently a plant was demonstrated by DLR in Spain that produced Fuel from air directly only with solar power: https://www.dlr.de/content/en/articles/news/2019/02/20190613_solar-fuel-breakthrough.html https://www.dlr.de/content/en/articles/news/2019/02/20190613... Edit: apparently this converts H2O and liquid CO2 to a "synthesis gas" CO + H which then can easily transformed into any fuel you want via Fische-Tropsch. So the only step that is missing is liquefying CO2 which can be done via conventional solar power using electricity. As far as I see it we have all pieces to the puzzle. Electric cars don't make sense anymore and are actually more harmful to the environment because of all the exotic materials used and the losses from transport of electrical power across the whole country. Also keep in mind that much of the electricity is still produced using coal.

chillacy 7y ago

This has been known for since the 20s, Nazi germany used the process in WW2 but not by choice. There are inefficiencies with any conversion like that, from electrical to chemical. Whether or not that's better than the externalities from rare earth mining, I'm not sure.

wcoenen 7y ago

The Fischer-Tropsch process is about 50% efficient. (This is starting from biomass, it will be worse starting with air and extracting CO2, which is hard because less than 0.05% of air is CO2) https://www.sciencedirect.com/science/article/pii/S0016236113002019 https://www.sciencedirect.com/science/article/pii/S001623611... Then the fuel is burned. Internal combustion engines are typically 20% efficient. https://en.wikipedia.org/wiki/Internal_combustion_engine?wprov=sfla1 https://en.wikipedia.org/wiki/Internal_combustion_engine?wpr... So burning synthetic fuel would be 50% * 20% = 10% efficient. Compare that to an electricity roundtrip through a li-ion battery which is 95% efficient, and an electric motor which is 85% efficient at converting electrical energy to mechanical. Even with additional transmission losses, the pure electric system is going to be vastly more energy efficient.

sprash 7y ago
Most electricity is produced by burning coal heating up water and sending it through a turbine. The efficiency is limited by the maximum the carnot cycle can give you. In general less than 60%. Still not as bad as 10%, sure. But if you get your energy with solar cells we could get into regions where the efficiencies are comparable. All Fisher-Tropsch needs is heat and using solar you have plenty of that.
- redisman 7y ago
  So when you argue for your point, electricity for the process comes from solar but when you argue against someone elses point it comes from coal?
  - sprash 7y ago
    All I'm saying is, when talking about efficiency the electricity source should be considered as well. Besides that efficiency is not the right metric to ask for here. Environmental impact is the important metric. Destroying existing infrastructure, destroying vast ecosystems in Chile to mine Lithium, enslaving Africans to mine Cobalt, use lots of energy to purify silicon for solar cells, building a more distributed power grid, installing charging stations everywhere. All of this has environmental impact. If you can make synthetic fuel with solar power in some desert (Nevada is big enough), you can keep all the old stuff and still be able to save the planet.

philipkglass 7y ago

1) Without emissions pricing/regulations, synthetic liquid fuel costs more to produce than fossil-derived liquid fuels, so it is unprofitable. 2) Even assuming that there were emissions pricing/regulations that kept fossil fuels in the ground, synthetic liquid fuel is much more capital intensive and energy intensive to produce than the corresponding amount of electricity needed to move a car N kilometers. Synthetic fuels have a place in the future for applications that require high energy density like aircraft, rockets, and long distance shipping. But burning synfuels in legacy internal combustion engine vehicles is, generally speaking, not going to have a lower systemic cost than replacing ICE vehicles with battery electric vehicles and charging them with clean electricity. A sketch of the problem: the Oryx Gas to Liquids plant is a modern Fischer-Tropsch plant that produces about 34,000 barrels (5.4 million liters) per day of liquid hydrocarbon fuels: https://qp.com.qa/en/QPActivities/Pages/SubsidiariesAndJointVenturesDetails.aspx?aid=37 https://qp.com.qa/en/QPActivities/Pages/SubsidiariesAndJoint... It cost about a billion dollars to build. A corresponding electrical synfuel plant would cost significantly more. You could eliminate the natural gas reformer and desulfurization processes, but would need to add: 1) CO2 separation unit sufficient to extract 14.2 million kilograms of CO2 from the atmosphere, daily (to supply the carbon found in 5.4 million liters of synthetic diesel fuel). Since the air contains ~400 ppm CO2, you need to process about 35.5 billion kilograms of air per day to get sufficient input CO2. Capital costs: wild-ass guesses, because nobody has built anything like this at scale. There's a recent claim that it direct air capture could cost "as low as" $94 per ton of CO2 [1]. That would come to 1.3 million dollars per day. 2) Enough hydrogen per day to turn all that CO2 into liquid fuel. Assuming an empirical "average diesel" formula of C12H24, you need 12 moles of CO2 and 48 moles of H2 to make a mole of diesel: 12 CO2 + 48 H2 -> C12H24 + 12 H2O. In terms of mass, that's .18 kilograms of hydrogen for every kilogram of CO2 -- 2.58 million kilograms of hydrogen per day. 3) A clean source of hydrogen. Electrolysis driven by clean electricity is the only process demonstrated at scale. Assuming it takes 46 kWh of electricity to produce a kilogram of hydrogen from water, and that plant capital costs are $975 per kg-H2/day [1], that's an electricity consumption of 118,860 megawatt hours per day plus an electrolyzer complex cost of $2.5 billion. 4) Electricity to drive the electrolyzers. The very cheapest electricity from hydro, nuclear, or renewable sources is somewhere between $20-$30 per megawatt hour. Such low priced electricity isn't available everywhere; in some countries, even large industrial buyers pay $40 and up. At the lower end that's 2.4 million dollars per day for electricity. Adding it all up, the electricity and air capture costs alone come to about 69 cents per liter of diesel in costs. That is even though I have tried to make very charitable assumptions about how low the costs could be kept. The wholesale price of diesel in the US is currently about 51 cents per liter: https://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=PET&s=EMA_EPD2D_PWG_NUS_DPG&f=M https://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=PET&s=E... I don't know how to properly amortize the extra capital investments to give a per-liter figure, but keep in mind that just adding the hydrogen electrolyzers triples the capital requirements for the whole complex. Note that I have budgeted nothing for labor either. Finally, how much transportation do you get out? 5.4 million liters of diesel provides 85 million vehicle-kilometers in a 2019 Chevrolet Cruze: https://www.fueleconomy.gov/feg/PowerSearch.do?action=alts&path=3&year1=2019&year2=2020&vtype=Diesel&srchtyp=newAfv https://www.fueleconomy.gov/feg/PowerSearch.do?action=alts&p... 118,860,000 kWh of electricity provides 645 million vehicle-kilometers in a Tesla Model 3 (assuming 80% generation-to-battery efficiency): https://pushevs.com/2017/08/01/tesla-model-3-efficiency-impressive/ https://pushevs.com/2017/08/01/tesla-model-3-efficiency-impr... The battery-electric propulsion solution delivers more than 7 times as much range per kilowatt hour of electricity spent, compared to clean synthetic fuel, and even more per dollar spent. [1] https://www.sciencemag.org/news/2018/06/cost-plunges-capturing-carbon-dioxide-air https://www.sciencemag.org/news/2018/06/cost-plunges-capturi... [2] https://www.energy.gov/eere/fuelcells/doe-technical-targets-hydrogen-production-electrolysis https://www.energy.gov/eere/fuelcells/doe-technical-targets-... -- using the "2015 target" numbers for centrally located electrolysis.