Expensive carbon capture and burial demonstrations
The US Department of Energy is spending $7 billion to demonstrate capturing 6 million tons of CO2 from the atmosphere. Companies are also paid to capture and store CO2 underground with tax credits of $180 per ton. To what end? DOE’s billion ton 2050 goal might cost $180 billion a year, just to remove 3% of global CO2 annual emissions, never mind historical CO2. ETH Zurich estimates direct air-capture of CO2 will cost $230-$540 per ton. Experts at US National Bureau of Economic Research justify high costs by reporting $1,056 per ton Social Cost of Carbon Dioxide. Removing annual CO2 emissions at that price would consume a third of world GDP.
Burial costs are high. The US offers CO2 burial tax credits of $85 per ton, or $60 if injected into an oil field to push up more oil. That wasn’t economic enough for the shuttered Petra Nova project. Where to store the CO2? Even liquified CO2 occupies three times the volume of oil that creates it, and the world burns four cubic miles of oil per year, plus coal and natural gas.
Making CO2 into fuel
Reviving CO2 requires ample, cheap hydrogen. Hydrogen atoms can replace oxygen atoms in CO2 and chain the resulting hydrocarbon links into fuels such as diesel, gasoline, and jet fuel. George Olah’s 1994 Nobel Prize essay previewed this.
“As atmospheric carbon dioxide is available to all people on the Earth this will enable mankind to liberate itself from dependence on fossil fuels … energy could come from safe nuclear power plants … also diminish the danger of global warming by removing and recycling the rising carbon dioxide content of the atmosphere.”
Olah envisioned net-zero hydrocarbon fuel synthesized from CO2 captured from the atmosphere; hydrogenated in refineries; burned in standard internal combustion engines of cars, trucks, and planes; emitting CO2 back to the atmosphere. Such CO2 recycling can cut mining and burning fossil fuels that increase atmospheric CO2.
Expensive hydrogen demonstrations
The US DOE is spending $8 billion on hydrogen hubs to demonstrate hydrogen use and production. The industrial steam-reforming process harvests hydrogen from methane (CH4) but produces CO2, which some clean hydrogen projects will capture and bury. Even more money will be spent via the Inflation Reduction Act which pays companies a $3 subsidy for each kilogram of low-carbon hydrogen produced.
Some hydrogen hubs will use electrolysis to separate H2O into hydrogen and byproduct oxygen. Low cost electrolyzers and cheap electricity are critical to compete with hydrogen from methane. Intermittent electricity from wind and solar sources reduces the duty cycle for expensive electrolyzers to about a third, raising depreciation costs. Full time nuclear enables cheaper hydrogen.
Cheap hydrogen
Solid oxide electrolysis cells (SOECs) from Bloom Energy and Topsoe can benefit from using both nuclear heat and nuclear electricity to separate hydrogen from H2O. New nuclear technology of high temperature gas reactors and molten salt reactors provide heat over 700°C, enabling both SOEC and copper-chlorine cycle production cycles, which can produce nuclear hydrogen at $1 per kilogram. Only nuclear power can provide the continuous, clean electricity at 3 cents per kilowatt-hour and heat at 1 cent needed to make cheap hydrogen.
Hydrogen itself is not a very practical vehicle fuel. It is expensive to compress or chill hydrogen enough to transport to fueling stations and carry in a vehicle. But hydrogen is less expensive if produced and used at a co-located refinery to make CO2 into fuel. A co-located nuclear power plant cooled with flowing seawater can provide dissolved CO2.
Cheap CO2
Sea-capture can be less costly than air-capture because the sea already captures a third of mankind’s emitted CO2, where it’s 130 times more concentrated than in the atmosphere. An electrochemical technology, pH-swing, can remove CO2 from seawater by dividing the flow into two streams, one acidic, one basic. The CO2 can be bubbled out of the acidic stream, which is then combined back with the basic stream, swinging the seawater pH back to normal. Pacific Northwest National Laboratory and MIT studies estimate such CO2 costs at $20-$56 per ton. Captura and Equatic startups are each testing pH-swing systems on the Pacific coast, estimating costs under $100 per ton.
The US Navy Research Lab developed electrochemical cells that free both CO2 and H2 from seawater. Their 2012 jet fuel cost estimates were $3-$6 per gallon. Bosch estimates future synthetic fuel costs of $4-$6 per gallon. Such net zero fuels are potentially competitive with fossil fuels.
The future
Net zero fuel from revived CO2 will allow the US and the world continue to use existing internal combustion engine vehicles. The US can become independent of China’s domination of rare earths and metals production for batteries and magnets for electric vehicles.
To be competitive with fossil fuels, we need hydrogen at $1 per kilogram and CO2 under $100 per ton. The recent White House announcement of “steps to bolster domestic nuclear industry” will not make electricity and heat costs low enough to synthesize fossil-competitive net zero fuels. The US must reduce nuclear energy costs by overturning NRC regulations that ignore societal benefits in favor of assuaging unfounded, exaggerated fears of radiation. ThorCon is bypassing NRC to build molten salt reactors in Indonesia. We need to engage expertise of the refinery and chemical industries, not castigate them. Dow is an exemplary leader building high temperature gas reactors for its Seadrift plant in Texas.
We must look beyond impossibly expensive, ineffective projects to reduce CO2 warming and instead rejuvenate the maligned nuclear energy and refining technologies the US originally developed.
Capturing CO2 from the atmosphere and burying it in the ground strikes me as sophomoric. Besides sequestering twice as much oxygen as carbon, reducing the amount of CO2 in the atmosphere by such artificial means would only encourage additional emissions of CO2 from combustion of fossil fuels by creating a perception that the CO2 problem is not all that bad. The only sensible solution is to stop emissions of CO2 by using renewable energy, including nuclear energy.
Seafuel is a common-sense solution to the CO2 emissions problem. Instead of treating CO2 as a "bad" compound to be got rid of, Seafuel uses CO2 as a useful compound for energy transport, storage, and use, resulting in net zero emissions of CO2 into the atmosphere. The planet could recover to pre-industrial levels of CO2 within a few decades of ending CO2 emissions.
I'm not sure if it's better to reduce iron ore with hydrogen or with electrolysis, as Boston Metal is pioneering.