becomes affordable, it is possible to create synthetic carbon-based fuels from CO2 and H2O by using the energy to reduce carbon and hydrogen.
Even hydrogen might not be feasible. If the cost drops to $30 per ton of CO2, hydrogen will still not be competitive because the distribution system for the hydrogen will be very expensive. If hydrogen is piped from a central power plant which collects its own CO2 to destinations across the country, it will cost a lot of money.
However, the dream of the hydrogen economy is to close the loop and have a renewable energy source to split water into oxygen and hydrogen, giving hydrogen to the consumer who then recreates water. If CO2 can be captured from the air, the same loop is slightly more complicated. The CO2 and hydrogen can be used to run an old-fashioned fissure trough to make gasoline. This means the ability to capture CO2 may actually open doors for carbon in any of its hydrocarbon forms to become an alternative energy carrier. The world may then no longer need fossil fuels if this alternative energy carrier to hydrogen can be used in a vehicle.
The future might hold a spectrum of pure carbon to pure hydrogen and, in that spectrum, there is a fuel of choice that can be oxidized. “At the point where you use it, you make CO2 and water, and you give it back,” Lackner said. In a situation where it is very easy to obtain hydrogen for an application—for example, a city bus in a bus fleet—hydrogen might be preferable. This opens up a whole new chemistry of sorting out what fuels are appropriate for the right circumstances and how many different ones can be supported.
New power plants, recovering CO2, and the chemical transformation of CO2 into a stable deposit, will all open doors. But there will have to be an energy revolution in the next 60 years. “If we did what we did the last 50 years, which was essentially doing the same thing slightly better, and incrementally more and more and more of it, we cannot repeat this for another 50 years,” Lackner said.