https://www.wired.com/story/cheap-nanoparticles-pave-the-way-for-carbon-neutral-fuel/

The Svartsengi power station sits on the banks of the Blue Lagoon, an artificial geothermal spring and one of Iceland’s most popular tourist attractions. For decades, it has supplied Icelanders with geothermal electricity and heat. The rub is that extracting this renewable energy from the ground requires fossil fuels to run the pumps. So in 2011, an Icelandic energy startup called Carbon Recycling International built the George Olah plant, which captures Svartsengi’s CO2 emissions and turns them into a carbon-neutral fuel.

The idea for CO2 recycling was around long before the George Olah plant became the first to put it into practice. The idea is to take carbon dioxide emitted by power plants and use some chemical wizardry to turn it into useful fuels like propane or methane. Aside from CO2, the main ingredients in this process are hydrogen and a metallic catalyst. Cook it all together at high temperatures and voilà: You’ve got yourself a tank of liquid hydrocarbon fuel. Although emissions from hydrocarbon fuels are exactly the problem this process is trying to solve, in principle capturing the emissions from the newly made fuels can create a closed loop. The world pumps out nearly 40 billion tons of CO2 each year, so converting even a small fraction of that into carbon-neutral fuel would be a win.