Plastics and liquid fuels can be manufactured starting from carbon dioxide and hydrogen. Hydrogen of course can be produced via the electrolysis of water with s

Plastics and liquid fuels can be manufactured starting from carbon dioxide and hydrogen. Hydrogen of course can be produced via the electrolysis of water with solar electricty. Carbon Recycling International already operates a commercial methanol plant for making methanol using renewable electrolytic hydrogen and carbon dioxide. This article "Process Advantages of Direct CO2 to Methanol Synthesis" has a lot of details: https://www.frontiersin.org/articles/10.3389/fchem.2018.00446/full https://www.frontiersin.org/articles/10.3389/fchem.2018.0044... Methanol is a portable liquid that can be used directly as a fuel. It is also convertible to the olefins (alkenes) propylene and ethylene, the two most common plastic feedstocks. China has built millions of tons of capacity for methanol-to-olefins in the past decade, though unfortunately their input methanol is mostly produced from coal. See e.g. this recent plant that came on stream: "World’s largest single-train methanol-to-olefins plant now operating" https://www.chemengonline.com/worlds-largest-single-train-methanol-to-olefins-plant-now-operating/ https://www.chemengonline.com/worlds-largest-single-train-me... Helium is one of the very few mineral resources that is simultaneously industrially important, scarce, difficult to substitute, and exhibits poor prospects for higher sustainable terrestrial production. The other few elements in this small club are (IMO) the platinum group metals and rhenium.