Carbon Recycling for Renewable Materials and Energy Supply

type="main"> The current flow of carbon for the production, use, and waste management of polymer-based products is still mostly linear from the lithosphere to the atmosphere with rather low rates of material recycling. In view of a limited future supply of biomass, this article outlines the options to further develop carbon recycling (C-REC). The focus is on carbon dioxide (CO 2 ) capture and use for synthesis of platform chemicals to produce polymers. CO 2 may be captured from exhaust gases after combustion or fermentation of waste in order to establish a C-REC system within the technosphere. As a long-term option, an external C-REC system can be developed by capturing atmospheric CO 2 . A central role may be expected from renewable methane (or synthetic natural gas), which is increasingly being used for storage and transport of energy, but may also be used for renewable carbon supply for chemistry. The energy input for the C-REC processes can come from wind and solar systems, in particular, power for the production of hydrogen, which is combined with CO 2 to produce various hydrocarbons. Most of the technological components for the system already exist, and, first modules for renewable fuel and polymer production systems are underway in Germany. This article outlines how the system may further develop over the medium to long term, from a piggy-back add-on flow system toward a self-carrying recycling system, which has the potential to provide the material and energy backbone of future societies. A critical bottleneck seems to be the capacity and costs of renewable energy supply, rather than the costs of carbon capture.