Solarpunk technology

there's concepts like biorefinery where we take plastic and agricultural waste and put it into a heavily modified oil refinery and out comes biochar and some chemical feedstocks (e.g. ethylene) for making new virgin-grade plastic. Depending on the design it can be more carbon efficient than carbon capture, but in general these industries use a gigantic amount of energy while producing less plastic and much less gasoline/diesel than a normal oil refinery.