The development of greener and more sustainable processes has been a major focus of research and industrial activities in process development due to a number of important reasons: realisation of the contribution of industry on the increase of atmospheric carbon dioxide (CO2), the depletion of reserves of fossil feedstocks, and increasing problems with waste management. A key concept for the future sustainable society is the development of circular industrial structures which requires the integration of waste process streams as feedstocks. This results in feedstock components that are both new to the supply chain, and are highly functionalised. Provided we can solve the problem of separation of waste product streams, the remaining important question is where best to add these molecules into the current and the emerging circular industrial systems.