The use of by-products in new materials

We live in a world where there is a climate emergency, a depletion of primary raw materials resulting in material insecurity and combined with a depletion of energy resources that requires the uptake of renewable resources. These factors, amongst others, have caused a reassessment of how we view our resources and how efficiently we use and design products and materials. This reassessment is the paradigm change from a linear to a circular economy. In this chapter, we will consider the use of by-products or ‘secondary raw materials’ rather than primary products that are mined, extracted, or synthesised. The concepts of ‘end of waste’ and the approaches necessary for circular design using by-products will be evaluated. A model of circular design for by-products that considers sustainable development goals, registers of by-products, and adequate environmental monitoring is developed.