The circular economy is based on waste management and the generation of new inputs that are alternatives to the current materials in use. For the current status of the world, greenhouse gases are emitted that are a main cause of climate change and that are caused by the increasingly widespread extractive economy based on the concept of “extract-produce-throw.” The concept of circularity is increasingly discussed among companies, governments, and citizens, in the context of how to develop their activities in an environmentally benign and ecoefficient way. This involves reducing or avoiding waste as much as possible, substituting materials that are used today for more advantageous ones, and utilizing new technology for the processing of waste. Wastes come in many forms, e.g., plastic, food, and manufacturing residuals.