The circular economy plays an essential role in materials reinsertion in a productive chain, and it is a supportive way to achieve economic growth and change the linear economy based on fossil resources.
The reuse of by-products from conventional industrial processes as feedstock in innovative technological routes leads to a novel approach for biorefinery development in the circular economy. An integrated close-to-zero waste system exploiting a sequential process with anaerobic digestion can be proposed as a model system for the circular economy transition.
Implementing anaerobic digestion technology can be a strategy for the management by-products and the recovery of biogas and digestate. The biogas produced can be upgraded to biomethane, electricity, and thermal energy. The use of biogas can be an alternative to the decentralized production of electric energy, supporting the diversification of energy resources. Thermal energy can also be used by the industries. It can avoid the use of natural gas-based on fossil fuel, which is an environmental perspective to decrease greenhouse gases emissions.
Therefore, the development of a new management system based on anaerobic digestion could be a sustainable model to contribute to the development of the agriculture and food sector by decreasing the wastes generated and reducing the greenhouse gas emissions by producing renewable resources and marketable products, reaching the goals of the circular economy.