Recent achievements of Industrial Symbiosis in the steel sector based on the Symbio-Steel project: a review

Industrial Symbiosis refers to a collaborative approach, including synergies among companies for the transaction of resources, such as materials, energy, water, and by-products, thus resulting in mutual benefits and promoting a Circular Economy approach. Over the past decades, the steel sector was committed to reduce waste production as well as reuse waste and by-products to exploit them as a resource. Significant results in Industrial Symbiosis implementation have been achieved, creating new synergies and networks with other industrial sectors. Nonetheless, a comprehensive analysis of technical and non-technical barriers, that hinder the successful implementation of Industrial Symbiosis within the steel sector, can help implement an integrated and synergic approach encompassing and merging results and experience already achieved. This review paper presents a comprehensive overview of recent studies on the research trends on Industrial Symbiosis, considering drivers and barriers to its implementation, and maps the recent achievements related to the steel sector, by analysing the impact of some significant case studies. For instance, CO 2 valorisation in flue gases and steel slags to produce silicates and carbonates via mineral carbonation and CO 2 capture, re-use and sequestration by industrial symbiosis activities involving the steel and ammonia/urea industries are presented. The literature review based on selected publications allowed tracing the evolution of Industrial Symbiosis over the last few years. The assessment of main lines for research in Industrial Symbiosis allows identifying the challenges for future research. The analysis of implementation of new technologies can help to create new symbiotic networks and further developments and scenarios for the steel industry in a future characterized by material scarcity, decarbonization, and more stringent environmental legislation.