Element-based material flow analysis to identify unexplored industrial symbiosis opportunities

The cement, glass, steel and ceramics sectors consume large amounts of raw materials and generate large amounts of by-products and wastes. Industrial symbiosis is a promising approach to reduce waste production and raw material extraction in manufacturing sectors. A key task within industrial symbiosis is the identification of symbiotic matches, in which a by-product output from one sector can be used to replace a raw material input from another sector. The lack of a systematic, compositionally-grounded approach to identifying symbiotic matches is a barrier to greater implementation of industrial symbiosis. In this study, element-based material flow analysis is developed as a novel approach to help identify previously unexplored cross-sectoral matches for industrial symbiosis. Element-based mapping was carried out on the material flows in the cement, glass, steel, ceramics sectors in the United Kingdom. Al, Ca, Fe, Mg and Si together comprise >95% of elemental flows for both input raw materials and output by-products. However, elemental flows of by-products are only ~14% of raw material elemental input flows across the cement, glass, steel and ceramics sectors. A Similarity Index based on Euclidean distance was developed to evaluate similarity in elemental composition between by-product outputs and raw material inputs. An initial screening was conducted on 103 potential matches, based on their similarity in elemental composition; a subsequent screening step based on a literature review and an industry-based workshop yielded six promising yet unexplored matches. This approach demonstrates value beyond conventional industrial symbiosis matching approaches, for improving circularity in industrial materials production.