Life cycle assessment of industrial symbiosis in Songmudao chemical industrial park, Dalian, China

Industrial symbiosis is an eco-industrial model to achieve the sustainable development of industrial parks through the exchange of byproducts, especially for the chemical industries which consume a lot of resources and discharge large amounts of pollutants. To highlights the advantages of this arrangement, we identified in and around the synthetic gas chemical industry chain of Songmudao chemical industrial park, Dalian, China. This chain involves seven facilities exchanging water, materials, and energy across an industrial cluster. The life cycle assessment method was used to evaluate each material substitution for primary energy and three environmental impact categories: primary energy, greenhouse gas (GHG) emission, acidification potential, and eutrophication potential. Each material exchange included avoided production and reduced use of virgin materials, avoided treatment or disposal of the byproducts, and any necessary pre-processing or transportation of local byproducts. All exchanges exhibited positive net saving across all environmental impact categories. The results show environmental benefits of the sharing of byproduct resources accrued in a life cycle basis include 13.63 thousand TJ of primary energy, 1218 thousand tCO2e of GHG, 5054.95 tSO2e of acidification, and 215 tPO43+e of eutrophication. The greatest savings occur as a result of sharing steams between the cogeneration power plant and other facilities. In total, the environmental savings realized by this chemical industrial cluster are significant, and industrial symbiosis is an important way for government to meet its environmental goals and promote this eco-industrial model in China. The government should attach importance to industrial symbiosis and make it a feasible method in energy policy.