This study pioneers a combined Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) evaluation of an industrial symbiosis (IS) case involving waste heat recovery from a pulp and paper mill to a tomato greenhouse in Sweden. Unlike previous studies that assess environmental or economic aspects separately, this research provides a holistic assessment quantifying both environmental burdens and economic feasibility. A comparative analysis framework is applied, evaluating a symbiotic real case of waste heat recovery versus conventional greenhouse tomato production in the Netherlands and subsequent import to Sweden. LCA examines greenhouse gas emissions, eutrophication, toxicity, land use, and resource depletion, while LCC assesses total ownership costs, including Capital and Operational Expenditures. The findings demonstrate that the IS scenario significantly reduces greenhouse gas emissions and operational costs while enhancing energy efficiency. This work fills a gap in IS literature, offering a replicable framework for sustainable greenhouse operations. The results highlight the potential of IS to improve resource efficiency, promote circular economy strategies, and foster sustainable practices in the agri-food sector.

Industrial symbiosis (IS) plays a crucial role in enhancing sustainability within industrial ecosystems by facilitating the exchange of waste, by-products, energy, and resources among different industries. This collaborative approach reduces resource consumption, minimizes waste generation, lowers disposal costs, and creates economic opportunities through synergistic relationships. This study focuses on the production of potassium nitrate (KNO₃) in the Escombreras industrial area in Spain, employing life cycle assessment (LCA) and life cycle cost analysis (LCC) to evaluate the impact of IS strategies. The ReCiPe method, implemented through SimaPro software and supported by market data from the Ecoinvent 3.8 database, is used for a comparative analysis between conventional KNO₃ production and improved technologies that promote circular economy principles. The LCA and LCC methodologies provide a comprehensive evaluation of both environmental and economic performance, considering key factors influenced by IS synergies. Results demonstrate significant environmental and economic benefits from the integration of IS into KNO₃ production, revealing the potential for improved sustainability and competitiveness through circular economy practices. This research provides valuable insights into how IS can enhance both environmental performance and cost-efficiency in industrial processes. These findings support the integration of IS as a viable pathway toward sustainable and cost-effective fertilizer production.