Circularity assessment of industrial heat exchanger and water treatment systems integration

Highlights • Circularity assessment of energy and water recovery systems in a ceramic industry. • Rooftop rainwater harvesting integration analysis and assessment. • Definitions for circular and linear classification of water flows. • Traceability of water resources analysis in the industrial sector. • Benchmark and scenario analysis assessment performed. Water recycling and reusing strategies in industries have been promoted to reduce freshwater consumption. In addition, Heat Pipe Heat Exchanger technology has been employed successfully, resulting in the reduction of natural gas consumption and mitigating greenhouse gas emissions. It is important to assess the true benefits of the application of these Circular Economy strategies. Therefore, this work assesses the integration of a Heat Pipe Condenser Economiser (HPCE) and a water treatment system in a ceramic industry. Additionally, rooftop rainwater harvesting is integrated into the industry. The CE assessment methodologies and selected indicators measure the efficiency of the transition from a linear to a circular economy and identify strategies for optimisation. However, the interactions between human and natural systems related to the abstraction of resources and release of outflows are not considered. This is important to understand potential disruptions when implementing circular actions. Therefore, the assessment focuses on circular principles such as resource traceability and value created by implemented actions, and through resource flow and circular action indicators, the intrinsic circularity of system integration is quantified. The assessment showed the integration of both systems and the rooftop rainwater harvesting increased the Circular Water Flow and the Water Withdrawal Reduction up to 33.73% and 22.88%, respectively. Moreover, it demonstrates that the HPCE integration increased the Recovered Energy Contribution up to 19.98%. This indicates the system’s integrations increased circular performance over the baseline scenario. Additionally, the assessment enabled a scenario analysis which aided in identifying further strategies to improve the circular actions, such as reducing freshwater withdrawal.