Life cycle assessment of a vapor absorption refrigeration system applied to a university building in Northeast Brazil

Abstract

Due to the increase in global warming and the growing demand for thermal comfort in tropical climate regions, refrigeration systems have become essential to ensure adequate conditions in residential, commercial, and institutional environments. At the same time, efforts are being made to reduce the environmental impacts associated with their use. In this context, the present study conducts a life cycle assessment (LCA) of a double-effect vapor absorption refrigeration system (SFAVDE) with a cooling capacity of 352 kW, using direct natural gas combustion as an energy source. The main objectives of this work are: i. to provide a life cycle assessment for SFAVDE technologies used to meet the cooling demand of a specific university building in Northeastern Brazil and ii. to perform a dominance analysis to identify the main contributors to environmental impacts in the SFAVDE. The LCA study was conducted using the ReCiPe endpoint method (humanitarian, average weighting – H/A). Simulations were performed using the open-source software openLCA version 1.10.3, utilizing the Ecoinvent 3.7.1 life cycle inventory database. The simulation results showed that, in the ecosystem, human health, and natural resources categories, the greatest environmental impacts were caused by climate change and ecosystems (17.19%), climate change and human health (27.18%), and fossil depletion and natural resources (43.70%). Regarding the dominance study, the results indicated that, for the transport and operation stages, the main impacts were air transport (91.00%) and natural gas usage (97.00%), respectively. In the disposal stage of the SFAVDE, copper recycling resulted in a 34.61% reduction in environmental impact compared to landfill disposal. Therefore, to mitigate the environmental impacts of the SFAVDE, it is recommendedto assess transportation alternatives, utilize renewable fuels during the operation phase, and prioritize the reuse of copper during the manufacturing and disposal stages.