Environmental Life Cycle Assessment of Refrigerator Modelled with Application of Various Electricity Mixes and Technologies

Assessing the environmental performance of optimized commercial refrigerators with alternative refrigerants and remote monitoring system: A cradle-to-grave life cycle assessment

Refrigerators, as other cooling systems, are responsible for a significant parcel of anthropogenic emissions since they are essential and heavy appliances that use energy during its lifespan and are loaded with refrigerant gases. Three types of commercial refrigerators and their new versions, with incorporated CO2 as refrigerant gas and an wireless system for maintenance monitoring (WSMM) were investigated to evaluate how optimization could impact on the environmental performance during their entire life cycle. This study conducted a comprehensive Life Cycle Assessment (LCA) of the refrigerators, from the production to their end-of-life. The findings revealed that the use phase and the raw materials were responsible for most of the environmental impact throughout the refrigerators' life cycle. Key impact categories such as Fossil Resource Scarcity, Freshwater Eutrophication, and Global Warming were particularly affected, largely due to the electricity mix in the use phase. Additionally, the extraction and production of raw materials, specifically steel and copper, made significant contributions to Terrestrial Ecotoxicity and Human Carcinogenic Toxicity categories. The optimization measures impacted mainly in the energy consumption during the use phase, resulting in a notable reduction of approximately 57 % for models that underwent refrigerant change and 60 % for the model that underwent both refrigerant change and electronic system installation. As a result of decreased energy consumption, there was a significant decrease of 13 %-16 % across all impact categories, underscoring the positive environmental implications of these optimization strategies.

Comparative environmental performance of pavement structures considering recycled materials and regional differences

The construction of pavements incorporating reclaimed asphalt pavement (RAP) is taking place around the world, implying the necessity to quantify their net environmental impacts. Life cycle assessment (LCA) is a popular method to analyze the environmental impacts of a product along the whole value chain, providing guidance to practices and technologies from environmental perspectives. However, the LCA research of RAP-modified pavement is seldom performed in Brazil. In addition, as an important source of uncertainties, there is also need of discussion regarding the geographical and technological characteristics in the LCA of pavements. For these motivations, this paper performs a cradle-to-gate LCA to compare the environmental performance of asphalt pavement in Brazil and Switzerland, using the practical rates of RAP use. The functional unit was defined based on the same traffic volume and service life of asphalt pavements, where the mix design and pavement structures follow the standards of the two countries. The results showed that RAP recycling can improve the environmental performance of hot asphalt mixtures in both countries. Binder amount has a high environmental burden and its reduced use by adding RAP has a positive environmental effect. Type of fuel also plays an important role in LCA. In Brazil, it is not recommended to use heavy oils as fuel during the mixing process if other options such as methane gas is available. The results show that the Swiss production of asphalt mixture had lower environmental impact. Nevertheless, a strategic location of material suppliers and mixing plants could lower the transportation distances, improving its environmental performance.

Prediction of Stirling-Cycle-Based Heat Pump Performance and Environmental Footprint with Exergy Analysis and LCA

The use of Stirling-cycle-based heat pumps in high-temperature applications and waste heat recovery at an industrial scale is of increasing interest due to the promising role in producing thermal energy with zero CO2 emissions. This paper analyzes one such technology as developed by Olvondo Technology and installed at the pharmaceutical company AstraZeneca in Sweden. In this application, the heat pump used roughly equal amounts of waste heat and electricity and generated 500 kW of steam at 10 bar. To develop and widen the use of a high-performance high-temperature heat pump that is both economically and environmentally viable and attractive, various analysis tools such as exergy analysis and life cycle assessment (LCA) can be combined. The total cumulative exergy loss (TCExL) method used in this study determines total exergy losses caused throughout the life cycle of the heat pump. Moreover, an LCA study using SimaPro was conducted, which provides insight into the different emissions and the overall environmental footprint resulting from the construction, operation (for example, 1, 8, and 15 years), and decommissioning phases of the heat pump. The combined results were compared with those of a fossil fuel oil boiler (OB), a bio-oil boiler (BOB), a natural gas-fired boiler (NGB), and a biogas boiler (BGB).