## 4 Results  
### Life Cycle Assessment of Different ELT Recycling Methods  
The exhaustive LCA analyses are performed on all ELT alternatives with different manufacturing scenarios and then compared with each other in terms of various environmental impact categories (health, climate change, human toxicity, water use and abstraction, water eutrophication, and other impacts) (see Table 2). However, it should be noted that the presented literature may not always correlate due to different system boundaries and assumptions and, of course, the chosen categories of impact that were targeted for analysis. Scenario 1, representing the landfill disposal of ELTs, was excluded from Table 2 and Figure 3 due to its minimal calculated environmental impact under normal conditions, despite being banned in the European Union for its hazardous nature. The risk of uncontrolled tire fires in landfills, which could release 1680-2270 kg of CO2 Eq per ton of ELTs into the atmosphere, poses a significant environmental catastrophe. Based on these factors, the research team decided not to include data from this scenario in the comparative analysis. Various scenarios are considered, and, in all of them, renewable energy sources are used to support the processes. Scenario 1 considers the incineration of ELTs. The energy recovered from incineration is utilized as heat or electricity, contributing to energy efficiency and reducing dependency on fossil fuels. However, CO2 emissions from the incineration process are not included in the environmental impact calculations, as the focus is on the energy recovery benefits provided by renewable energy integration. Scenario 2 expands on the first by including the CO2 emissions generated during the incineration of ELTs. While renewable energy is used to power the incineration process,the associated carbon footprint of the incineration itself is accounted for. This provides a more comprehensive understanding of the environmental impact of this disposal method by factoring in the emissions from tire combustion. Scenario 3 is where car tires are mechanically recycled into crumb rubber, steel fibers, and textile waste using renewable energy to power the recycling process. This approach minimizes the environmental impact by reducing fossil fuel use during recycling. The recovered materials are suitable for further applications, such as use in cement composites or as raw materials in other industries, contributing to a circular economy. Scenario 4 is similar to car tire recycling; this scenario focuses on the recycling of truck tires. Truck tire recycling typically yields a higher proportion of steel fibers due to their composition, making it an efficient method of recovering valuable materials while reducing environmental impacts. Scenario 5 examines the environmental impact of producing new tires. While the integration of renewable energy reduces the dependency on fossil fuels, the extraction and use of virgin materials, as well as the energy-intensive production process, still result in significant environmental impacts. This scenario serves as a baseline for comparing the sustainability of alternative ELT management approaches. The LCA results highlight notable differences across disposal methods. Recycling one ton of ELTs emits between 36.1 to 122.9 kg CO2 Eq., whereas incineration, with emissions unaccounted, results in approximately 69.3 kg CO2 Eq., a figure that rises significantly with full emissions accounting for 1693.6 kg CO2 Eq. The production of 1 ton of new tires has a high impact, emitting 2766.6 kg CO2 Eq., emphasizing the environmental benefits of recycling over manufacturing from raw materials. In the recycling pathway for car and truck tires, it becomes obvious that different issues are arising, and eutrophication is one of them. One group with a higher eutrophication impact is the car tire at 0.9 kg PO4 Eq., opposite to the truck tire eutrophication impact measured at 0.1 kg PO4 Eq..