Environmental process improvement of tire end-of-life treatment via pyrolysis through life cycle assessment
Abstract
End-of-life tire waste streams depict a global issue and can be recycled at the moment through retreating or reusing within limits. Thus, the current state-of-the-art technology to treat and recover energy from end-of-life tires represents incineration, which is associated with high environmental impacts. Thermal recycling via pyrolysis is a promising end-of-life treatment technology to recover material and energy from end-of-life tires to potentially reduce the environmental impacts. A life cycle assessment (LCA) is required to quantify additional environmental impacts and to relate potential environmental benefits from pyrolysis products for the end-of-life technology. In current literature, the LCA modeling of pyrolysis as an end-of-life tire treatment process uses insufficient system boundaries or life cycle data (1), focuses on the comparison of pyrolysis to end-of-life treatment technologies (2), and process improvements that could reduce environmental impacts are not sufficiently considered (3).To address the gaps, the objective of the study is to show the sustainable improvement potential of the pyrolysis process as a tire end-of-life treatment technology through a comprehensive environmental assessment through LCA. For the case study of the pyrolysis process, we want to show the environmental potential for an end-of-life technology in a sensitivity analysis regarding process design and crucial process parameters. We identify hot-spots within the pyrolysis end-of-life treatment process system that led to high environmental impacts. Additionally, we perform a potential analysis for the environmental impacts of the pyrolysis process regarding future scenarios for energy and process systems. In a broader context, we want to show a general methodology for an environmental improvement of current end-of-life treatment technologies. The results of the environmental assessment should serve as an indicator for the elastomer industry and in particular tire manufacturers for the development of end-of-life treatment technologies.