Determination of environmental impacts of the plastic recycling industry through life cycle assessment

The escalating crisis of plastic waste on a global scale represents one of the most critical environmental challenges of our time, profoundly intensifying a suite of interconnected problems including the rapid depletion of finite natural resources, alarming rates of biodiversity loss, and widespread habitat destruction. This linear "use-dispose model" economic model is increasingly recognized as unsustainable, creating immense pressure on planetary systems. Consequently, the strategic imperative to transition towards a circular economy, which prioritizes resource efficiency and waste elimination, has elevated the importance of plastic recovery and recycling activities from a simple waste management solution to a fundamental pillar of sustainable industrial policy. This thesis addresses this urgent global context by conducting a meticulous and quantitative environmental analysis of a specific operation within Turkey's non-hazardous plastic waste recovery sector. The study focuses explicitly on the operations of "Şam Yapı A.Ş. Sakarya Branch," with the core objective of quantifying and evaluating the environmental impacts associated with the production of one kilogram of recycled low-density polyethylene (rLDPE) granule. The aim is to move beyond generalized assumptions and provide a data-driven, granular understanding of the environmental costs and benefits inherent in the recycling process, thereby offering actionable insights for improving sustainability within the industry. The methodological foundation of this research is a comprehensive Life Cycle Assessment (LCA), conducted in accordance with the ISO 14040 and 14044 standards, which provides a structured framework for evaluating the environmental aspects and potential impacts associated with a product throughout its entire life cycle. For this study, the system boundaries encompassed the journey from the acquisition of post-consumer plastic waste as a raw material to the final output of rLDPE granule, a valuable secondary raw material for manufacturing. To ensure methodological rigor and reliability, a detailed inventory of all relevant inputs (including energy, water, and transportation) and outputs (such as emissions to air and water) was compiled through direct field studies and meticulous data collection from the facility's operations. This robust inventory dataset was then modeled and analyzed using the SimaPro software, a leading tool in the LCA discipline renowned for its extensive databases and analytical capabilities. A defining strength of this study is its multi-methodological approach to impact assessment. To ensure analytical robustness and provide a cross-validated, holistic perspective, three distinct, internationally recognized impact assessment methods were applied concurrently: CML-IA baseline V3.05, ReCiPe 2016 Midpoint (H), and IMPACT 2002+. This tripartite approach ensured that the findings were not an artifact of a single modeling choice, thereby offering a reliable and multi-faceted perspective across a wide spectrum of impact categories, including climate change, human health, ecosystem quality and resource depletion. The quantitative results of the LCA present a detailed and nuanced picture of the environmental footprint of rLDPE granule production, successfully identifying and quantifying the specific processes that function as environmental "hotspots." The analysis unequivocally demonstrated that the most significant environmental impacts, particularly on human health and ecosystem quality, originate from within the facility's production boundaries. Two operational lines were identified as the primary contributors to the total environmental burden. The first is the granule line process, which includes energy-intensive stages such as extrusion, melting, and pelletizing. The substantial electricity demand for these thermal and mechanical processes directly translated into major contributions to impact categories like global warming potential (due to carbon emissions from the electricity grid) and fossil resource depletion. The second major hotspot is the washing line process, which is critical for the dekontamination of incoming plastic waste. This process exhibited a significant environmental footprint due to its dual dependence on high volumes of water and the energy required for heating, pumping, and machinery operation, making it a key driver of the facility's water footprint and associated energy related emissions. Beyond the factory gates, the study determined that logistical and supply chain activities constitute a considerable and often underappreciated portion of the overall environmental footprint. A pivotal finding was the facility's heavy reliance on imported plastic waste, which necessitates long-distance international transportation via a combination of maritime shipping and, more impactfully, extensive road freight. This logistics network was shown to generate substantial emissions, with measurable and serious effects in categories such as climate change from fuel combustion, ecosystem quality from atmospheric pollutants, and resource consumption from the use of diesel and other fossil fuels. However, a crucial and positive finding of the research was the identification and evaluation of the company's proactive environmental management practices, which serve to effectively mitigate the absolute environmental load of its operations. Notably, the implementation of a closed-loop water management system, where wastewater from the washing line is treated on-site and reused within the process, dramatically reduces freshwater consumption and minimizes polluted discharge. Similarly, the partial integration of solar energy via rooftop panels directly displaces grid electricity, thereby reducing the carbon footprint and fossil resource depletion associated with the plant's energy-intensive operations. These clean production technologies play a vital role in counterbalancing the inherent impacts of production and elevate the company's overall sustainability performance. Based on the empirical evidence generated by the Life Cycle Assessment (LCA), this study culminates in the formulation of a series of strategic, evidence-based recommendations, which are meticulously designed to guide the facility toward a state of significantly reduced environmental footprint. These proposals are strategically targeted at the environmental hotspots (specifically, the granule production line, the washing process, and the logistics network) identified by the comprehensive analysis. The recommendations include, first, pursuing advanced energy and water efficiency measures within the granule and washing lines, a critical intervention given their high consumption profiles. This could involve the adoption of high-efficiency motors, the implementation of advanced process control systems for optimal resource utilization, and the integration of heat recovery technologies to capture and reuse waste thermal energy. Concurrently, a second, and equally critical, recommendation advocates for a substantial expansion of on-site renewable energy generation capacity. Increasing the share of solar power, for instance, is paramount to achieving a deeper decarbonization of the facility's electricity supply, thereby directly mitigating the carbon intensity embedded in its core manufacturing processes and reducing its reliance on the fossil fuel-based grid. A third strategic axis focuses on the comprehensive optimization of the logistical supply chain, which was revealed as a major contributor to the overall impact. This optimization necessitates a multi-faceted approach, including the implementation of advanced logistics software for route and load factor optimization (to minimize fuel consumption per ton-kilometer), the investigation and execution of modal shifts (from high-impact road transport to more environmentally benign alternatives, such as rail, where infrastructure and economics permit), and a strategic, long-term initiative to source a greater proportion of post-consumer plastic waste from local or domestic markets. This latter initiative is crucial for curtailing the substantial environmental costs, particularly greenhouse gas emissions and air pollutants, associated with long-distance, import-dependent transportation. It is therefore anticipated that the granular findings and the robust methodological framework presented in this thesis will provide a solid, scientific, and data-driven foundation for substantively enhancing sustainability practices within the broader plastic recovery sector. By offering a transparent, rigorous, and methodologically sound case study, this research provides concrete and actionable roadmaps for analogous enterprises (including recyclers and compounders) seeking to benchmark, diagnose, and improve their environmental performance. Ultimately, it is projected that this work will contribute meaningfully to the wider adoption, nuanced understanding, and effective operational implementation of circular economy principles on an industrial scale, thereby supporting the essential and ongoing transition towards a more sustainable, resilient, and resource-efficient future for the plastics industry.