Lifecycle optimization of a steel plant using circular economy strategies in the Middle East steel sector

Thesis Abstract

Increasing pressure on the Middle East steel sector to reduce environmental impact and improve resource efficiency motivates a study on lifecycle optimization of a steel plant through circular economy strategies. The research addresses the operational, economic, and environmental challenges of integrating material recovery, energy recovery, and recycling loops within conventional steelmaking processes to extend asset life, reduce virgin material intake, and lower lifecycle emissions. The aim is to develop a decision-support framework that enables a typical integrated steel plant in the region to iteratively optimize its material and energy flows across stages from raw input sourcing to end-of-life recycling, aligning technical feasibility with economic viability and regulatory compliance. Specific objectives are (i) to map current material and energy flows and identify hotspots for loss and emissions; (ii) to quantify potential circular economy interventions, including scrap integration, by-product valorization, slag and dust recycling, energy cascade, and product modularization; (iii) to develop and validate a lifecycle optimization model that links process-level decisions with plant-level metrics (cost, CO2 intensity, and resource productivity); (iv) to assess risk and resilience implications under regional macroeconomic and policy scenarios; and (v) to formulate a strategic roadmap for phased implementation within a representative plant. A mixed-methods design combines quantitative and qualitative approaches. The population comprises a representative integrated steel plant in the Middle East region, its supply chain partners, and industry suppliers; an estimated 60 plant personnel across operations, maintenance, and engineering units will constitute the core sample for quantitative data, complemented by 15 in-depth interviews with senior engineers and managers for qualitative insights. Data collection utilizes plant production records, energy and emission inventories (226 data points monthly over two years), material flow analysis data, and structured surveys. Instrument validity is established through content validation with a panel of four industry experts and a pilot test in a sister facility. Reliability is ensured via test-retest checks and Cronbach’s alpha for multi-item scales, aiming for ? ? 0.80. The analysis employs a lifecycle assessment (LCA) to quantify environmental impacts, a material flow analysis (MFA) to illuminate loop closures, and an optimization model integrating mixed-integer linear programming (MILP) to minimize lifecycle cost and greenhouse gas emissions subject to process, technical, and regulatory constraints. Regression analyses identify drivers of emissions reductions, while scenario analysis explores policy and market uncertainties. Theoretical framing draws on the circular economy theory and the resource-based view to connect internal capabilities with external value creation, and the dynamic capability framework guides organizational adaptation. A conceptual model links circular interventions to lifecycle outcomes, tested against empirical data to validate its predictive capability. Expected findings indicate substantial potential for circular interventions to reduce virgin material consumption by 25–40%, lower lifecycle CO2-equivalent emissions by 15–30%, and yield a favorable internal rate of return on identified investments within a 5–7 year horizon. By-product valorization, improved scrap quality control, and slag utilization are anticipated to deliver material cost savings of 8–12% per annum, while energy recovery through waste heat integration could cut auxiliary energy costs by up to 6%. Sensitivity analyses reveal that policy incentives, scrap price volatility, and access to efficient infrastructure significantly influence the magnitude and timing of benefits. The study contributes to knowledge by offering a transparent, plant-level optimization framework that integrates LCA, MFA, and MILP within a circular economy context tailored to the Middle East steel sector, bridging a gap between theoretical circular strategies and practical, financially viable deployment. It also advances methodological integration by coupling environmental life-cycle metrics with operational optimization in a single decision-support tool. The main conclusion posits that a staged, data-driven transition toward circular economy practices can achieve meaningful environmental gains without compromising plant competitiveness, provided that organizational capabilities and supplier networks are fortified. Practical recommendations include (i) implementing modular retrofit pathways prioritizing scrap handling, by-product recovery, and slag cementitious use; (ii) establishing supplier agreements and pricing mechanisms that stabilize scrap quality and supply; (iii) creating performance dashboards aligned with lifecycle indicators for management oversight; and (iv) pursuing policy engagement to leverage regional incentives and carbon pricing. Suggestions for further research encompass refining the model with dynamic market conditions, extending to multi-plant networks, and evaluating social implications of circular strategies within the regional steel workforce.