Evaluation and Ranking of Cement Alternatives in South Africa Using Combine Life Cycle Assessment and Multi- criteria Decision-Making Methods

Abstract Choosing the most suitable alternatives can be challenging in process engineering. Typically, there is a need to evaluate and rank alternatives using various criteria, such as environmental impact, when making decisions. This paper employs a novel integration of Life Cycle Assessment (LCA) and Multi-Criteria Decision-Making (MCDM) methods to evaluate the sustainability of different cement alternatives in South Africa. The LCA assesses the environmental impact, considering 18 midpoint categories, while Complex Proportional Assessment (COPRAS) and Additive Ratio Assessment (ARAS) methods were used as MCDA methods to rank and select the best alternatives. Across 18 impact categories, including global warming, ozone depletion, ecotoxicity, and resource scarcity, CEM I cement exhibited notable global warming emissions, ranking fourth. COPRAS and ARAS methods systematically ranked alternatives based on impact categories, consistently identifying CEM II/B-V cement as the most preferred alternative. This top ranking was attributed to its low environmental impact and high utility score. Notably, CEM III/A cement, despite low global warming emissions, ranked least preferred due to concerns about raw material-related environmental impacts. The paper highlights environmental hotspots for each cement type and underscores the importance of sustainable fuel and raw material selection in production. The results emphasize the necessity of reducing clinker content, exploring alternative fuels and raw materials, and adopting interventions like carbon capture and storage to enhance sustainability in cement production. The paper concludes that the integrated LCA and MCDM approach provides valuable insights for decision-makers in the cement industry, aiding the pursuit of more sustainable practices and calling for further research on the environmental impact of specific raw materials and fuels.