Refuse-derived fuel in cement manufacturing: a systematic review of research trends, gaps and future research directions

Purpose This study provides a comprehensive overview of refuse-derived fuel (RDF) as a sustainable alternative for cement co-processing, highlighting its role in decarbonising the cement industry and advancing circular economy (CE) objectives. Design/methodology/approach A systematic literature review was conducted following the preferred reporting items for systematic reviews and meta-analyses guidelines to synthesise existing knowledge. A total of 211 scholarly articles (1991–July 2025) were subjected to descriptive analysis. 48 records, including seven regulatory documents, were selected for detailed content analysis. Findings The descriptive analysis indicates that research output on RDF in cement manufacturing has fluctuated but is showing an upward trend, driven by regulatory pressure and growing industry interest. Studies are concentrated in developed nations, with regions such as Africa and Latin America being underrepresented. Content analysis reveals ongoing ambiguity between RDF and solid recovered fuel, as these terms are often used interchangeably in research and regulations. This review clarifies RDF's role within the CE framework and the waste management hierarchy, while identifying key gaps in standardisation, quality assurance, environmental assessment and policy development. Addressing these gaps is critical to advancing sustainable global adoption. Originality/value This study systematically maps the evolution and current landscape of RDF research in cement manufacturing, offering a clear research agenda. By identifying critical knowledge gaps and proposing future directions, it provides a valuable reference for academics, policymakers and industry practitioners. The findings aim to inform decision-making, support the integration of RDF into cement manufacturing and contribute to global sustainability and decarbonisation efforts.