Towards Green Steel in India’s Small and Medium Enterprise Steel Sector: A Critical Review of Cluster Structures, Product Flows, Energy Use and Carbon Footprints

Green steel transitions in emerging economies are currently planned around large integrated plants, while the small and medium enterprise (SME) segment that dominates finished steel output remains poorly characterized. This review consolidates the environmental evidence on India’s secondary steel sector, which supplies nearly 65% of national finished steel through more than 8500 units spanning coal-based direct reduced iron (DRI), induction furnace, electric arc furnace, steel re-rolling, foundry, and forging operations. Using an integrative scoping design that combines the peer-reviewed literature, government publications, industrial energy audits, and cluster assessments, the review maps process routes, regional clusters, product flows, and energy and carbon footprints, identifying the source, reference year, system boundary, and confidence level of each principal value. The sector consumed approximately 11.8 Mtoe (137,234 GWh) and emitted an estimated 58.2 Mt CO2 in 2019–2020, with coal-based DRI contributing about 52% of sector emissions, 60% of steelmaking-route emissions, and roughly twice the specific energy consumption of international benchmarks. Water use remains a critical evidence gap. The resulting route- and cluster-resolved baseline provides the foundation from which green production pathways for SME steel systems can be identified and the plant-level measurement priorities that credible net-zero planning requires can be specified.