Optimizing Ethiopian greenhouse gas inventories with customized clinker-specific emission factors in the cement sector

Abstract Cement, a fundamental component of concrete, holds significant importance in global construction and infrastructure development. Despite being predominantly produced and consumed locally, the impact of cement extends globally, particularly in terms of energy consumption and greenhouse gas (GHG) emissions. Uncertainties surround the quantification of Ethiopia's CO2 emissions, leading to notable discrepancies among various sources. These disparities stem from factors such as country-specific CO2 emission factors, variations in statistical standards, and challenges in obtaining production data, especially for clinker and cement outputs. This study addresses these issues by emphasizing emission factors and defining CO2 accounting boundaries. This research uniquely employs detailed measurements at the factory level for clinker and cement production, providing comprehensive insights into chemical composition and environmental impacts across eight prominent cement industries in Ethiopia. Data was gathered through on-site surveys and sampling techniques, adhering to standardized methodologies outlined by the Intergovernmental Panel on Climate Change (IPCC). The study incorporates methods categorized under IPCC tier one and two calculators for provincial, production line, and national integrations. Key findings include nuanced variations in CaO and MgO concentrations, crucial for understanding raw material sources and production methodologies. The determination of an Ethiopian-specific CO2 emission factor for clinker (0.49 t CO2/t) highlights technological and efficiency gaps compared to global benchmarks. Moreover, analysis of clinker-to-cement ratios indicates that by optimizing production processes, a reduction of up to 4.3% in CO2 emissions is achievable, aligning with international sustainability standards. By addressing these methodological and data challenges, this study contributes to a more accurate assessment of GHG emissions in Ethiopia's cement industry. It underscores the need for updated emission factors and refined methodologies to inform policy decisions and foster sustainable practices in global construction.