Assessing CO2 capture and storage for the decarbonization of a Bulgarian cement plant from an environmental and economic perspective

In line with the European Green Deal target of net-zero emissions by 2050, recent European Union policies are intensifying decarbonization pressures on energy-intensive industries. In the cement sector, the gradual phase-out of free emission allowances under the Carbon Border Adjustment Mechanism will require full carbon cost coverage by 2034, with carbon prices projected to rise to 130-160 €/t CO2 by 2030. Given that cement production accounts for 5-8% of global industrial CO₂ emissions, carbon capture and geological storage (CCS) represents a key mitigation pathway. This study assesses a complete CCS value chain for a real cement plant in Bulgaria through integrated process modelling, life cycle assessment (LCA), and techno-economic analysis (TEA). CO 2 capture is based on the Chilled Ammonia Process and includes liquefaction, pipeline transport, and geological injection, achieving an 87% capture efficiency (72.49 t CO2 /h). A detailed life cycle inventory from the plant gate to permanent storage was developed using Aspen Plus simulations and industrial data. Results show that CCS can reduce the cement’s plant carbon footprint from 1149 to 627 kg CO2-eq per ton of CO₂ stored, including residual uncaptured emissions. Capture and liquefaction dominate environmental impacts, while transport and injection contribute marginally. Further reductions to 393 and 282 kg CO2-eq per ton stored are achieved by capturing steam-related emissions and by using low-carbon heat, respectively. The system requires a CAPEX of 65.8 M€ and an OPEX of 78.9 €/t CO2 , making conventional CCS economically viable after 2030, while low-carbon heat integration or policy-based crediting enables cost-effective deployment in the short term.