This paper presents an assessment of the cost performance of CO₂ capture technologies when retrofitted to a cement plant: MEA-based absorption, oxyfuel, chilled ammonia-based absorption (Chilled Ammonia Process), membrane-assisted CO₂ liquefaction, and calcium looping. While the technical basis for this study is presented in Part 1 of this paper series, this work presents a comprehensive techno-economic analysis of these CO₂ capture technologies based on a capital and operating costs evaluation for retrofit in a cement plant. The cost of the cement plant product, clinker, is shown to increase with 49 to 92% compared to the cost of clinker without capture. The cost of CO₂ avoided is between 42 €/t_CO2 (for the oxyfuel-based capture process) and 84 €/t_CO2 (for the membrane-based assisted liquefaction capture process), while the reference MEA-based absorption capture technology has a cost of 80 €/t_CO2. Notably, the cost figures depend strongly on factors such as steam source, electricity mix, electricity price, fuel price and plant-specific characteristics. Hence, this confirms the conclusion of the technical evaluation in Part 1 that for final selection of CO₂ capture technology at a specific plant, a plant-specific techno-economic evaluation should be performed, also considering more practical considerations.

A technical evaluation of CO₂ capture technologies when retrofitted to a cement plant is performed. The investigated technologies are the oxyfuel process, the chilled ammonia process, membrane-assisted CO₂ liquefaction, and the calcium looping process with tail-end and integrated configurations. For comparison, absorption with monoethanolamine (MEA) is used as reference technology. The focus of the evaluation is on emission abatement, energy performance, and retrofitability. All the investigated technologies perform better than the reference both in terms of emission abatement and energy consumption. The equivalent CO₂ avoided are 73–90%, while it is 64% for MEA, considering the average EU-28 electricity mix. The specific primary energy consumption for CO₂ avoided is 1.63–4.07 MJ/kg CO₂, compared to 7.08 MJ/kg CO₂ for MEA. The calcium looping technologies have the highest emission abatement potential, while the oxyfuel process has the best energy performance. When it comes to retrofitability, the post-combustion technologies show significant advantages compared to the oxyfuel and to the integrated calcium looping technologies. Furthermore, the performance of the individual technologies shows strong dependencies on site-specific and plant-specific factors. Therefore, rather than identifying one single best technology, it is emphasized that CO₂ capture in the cement industry should be performed with a portfolio of capture technologies, where the preferred choice for each specific plant depends on local factors.

Cement production is a main source of carbon emissions. Decarbonization options exist, but their climate change mitigation potential, feasibility and environmental implications are still unclear. Here we assess 15 decarbonization options for the European cement industry under current and future conditions. Climate impacts per tonne of clinker produced today in European countries vary between 832 and 1,075 kg CO₂-equivalents. Decarbonization options at various maturity levels can mitigate between 7 and 135 Mt CO₂-equivalents per year (4–108% of today’s annual emissions from European cement plants), with a range of synergies and trade-offs. Solutions such as alternative fuels or technological improvements reduce climate impacts up to 30%, while a mix of ambitious complementary measures achieves a mitigation of about 50% by 2050. Only rapid and large-scale implementation of carbon capture and storage can approach climate neutrality. Carbon capture for production of e-fuels presents no significant mitigation benefits while it increases other environmental impacts.