Efficient CO2 capture from lime plants: Techno-economic assessment of integrated concepts using indirectly heated carbonate looping technology

The quest to decarbonize the lime and cement industry is challenging because of the amount and the nature of the CO₂ emissions. The process emissions from calcination are unavoidable unless carbon capture is deployed. Nevertheless, the majority of the available carbon capture technologies are expensive and energy inefficient. The indirectly heated carbonate looping (IHCaL) process is a promising technology to capture CO₂ from the lime and cement production, featuring low penalties in terms of economics and energy utilization. Previous works have highlighted the potential of the IHCaL, but the optimization of the process has not been discussed in enough detail and techno-economic implications are not yet fully understood. Within this work, ten scenarios using IHCaL technology to capture CO₂ from a lime plant were simulated. Hereby, different process configurations, heat recovery strategies and fueling options were computed. The calculations for the capture facilities were performed with Aspen Plus® software and EBSILON®Professional was used to simulate the steam cycles. A techno-economic assessment was included as well, aided by the ECLIPSE software.

The results demonstrate that the selection of the fuel for the combustor not only affects the CO₂ balance and energy performance but is also an important cost driver —there were considerable economic advantages for the computed cases with middle-caloric solid recovered fuel (SRF). The analysis shows how the heat recovery strategy can be optimized to achieve tailored outcomes, such as reduced fuel requirement or increased power production. The specific primary energy consumption (from −0.3 to +2.5 MJ_LHV/t_CO2,av) and cost for CO₂ avoided (from −11 to +25 €/t_CO2,av) using SRF are considerably low, compared with other technologies for the same application. The sensitivity study revealed that the main parameters that impact the economics are the discount rate and the project life. The capture plants are more sensitive to parameter changes than the reference plant, and the plants using SRF are more sensitive than the lignite-fueled plants. The conclusions from this work open a new pathway of experimental research to validate key assumptions and enable the industrial deployment of IHCaL technology before 2030.