SCARLET has taken a significant step towards maturity and commercialization of one of the most promising CO2 capture technologies. Demonstrating the process in 1 MWth scale at realistic operating conditions, developing and validating various scale-up tools resulting in the comprehensive design and engineering of 20 MWth pilot plant prepared the ground for taking the next steps in pre-commercial demonstration of the technology. SCARLET is in line with the demand of rapid development of post-combustion CO2 capture technologies addressed in the European Union’s Strategic Energy Technology (SET) Plan. The technology investigated in the SCARLET project helps to fulfil the objectives of the European Union demanding for reduced costs and energy penalties of CO2 capture technologies. SCARLET has acquired the following innovative contributions:

  • Long-term operation of a 1 MWth pilot scale calcium carbonate looping CO2 removal system achieving high performance at high operability (various fuels, solid material, operating parameters etc.)

  • Development of various validated simulation models and criteria for the scale-up to the next road map step of 20 MWth equivalent size

  • Design and engineering of a 20 MWth pilot plant including operating procedures, health, safety and risk analyses showing no unmanageable risks as well as a calculation of investment and operational costs preparing the basis for pre-commercialisation of the CCL technology

  • Integration of CCL in commercial oriented power plants, in a steel plant or in a cement plant to optimize performance and minimize technical risks, targeting efficiency, reliability and operability

  • Economic assessment of CCL giving credibility to the technology of lower costs of CO2 capture within the target values established by the European Union

  • Environmental assessment confirmed its environmental credentials as compared to conventional CO2 capture techniques.

The project has strengthened the position of Europe as the key driver of the CCL technology. In particular, the long-term demonstration of the CCL process at 1 MWth scale under realistic operating was a milestone in the development of this technology. The application of this technology for power production will preserve and create jobs in the European market concerning technology development and energy supply, as well as by the cement and steel industry. The practical commercial application of its results, with the primary objective of fighting climate change and protecting the environment, will also support the European economy. Especially the export of CCL technology to countries worldwide relying on fossil based power generation and demanding for CCS technologies will be a great chance. The lead for the realization of this purpose is taken by European entities, thereof two major power companies as well as cement and steel companies in the consortium. The benefits seen in the CCL process by the consortium are multiple: two of the most important are the lower cost of CO2 avoidance and additional power generation of a retrofitted power plant with respect to other capture processes.

A main target addressed in the project was the long-term operation in 1 MWth scale under realistic operating conditions, such as realistic flue gas and oxy-combustion in the calciner. The variation of the type of fuel (hard coal, lignite in various particle size distributions), the sorbent, flue gas composition, reactor design, reactor temperatures, make-up flow, solids circulation flow etc. were used to obtain reliable data about the process performance in order to scale-up the process. Noteworthy to be mentioned is the fuel flexibility of the fluidized bed calciner, given for the operation of a retrofitted CCL plant for power plants. The process is suitable for a wide range of coal, proven by the pilot tests. As a consequence, the technology provides the option of feeding a wide range of fuels to the process, e.g. local European coals, biomasses or alternative fuels like refuse derived fuel. Therefore, the CCL technology would reduce the dependency on fuel imports and provides an additional application for biomass co-combustion and utilization of waste.

SCARLET brings CCL technology to the next level of maturity, preparing the ground for pre-commercial demonstration of this promising technology. The results give confidence for investments into a larger-scale 20 MWth unit facilitating the design of a future large-scale demonstration project, aiming at short term commercialization of the process. The cost estimate provides a sound basis to start a discussion between the various stakeholders (universities and research institutes, industrial partners and funding organizations) on how to finance and realize this essential next technology development step. The health and safety risk assessment as well as technical risk analysis done identified potential risks, allowed to develop related mitigation plans and thus increased confidence level for realization of the 20 MWth pilot plant. The further implementation of the results shall lead to the construction of the planned 20 MWth pilot in collaboration with a power plant owner or other industrial partner in a follow-up project. The proposed 20 MWth scale pilot plant will be an important step towards commercialization of the technology.

The economic assessment is of great concern comparing the technology to other CCS processes. The criteria developed by the European Benchmarking Taskforce were applied for the thermodynamic and economic evaluation of the CCL technology for various host power and industrial plants. The results for power plant retrofits show a significant reduction of the energy penalty to 6-7 %-points, lower CO2 avoidance costs in a range of 20-27 € per tonne of CO2 (MEA/oxyfuel 40-70 €) and a smaller increase of costs of electricity (CoE) of 20-40% compared to 1st generation capture technologies. A significant advantage is the fact that the CCL technology repowers existing power plants by recovering the heat generated in the CCL process by an additional highly efficient water/steam cycle. In contrary to other technologies where the power output is significantly decreased, additional power is added to the grid to cover additional power demand in Europe by a carbon clean technology.

Of particular interest is the application of the CCL technology in industrial processes like steel or cement production. Industrial installations are generally smaller in size compared to power plant applications. Therefore smaller size designs retrieved during the development of the large scale power plant CCL technology are already transferable into industrial solutions. Existing infrastructure and other process equipment in terms of cement application can be used, thus minimizing the expenditures for the total installation. Additionally, purged sorbent of CCL application can be utilized in industrial processes. Analyses carried out in the course of the project, show promising results for reutilization in the cement/clinker manufacturing process. The CO2 avoidance cost around 43 € per tonne of CO2 show significant technical and economic advantages of these synergies.