Carbon capture by means of indirectly heated carbonate looping process (CARINA) : final report

The main scientific objective of the project was to achieve a technological proof-of-concept and a detailed economical evaluation for CO2 capture from coal-fired power plants with the indirectly heated carbonate looping process. A very innovative and scalable 300 kWth pilot plant was designed, erected and operated at Technische Universität Darmstadt to prove the application of heat pipes for the indirectly heated calciner. The main outcomes of the CARINA project are as follows: A suitable sorbent with high capacity, large availability and low attrition tendency was identified for experimental investigations in 300 kWth scale; Thermodynamic evaluations of different retrofit configurations of the indirectly heated carbonate looping process showed higher net electrical efficiencies compared to the standard carbonate looping and proved that a retrofit is feasable. The plant size can be significantly decreased with combustion air preheating, internal solid/solid heat exchange or an unheated second stage calciner; An economical assessment proved that the CO2 avoidance costs are 15 - 20 % lower compared to the standard carbonate looping process; More than 600 hours of plant operation with more around 400 hours of stable CO2 capture were performed in the worldwide first indirectly heated carbonate looping plant using high temperature heat pipes. High CO2 capture rates above 90 % have been achieved; A long-term heat pipe test for a large scale plant with a 6 m heat pipe was successfully performed for more than 1000 hours; A possible integration of the process into a power plant site was developed and evaluated.