Techno-Economic Analyses of the CaO/CaCO3 Post-Combustion CO₂ Capture From NGCC Power Plants

Calcium looping is a post-combustion technology that enables CO₂ capture from the flue
gases of industrial processes. While considerable studies have been performed at various
levels from fundamental reaction kinetics to the overall plant efficiency, research work on
techno-economic analyses of the calcium looping processes is quite limited, particularly for
the Natural Gas Combined Cycle (NGCC). Earlier work has shown that theoretically, a high
thermal efficiency can be obtained when integrating calcium looping in the NGCC using
advanced process configurations and a synthetic CaO sorbent. This paper presents an
investigation of calcium looping capture for the NGCC through a techno-economic study.
One simple and one advanced calcium looping processes for CO₂ capture from NGCC are
evaluated. Detailed sizing of non-conventional equipment such as the carbonator/calciner
and the solid-solid heat exchanger are performed for cost analyses. The study shows that
the CO₂ avoided cost is 86–95 €/tCO2, avoided, which is considerably more expensive
than the reference amine (MEA) capture system (49 €/tCO2, avoided). The calcium looping
processes considered have thus been found not to be competitive with the reference MEA
process for CO₂ capture from NGCC with the inputs assumed in this work. Significant
improvements would be required, for example, in terms of equipment capital cost, plant
efficiency and sorbent annual cost in order to be make the calcium looping technology
more attractive for capturing CO₂ from NGCC plants.

Keywords: calcium looping, CO₂ capture, sizing, techno-economic analysis, natural gas combined cycles