CO2 capture with CaO in a 200 kWth dual fluidized bed pilot plant

The Calcium Looping (CaL) process using CaO as sorbent for capturing CO2 from flue gases is a promising postcombustion CO2-capture technology that is economically competitive with other capture technologies with an overall increased output in electric power and a low electric efficiency penalty associated with CO2 capture. The process can be realized in a Dual Fluidized Bed (DFB) system utilizing a Circulating Fluidized Bed (CFB) reactor as carbonator operating at 600–700 °C and a second CFB as regenerator operating at temperatures between 850–950 °C. The separation of CO2 from the flue gas takes place through the carbonation reaction (CaO+CO2→CaCO3). The regeneration of the sorbent is realized via the reverse reaction in the regenerator at higher temperatures.The feasibility of the CaL process has already been shown at IFK, University of Stuttgart on a lab-scale size. In order to investigate the calcium looping process using real combustion flue gas and to evaluate the process on a long-term basis, a 200 kWth pilot plant has been built at IFK. This paper delineates the design of the pilot plant to capture over 90% CO2 and provides an overview of the main components and the control philosophy. First results from the successful commissioning of the pilot plant are also shown.