Scale up planned for a new CO2-capture process

Plans are underway to field-test a process that removes more than 90 % of the carbon dioxide from power-plant flue gas, while reducing both the energy input and operating costs by 50 % compared to conventional amine-based CO2-scrubbing technology. The so-called carbonate-looping process has undergone four years of testing in a 1 MWth pilot plant at the Technical University of Darmstadt (Germany; www.tu-darmstadt.de). Now, with support from the German Federal Economics Ministry and industrial partners, a new project has started to scale up the process 20-fold, and to demonstrate the technology in an existing (yet-to-be determined) coal-fired power plant in Germany. In the carbonate-looping process (flow sheet), filtered flue gas enters a carbonator reactor — a fluidized-bed reactor — in which lime (CaO) reacts with the CO2 from flue gas at 650°C to form calcium carbonate. The CaCO3 is separated in a cyclone from the decarbonized fluegas, then calcined at 900°C in a second fluidized-bed reactor, the calciner, to release the CO2 and regenerate CaO for reinjection into the carbonator. The captured CO2 is then cooled (with heat recovery) and filtered to produce a pure CO2stream that can be utilized or stored. Since…