2018 - Sustainable Industrial Processing Summit & Exhibition
4-7 November 2018, Rio Othon Palace, Rio De Janeiro, Brazil
| Carbon Capture in Molten Salts - Calcium Looping in the Molten State Espen Olsen1; Nils Rusås Ruud1; Heidi S. Nygård1; 1NORWEGIAN UNIVERSITY OF LIFE SCIENCES, Ås, Norway; PAPER: 325/Molten/Regular (Oral) SCHEDULED: 14:50/Tue./Bossa (150/3rd) ABSTRACT: Carbon Capture in Molten Salts (CCMS) is a method for extracting CO<sub>2</sub> from a variety of flue gases related to power generation and industrial processes [1-3]. It is based on a well known principle called calcium looping, where CaO reacts with CO<sub>2</sub>, forming CaCO<sub>3</sub> in a reactor chamber at temperatures well below 900°C. By moving the formed carbonate to another chamber and raising the temperature above 900°C, CaCO<sub>3</sub> decomposes - driving CO<sub>2</sub> off in a controlled manner reforming CaO. Solid sorbents may be moved between chambers by applying fluidized bed principles. In CCMS, the active chemicals are present as dissolved or partly dissolved in an inorganic molten salt. The salt is frequently based on CaCl<sub>2</sub>, with additions such as CaF<sub>2</sub> or NaF to suit specific needs with regards to capture efficiency, handling, and costs. In this paper we report on the most recent developments in CCMS technology as well as the economical aspects of using this method for capturing carbon from industrial flue gases. By dissolving and suspending the CaO and CaCO<sub>3</sub> in a molten salt, very rapid reaction kinetics are experienced due to catalytic properties exhibited by the molten salts. This is evidenced by activity coefficients for CaO and CaCO<sub>3</sub> being substantially above unity. This enables more efficient absorption than in systems based on sorption in the solid state. References: [1] E. Olsen and V. Tomkute, Energy Science & Engineering, 2013. 1(3): p. 144-150. [2] V. Tomkute, A. Solheim, and E. Olsen, Energy & Fuels, 2014. 28(8): p. 5345-5353. [3] E. Olsen, M. Hansen and H.S. Nygård, AIMS Energy, 5,(6), 2017, p. 873-886. |
