Alkali interactions with a calcium manganite oxygen carrier used in chemical looping combustion
Journal article, 2022

Chemical-Looping Combustion (CLC) of biofuels is a promising technology for cost-efficient CO2 separation and can lead to negative CO2 emissions when combined with carbon capture and storage. A potential challenge in developing CLC technology is the effects of alkali metal-containing compounds released during fuel conversion. This study investigates the interactions between alkali and an oxygen carrier (OC), CaMn0.775Ti0.125Mg0.1O3-δ, to better understand the fate of alkali in CLC. A laboratory-scale fluidized bed reactor is operated at 800–900 °C in oxidizing, reducing and inert atmospheres to mimic CLC conditions. Alkali is fed to the reactor as aerosol KCl particles, and alkali in the exhaust is measured online with a surface ionization detector. The alkali concentration changes with gas environment, temperature, and alkali loading, and the concentration profile has excellent reproducibility over repeated redox cycles. Alkali-OC interactions are dominated by alkali uptake under most conditions, except for a release during OC reduction. Uptake is significant during stable reducing conditions, and is limited under oxidizing conditions. The total uptake during a redox cycle is favored by a high alkali loading, while the influence of temperature is weak. The implications for the understanding of alkali behavior in CLC and further development are discussed.

Surface ionization detector

Oxygen carrier

Chemical looping combustion

Alkali

Author

Viktor Andersson

University of Gothenburg

Amir H Soleimani Salim

Chalmers, Space, Earth and Environment, Energy Technology

Xiangrui Kong

University of Gothenburg

Henrik Leion

Chalmers, Chemistry and Chemical Engineering, Energy and Material

Tobias Mattisson

Chalmers, Space, Earth and Environment, Energy Technology

Jan B. C. Pettersson

University of Gothenburg

Fuel Processing Technology

0378-3820 (ISSN)

Vol. 227 107099

Förbränningskemi för biomassa med syrebärarmaterial

Swedish Research Council (VR) (2016-06023), 2017-01-01 -- 2024-12-31.

Subject Categories

Chemical Process Engineering

Other Chemical Engineering

Bioenergy

DOI

10.1016/j.fuproc.2021.107099

More information

Latest update

5/30/2022