Combined manganese oxides as oxygen carriers for biomass combustion — Ash interactions
Journal article, 2019

Carbon capture and storage (CCS) has been acknowledged as an important strategy for mitigation of climate change. Although highly applicable for fossil fuels, CCS with biomass could have the added advantage of resulting in negative emissions of carbon dioxide. One promising carbon capture technology is chemical-looping combustion (CLC). In CLC the reactors are filled with metal oxide bed material called oxygen carriers. Before CLC can be implemented for biomass combustion at a large scale, biomass ash components interaction with oxygen carriers needs to be further understood. Four combined manganese oxides Mn3O4-SiO2, Mn3O4-SiO2-TiO2, Mn3O4-Fe2O3 and Mn3O4-Fe2O3-Al2O3 were exposed to common biomass ash components K, Ca and P. The ash components can exist in many forms, but here the compounds CaCO3, K2CO3 and CaHPO4 were used. Exposures were performed at 900 °C for six hours in oxidising, reducing and inert conditions. Crystalline phases were analysed by XRD and morphology examined with SEM-EDX. Results show that oxygen carrier particles containing silicon were more likely to form agglomerates, especially in combination with potassium, whereas the particles including iron were more stable. MnFeAl was the oxygen carrier that showed least agglomerating behaviour while simultaneously showing a propensity to absorb some ash components. Some inconsistencies between thermodynamic predictions and experimental results is observed. This may be explained by lack of relevant data in the used databases, were only a few of the oxygen carrier-ash systems and subsystems have been optimised. Further optimisation related to manganese rich systems should be performed to obtain reliable results.

Ash interactions

Fluidised bed combustion

Oxygen carrier

Combined manganese oxides

Chemical looping combustion (CLC)

Author

Ivana Stanicic

Chalmers, Space, Earth and Environment, Energy Technology

Viktor Andersson

University of Gothenburg

Malin Hanning

Chalmers, Space, Earth and Environment, Energy Technology

Tobias Mattisson

Chalmers, Space, Earth and Environment, Energy Technology

R. Backman

Umeå University

Henrik Leion

Chalmers, Chemistry and Chemical Engineering, Energy and Material

Chemical Engineering Research and Design

0263-8762 (ISSN) 1744-3563 (eISSN)

Vol. 149 104-120

Subject Categories

Chemical Process Engineering

Bioenergy

Metallurgy and Metallic Materials

DOI

10.1016/j.cherd.2019.07.004

More information

Latest update

6/17/2020