Combined Manganese Oxides as Oxygen Carriers for Biomass Combustion – Ash Interactions

Publication date: Available online 10 July 2019Source: Chemical Engineering Research and DesignAuthor(s): Ivana Staničić, Viktor Andersson, Malin Hanning, Tobias Mattisson, Rainer Backman, Henrik LeionAbstractCarbon 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℃ 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 simul...
Source: Chemical Engineering Research and Design - Category: Chemistry Source Type: research