Interaction of mineral matter of coal with oxygen carriers in chemical-looping combustion (CLC)
Artikel i vetenskaplig tidskrift, 2014

The chemical-looping combustion (CLC) and chemical-looping with oxygen uncoupling (CLOU) processes are novel solutions for efficient combustion with direct separation of carbon dioxide. These processes use a metal oxide as an oxygen carrier to transfer oxygen from an air to a fuel reactor, where the fuel reacts with the solid oxygen carrier. When utilizing coal in CLC, the oxygen carrier particles could be affected through interaction with the ash-forming mineral matter found in coal, causing deactivation and/or agglomeration. In this work, possible interactions between minerals commonly encountered in coal and several promising oxygen carriers that are currently under investigation for their use in CLC are studied by both experiment and thermodynamic equilibrium calculations. Possible interaction was studied for both highly reducing and oxidizing conditions at 900 °C. Under highly reducing conditions pyrite was found to have by far the most deteriorating effect on the oxygen carrier particles, as the sulfur in the pyrite reacted with the oxygen carrier to form sulfides. Quartz and clay minerals were found to have a rather low influence on the oxygen carriers. Out of the oxygen carriers investigated, CuO/MgAl2O4 and the Mn3O4/ZrO2 oxygen carriers tended to be quite reactive towards mineral matter whereas ilmenite has been shown to be the most robust oxygen carrier. Although sulfur can clearly deactivate Ni, Cu and Mn based oxygen carriers under sub-stoichiometric conditions, when the fuel is converted fully to CO2 and H2O, sulfides are only expected for Ni-based oxygen carriers.

Oxygen carrier

Coal ash

CO2-capture

Ash transformation

Chemical-looping combustion (CLC)

Chemical-looping with oxygen uncoupling (CLOU)

Författare

Martin Keller

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Mehdi Arjmand

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Henrik Leion

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Tobias Mattisson

Chalmers, Energi och miljö, Energiteknik

Chemical Engineering Research and Design

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

Vol. 92 9 1753-1770

Styrkeområden

Energi

Ämneskategorier

Kemiteknik

DOI

10.1016/j.cherd.2013.12.006