Industrial waste materials and naturally occurring minerals as inexpensive oxygen carriers for chemical looping combustion

Abstract

Chemical looping combustion offers a solution for CO2 separation without energy penalty by using a solid oxygen carrier to transfer the oxygen to the fuel, instead of air. In place of costly manufactured oxygen carrier materials, cheap, naturally occurring minerals and solid industrial waste materials with comparable compositions are needed. Such materials should have a sufficient reaction rate and oxygen transfer capacity, retain stable performance under a large number of consecutive reduction-oxidation cycles, and if possible would not require pre-treatment and activation. Two inexpensive iron containing minerals, a Fe-Mn-based mineral from Egypt and Attapulgite, a Fe-containing Mg-Al phyllosilicate mineral from Greece, as well as a Fe-Mn based solid industrial waste are investigated in this study. All the samples exhibited the ability to deliver their lattice oxygen to the fuel and to some extent regain it, in the presence of air, therefore they are considered candidate 'oxygen carriers' for CLC.