Method for Separation of Coal Conversion Products from Sorbents/Oxygen Carriers

This Phase II Small Business Innovation Research project targets the development of a technology for segregating fuelbased contaminants (char and ash) from oxygen carrier material in the context of chemical looping combustion application. In chemical looping, the wellmixed solids that flow from the fuel reactor consisting of char, ash, and oxygen carrier particles cannot be completely separated into their constituents before they enter the air reactor. The slip of carbon leads to char oxidation in the wrong reactor and poor carbon dioxide separation efficiency. An efficient method to separate char and ash from oxygen carrier material is critical for the deployment of chemical looping technology. The proposed project will develop a novel method for char/ash separation from oxygen carrier that is specifically tailored to chemical looping combustion and its unique constraints and process conditions. The proposed segregation system consists of a novel combination of methodologies that together provide very high segregation efficiency, even under the extreme conditions of chemical looping systems. Following successful demonstration in Phase I at the labscale, the Phase II project will involve a significant scaleup and will include realistic chemical looping operating conditions. The components in
the novel segregation system will be optimized through parametric evaluation of several process conditions. Following completion of testing, the conceptual level engineering design of a pilotscale system integrated within an actual chemical looping operating system will be prepared. Commercial Application and Other Benefits The proposed technology will facilitate the development of chemical looping technology which is a potentially attractive approach for carbon dioxide capture and emissions mitigation. Other potential applications exist such as: separation of volatile inorganic species from recycle char in gasification systems, in the separation of carbon from coalfired plant ash to generate pozzolanic material to replace cement in concrete; in the recovery of coal and valuable rare earth minerals from coal cleaning reject streams; and in postconsumer goods recycling/wastetoenergy based on fragmentation and separation. Key Words: Chemical looping, oxygen carrier, carbon dioxide capture, segregation, char, ash