(358d) Application of the Law of Additive Reaction Times to the Analysis of Oxidation Kinetics In the Air Reactor of a Chemical Looping Combustion System

Chemical Looping Combustion (CLC) is one of the promising technologies for CO₂ capture which has the potential to reduce the energy penalty. A CLC system consists of two interconnected fluidized beds which act as a fuel and an air reactor, with a re-circulating metal/metal oxide system acting as the carrier of oxygen between the two beds.

Insights to the design and optimization of an air reactor in a CLC process could be obtained by analyzing the oxidation kinetics by the Law of Additive Reaction Times. The law offers an approximate closed form solution for a first order system in which structural changes on reaction can be neglected. It takes into account the pore diffusion of gaseous species in the interior of the porous pellet. The scenario is in contrast to the usage of shrinking-core models for porous solids, which assumes the occurrence of the reaction along a well-defined sharp reaction interface that progresses into the solid as the reaction occurs. This law provides a convenient and realistic means for analyzing air reactors in CLC systems for the oxidation process.

In this presentation, the results of applying The Law of Additive Reaction Times to the reported experimental data on the oxidation kinetics of copper in an air reactor of a CLC system will be discussed. It will also highlight the utility of a criterion provided by the law which helps in understanding the relative importance of chemical reaction, pore diffusion and external mass transfer that make up the overall reaction process.