(643e) Non-Isothermal Kinetic Studies of Carbon Dioxide Capturing On CaO-Based Sorbents

The increase of atmospheric carbon dioxide concentrations in recent years is well documented and potentially linked to an Earth wide greenhouse-like effect. This has led to tighter regulations on carbon dioxide emissions from various industrial sources. One of the most common discharge sources is the fossil fuel based energy production industry, which generates high temperature streams containing carbon dioxide at the exit of fossil fuel combustion processes.

Removal of carbon dioxide from high temperature water-air mixtures can be achieved using calcium-based sorbents. It has been experimentally shown in our prior work that CaO/Zr nanostructured sorbents possess a consistently high capacity to capture carbon dioxide over several high temperature carbonation/decarbonation cycles. In this work, we provide theoretical support for these experimental results by applying kinetic models that account not only for the transport and reaction effects, but also for the heat diffusion effects. Experimental data suggests a fast reaction thus generating a high rate of heat release that might result in a temperature gradient within the particles or between particle and the bulk fluid. We reformulate a model proposed by Wen and Wang (1970) to represent this particular system. The predictions of the resulting partial differential equation system are compared to TGA-obtained experimental data.