Interactive porous particles

Consumable" chemical interactions are all those in which a chemical reaction involves a solid phase that transforms into a fluid phase and/or another solid phase. There are many such interactions at industrial level. Examples include the regeneration of solid catalysts, the reactive dissolution of a solid, and numerous transformation operations in the mineral and steel industries.

At the level of the solid particle, the consumable interaction cannot be analyzed by a single model. In general literature, there are several types of model suitable for interactions, but these can be grouped into two main families, namely:

• the family of models with constant reaction volume and transfer properties ;

• the family of models with variable reaction volume and/or transfer properties.

For the first family, modeling the particle's evolution is representative of real quantities, and fine metrology can be used to validate the temperature and composition profiles observed within the particle.

For the second family, the aim of modeling is to best represent the macroscopic evolution of the particle. The underlying simplifications of the models do not generally enable the composition and temperature profiles within the particle to be represented as accurately as possible. On the other hand, the rate of transformation of the solid reactant is well estimated.

In this dossier, we present the analyses relating to these two families.

Once we've described the models, we'll apply one of them to the combustion of a coal particle.