Divided solids -powders and granules- in reactive and non-reactive environments

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The proposed research regards the study of catalytically active particulate systems. A newly patented heterogeneous catalyst, using a zero-value metallurgical residue as active support, promises the development of new knowledge on catalysis mechanisms and the therefrom derived possibility of creating a new family of catalytic formulations for industrial applications. The intended research focuses on the following:***1. Development of a new family of heterogeneous catalysts: This work contributes into the development of new low-cost catalytic formulations applied both to already well known processes and to novel ones which would be used at industrial production level. The key-component in the proposed formulations is the Rio-Tinto-Fer & Titane mining residue (UpGraded Slug Oxide – UGSO); UGSO, as demonstrated in our previous work, can be used as the basis for the production of spinel structures; moreover, its components (mainly MgO/Al2O3/Fe2O3) can also be used as such or associated with other metals, mixed-oxides or oxides solutions in catalytic formulations. The previous works have shown that the Ni-UGSO catalyst can be used efficiently in any type of hydrocarbons and oxygenates reforming and partial oxidation. The proposed research targets oxidation and reduction reactions, both of which are important steps in environmentally and green chemical engineering-driven reactive systems.***2. Link catalytic activity with triple phase boundary: One of the missing elements in terms of mechanistic understanding of the role of nanomorphology in heterogeneous catalysis is the establishment of a link between the triple-phase-boundary (i.e. TPB) and catalytic activity. Besides the development of novel catalytic formulations, which could find industrial applications, the main scientific novelty resides in the adaptation of the FIB tomography/SEM imaging analysis to calculate directly the TPB length and relate it to the catalysts activity. The main challenge/novelty is to find the protocol allowing for sufficient image contrast and sampling over TOS without affecting catalysts integrity.***3. Multi-phase reactors design space definition and modeling: Multiphase reactors are typical examples of multi-step processes. They are characterized by in-series and parallel momentum, heat and mass transfer (both external and internal in the case of porous catalysts) and surface reaction resistances. Although models taking into account all these steps are desirable and yield nice-looking deterministic models, many assumptions must be made. The latter cannot be, usually, tested experimentally and consequently these models have only limited applicability. This research proposes the screening of variables allowing the definition of a design space where surface reaction becomes the controlling step. In that case modeling, both stochastic and phenomenological, becomes easier and more successful.