Project Details
Projekt
Formulation of hetero-aggregates in continuously-operated opposed jet fluidized beds
Applicants
Professor Dr.-Ing. Andreas Bück; Dr. Jochen Schmidt
Subject Area
Mechanical Process Engineering
Term
since 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 462314498
The vision of the project is the establishment of a continuous process for formulation of ternary hetero-aggregates from dry primary particles. The functionality of the hetero-aggregates is grounded in the designed composition and distribution of hetero-contacts between constituents achieved by mixing at the primary particle scale (~ 25 nm). Process modelling is an integral part of the project: Firstly, to establish the process function of the formulation process (in the Rumpfian sense). Secondly, to generate tools for model-based sensor fusion, process optimization and control. Comprehensive characterization of hetero-aggregate properties links experiments and the simulation studies, iteratively providing validation and improvement of process models and experimental design as well as revealing the material functions of hetero-aggregate formulation in opposed jet fluidized beds. Having established the processing strategy, characterization methods, fundamental models of mixing of binary nanoscale primary particles into aggregates, and the connection between process parameters and structural parameters of the aggregates, the second funding period will see a continuation and extension of the focus towards functionality of the hetero-aggregates. The main designed functionality of the hetero-aggregates is photocatalytic activity by designing hetero-aggregate structures consisting of TiO2 and ZrO2 primary particles via composition and formation of hetero-junctions. Furthermore, a third component, bismuth vanadate, BiVO4, will be added to form ternary hetero-aggregates, extending the accessible range of the electromagnetic spectrum for “harvesting” electrons required in photocatalysis and to increase the efficiency of the separation of the generated electron-hole pairs, thus allowing design of an improved photocatalyst. The objectives of the project are: i) Establishment of a continuous ternary hetero-aggregate formulation process in opposed jet fluidized beds; elucidation of structure formation towards design functionality; ii) Development of a CFD-informed multivariate population balance model for formulation ternary hetero-aggregates; iii) Development of a model-based soft-sensor for photocatalytic activity of the hetero-aggregates, taking into account property and structure distributions (e.g., size, composition); iv) Model-based analysis, optimization and control of formation dynamics, structural properties and functionality by population balance models and soft-sensor; v) Extension of the SEM-EDX and the Raman mapping approach to characterize the intra- and inter-aggregate composition and mixing of ternary hetero-aggregates; vi) Elucidation of the optical, electronic and photochemical properties of ternary hetero-aggregates formed from semiconductors and characterization of the heterojunction (bulk behavior); vii) Linking of hetero-aggregates properties on the single aggregate level with bulk behavior and photocatalytic performance.
DFG Programme
Priority Programmes
