Solar Technology Laboratory
Towards Solar Fuels - Physico-chemical Contributions to the Development of Solar Reactors. Mathematical modelling of solar-chemical reactions |
| Contact: Anton Meier |
| Running Time: 01. January 2000 - 31. December 2001 |
|
Funding: Swiss Federal Office of Energy |
DescriptionThe mathematical modelling of solar-chemical reactions includes fluid dynamics, matter diffusion, heat conduction, chemical reactions, and interaction of matter with light. Since solar-chemical processes are usually operated far from equilibrium it is important to consider irreversibilities. Thermodynamics of irreversible processes is a framework for a unified description of all these topics. The main open theoretical problem is to include electromagnetic radiation and its interaction with matter in the frame of thermodynamics of irreversible processes in order to obtain a general scheme for the description of solar-chemical processes. This scheme is then applied to solar-chemical processes of practical interest. As a first item, stationary radiative ablation of a ZnO rod is modelled. The model includes conservation of matter and energy, heat conduction, chemical decomposition with a reaction rate equation of Arrhenius type (no back reaction), radiative flow in the solid, interaction of light with matter by volumetric absorption and thermal emission. The radiation field is described with the two-flux model (Kubelka-Munk theory). Spatial variations are considered only in one dimension (infinite slab). |