Modelling the gasification of carbon fibres Original Research Article

A quantitative model describing the changes undergone by a carbon fibre during gasification (porosity, surface area, pore volume, fibre diameter, reactivity, losses of carbon by percolation, etc.) is presented. In the approach adopted, the porous network of a carbonized fibre is described by a random pore model, which takes into account different reaction regimes (chemical and diffusional control) and structural solid properties (initial porosity and critical porosity). The phenomenon of disintegration of the solid into fine fragments when the porosity of the carbonaceous matrix reaches a critical value (percolative fragmentation) is included in the analysis presented here. The results of the simulation include the variation of local properties (gas concentration, porosity and surface area) within the fibre at different reaction stages as well as the modification of the overall fibre properties (reaction rate, porosity, surface area, fibre size and percolated mass fraction) with reaction progress.