Water Diffusion Modelling of CFB Fly Ash Thermoset Composite

Department of Chemical Engineering, University of the Philippines-Diliman, Quezon City 1101 Philippines

^a Corresponding author: ralph.villa@coe.upd.edu.ph

Abstract

The shift in coal-fired power plants from pulverized coal (PC) boiler technology into the greener circulating fluidized bed (CFB) boiler technology resulted into a major deviation in the properties of the waste fly ash generated making it less suitable for its previous application as additives for construction materials. A new market for CFB fly ash had to be found for it not to end up as a zero value by-product. Using CFB fly ash as filler for thermoset composites is a new and remarkable application. Only a few studies, however, have been done to characterize the properties of this new material. Further experimentation and analysis may be costly and time-consuming since common procedures are material destructive. A computer-aided modeling of the composite’s water sorption behavior was done. The effect of particle loading, size and shape were considered. These properties were varied and the resulting overall diffusivities were compared to previous experimental studies. The comparison of the model and experimental diffusivity values showed satisfactory results. This model may then provide a cheaper and more time-efficient method for the characterization of the water sorption properties of CFB fly ash thermoset composites. In the future, this may lead to further studies on its application as a green material.