The occurrence of inorganic elements in various biofuels and its effect on ash chemistry and behavior and use in combustion products

The focus of this paper is to discuss the occurrence and effect of the inorganic composition of selected biofuels and their impact on ash behavior and ash utilization in combustion systems. Biofuels studied include: grasses, manures, and wood. A series of fuel blends were studied as to their possible ash composition and behavior during combustion at various temperatures. The fuels were subjected to chemical fractionation. The bulk chemical analysis and chemical fractionation data were input into a thermodynamic model, i.e., FactSage, to predict the chemical composition and amount of melt phases that form as a function of temperature. The amount and composition of the melt phase was then used as input into a program developed at Pennsylvania State University to predict viscosity of the melt phase. The resulting cofired ash was also evaluated for its suitability as an additive in concrete. (C) 2007 Elsevier B.V. All rights reserved.