An experimental approach to the chemical properties and the ash melting behavior in agricultural biomass

Abstract

The present paper presents an experimental approach to the chemical and physical properties of the agricultural biomass from the point of view of the use of the biodegradable materials as fuel in incinerators at small and large scales. The wide variety of biomass sources implies a wide range of biomass fuel properties, both physically and chemically. Waste biomass could provide a significant part of the energy demand if appropriate conversion technologies are used. The types of agricultural biomass considered are corn, corn stalk, cereal mix, wheat, oatmeal, barley, corncob, rye, two-row barley, and corn and corncob mix. The study underlines the physical and chemical properties for analyzed materials. Using a statistical treatment to compare our set of data for different types of materials with the existing data from the literature, it can be noted that the net calorific values presented in this work are not statistically different from the mean value of the existing data in the literature. The net calorific values of the selected biomass ranged from 16,566 to 17,984 kJ kg−1 (dry basis). During the experiment, the flowing temperatures of the selected agricultural biomass were between 880 and 1480 °C. The flowing temperature values for the presented data are different than the mean values of data from references. So, the combustion facility allows the use of fuel from many local sources, thus making the control and minimization of the major part of the operational cost possible. The ash melting process is strongly influenced by its chemical composition, and it takes place in a wide temperature range. Therefore, the present work describes the characteristic points of the ash melting behavior. A complete proximate and ultimate laboratory analysis was conducted in order to determine the physical and chemical material characteristics [C, H, N, volatile matter, moisture, ash content, and gross and net calorific values (GCV and NCV, respectively)], the major and minor elements (Mg, Al, Si, P, S, Cl, K, Ca, Mn, Fe, Zn, Cr, Mn, Ni, Cu and Pb) and the ash melting points (SST, DT, HT and FT) for the analyzed materials that are further used in the combustion processes.