Deslagging of Eichhornia crassipers and Pistia stratiotes biomass pellets

Abstract

Deslagging of Eichhornia crassipers and Pistia stratiotes biomass pellets was studied after dynamic or static addition of CaO, MgO or kaoline at 600 or 800 °C. Then the chemical element and crystal phase compositions of ashes were characterized by X-ray fluorescence and X-ray diffraction. The K and Cl concentrations declined by 10%–12% and 6%–8% respectively after the use of additives, and were both higher under dynamic addition than under static addition at the same temperature. The ashes contained some high-melting-point crystal phases (e.g. Ca3Si2O7, CaMgSi2O7), which can raise the melting temperature of ashes. By comparing the slagging indices between the two types of biomass ashes, we found the deslagging effect of static loading of additives was better than dynamic loading. The deslagging effect was optimized after the static loading of kaoline at 800 °C for both types of biomass. Under the condition that these research results are applied to thermal system of power plant, it can provide basis for solving slagging problem of biomass boiler.

Keywords

• Eichhornia crassipers pellets
• Pistia stratiotes pellets
• Biomass ash
• Additives
• Deslagging