One of the elements of the Polish Energy Policy program is the development of renewable energy, including energy from biomass combustion. In Poland, the Green Block was built at the Połaniec Power Station fired with 100% biomass fuel. This solution is conducive not only to obtaining energy but also to improving environmental protection. During the combustion of biomass in a fluidized bed boiler, about 50 thousand tons of fly ash per year being a source of nutrients for plants, for example potassium salts, phosphorus, calcium, boron compounds, etc. was derived. The subject of the research were three types of ashes from biomass combustion containing 80% dendromass and 20% agromass. Agromas was made of straw, dried material or sliced palm nuts. The physical characteristics and chemical composition of three basic fly ash samples are presented. Due to the high fineness and thus dusting during spreading, it was found that there is no possibility of the direct use of fly ash from biomass combustion as an alkalizing agent for acidic soils. The lowest bulk density was demonstrated by samples of fly ash originating from the combustion of biomass containing 20% straw as agromass, while the poorest in potassium and phosphorus were ash samples obtained from the combustion of biomass containing 20% agromass in the form of palm kernel slate. As additional components, mineral acids as well as inorganic compounds, including industrial waste, were used to correct the chemical composition and to mineral fertilizer granulation. The number of introduced components was related to the postulated composition of the produced fertilizer. Examples of mineral fertilizers obtained, both simple and multicomponent fertilizers, are presented.

This paper deals with the effect of impeller shape on off-bottom particle suspension. On the basis of numerous suspension measurements, correlations are proposed for calculating the just-suspended impeller speed for a standard pitched four-blade turbine and three types of hydrofoil impellers produced by TECHMIX for several particle sizes and for a wide range of particle concentrations. The suspension efficiency of the tested impellers is compared with the efficiency of a standard pitched blade turbine on the basis of the power consumption required for off-bottom suspension of solid particles. It is shown that the standard pitched blade turbine needs highest power consumption, i.e. it exhibits less efficiency for particle suspension than hydrofoil impellers produced by TECHMIX.

This paper investigates the influence of surface effects on free transverse vibration of piezoelectric nanowires (NWs). The dynamic model of the NW is tackled using nonlocal Timoshenko beam theory. By implementing this theory with consideration of both non-local effect and surface effect under simply support boundary condition, the natural frequencies of the NW are calculated. Also, a closed form solution is obtained in order to calculate fundamental buckling voltage. Finally, the effect of small scale effect on residual surface tension and critical electric potential is explored. The results can help to design piezo-NW based instruments.