As a fuel, biomass differs in its properties from fossil fuels and acquisition thereof for energy purposes is limited; hence, the ongoing search for new bioenergetically useful plants. The article presents the results of physical and chemical analyses of seven species of perennial grasses: tall wheatgrass, tall wheatgrass ‘Bamar’, brome grass, tall fescue ecotype, reed canary grass, giant miscanthus, and sorghum. The research involved technical and elemental analysis as well as analysis of the ash composition performed in order to determine their potential use for combustion process. The measurement results were compared with those obtained for hard coal and agricultural biomass, which is widely used in the energy industry. The results suggest that perennial grasses can successfully be combusted with similar performance to coal if burned in appropriate combustion installations.

No abstract

No abstract

The extrusion-cooking technique may be used to convert the common bean into functional food products. There is still insufficient information on the properties of extruded beans. The aim of this work was to investigate the effect of extrusioncooking conditions on the pasting properties of two cultivars of the common bean (Aura and Toska) available on the Polish market. The bean was extruded using a twin-screw extruder at variable screws speeds and different amounts of water were added directly to the barrel. The pasting properties of the obtained extrudates were measured using a Micro Visco-Amylo-Graph. The extruded beans revealed more stable viscosity characteristics than the unprocessed ones. The addition of increased amounts of water to the processed material raised the peak viscosity of both extruded bean varieties. A higher screws speed during bean processing resulted in a higher peak viscosity only in the case of the Aura cultivar. However, the decreasing value of the cold paste viscosity was observed at higher speeds. This may indicate the negative effect of the extruder's screws speed on the gel formation ability of the extruded bean. The results showed that the extrusion-cooking process reduced the retrogradation tendency of bean paste due to starch degradation occurring during processing. K e y w o r d s: common bean, extrusion-cooking, pasting properties

The aim of the study was to assess the potential of organic wastes from the agriculture and food industry as co-substrate for biogas production, on the basis of physical and chemical parameters analysis and biogas yield in the process of methane fermentation. The experimental material consisted of carrot pomace, kale by-products and maize silage. Methane fermentation was conducted in bioreactors equipped with an automatic control and measurement system. The study indicated correct physicochemical properties in terms of high content of dry organic matter and also correct C/N ratio. That was reflected in high biogas yields which amounted to, respectively, 558 N dm3kg−1VS−1for carrot pomace and kale by-products, and 526 N dm3kg−1VS−1for maize silage. The study showed that the intensity of biogas production was varied and depended on the composition of fermented mixtures. Methane fermentation of organic waste mixtures significantly increased the amount of biogas efficiency compared to the fermentation of individual substrates. The successful run of the experiment indicates that a mixture composed of carrot pomace and kale by-products is a good substrate for the production of biogas.