Silage of Switchgrass (Panicum virgatum) as a Bioenergy Feedstock in Poland

The production of biogas from the waste materials and crops is one of the main ways of acquiring the renewable energy. The switchgrass (Panicum virgatum) is a plant with significant potential for energy utilization in terms of thermal utilization and bio-logical processing. The aim of that work is to indicate the level of biogas productivity of switchgrass. The research methodology has been done according to DIN 38414 p.8. The plant material was used in the form of silage. The effect of exposure of plant material to atmospheric air was tested in the studies. Results were compared with silage samples. Plant substrate samples were mixed with biologically active liquid substrates: inoculum and slurry. Studies were carried out on the mixture with a dry matter content of up to 8% m/m. The results were statistically analysed. The correct courses of the fermentation processes were observed for both tested cases of the plant materials. Results of the studies indicated that the productivity of biogas for silage switchgrass, which was exposed to atmospheric air, was increased by 20.7% v/v. At the same time, increased emissions of nitrogen oxides and hydrogen sulphide were observed. The average methane concentration in biogas was higher for the aerated plant sample and was equal to 56.11% v/v. Favourable results for the initial method of aeration should be attributed to initiate decomposition of biomass be-fore the actual fermentation process.