Analysis of different substrates for processing into biogas

Purpose: The main target is to produce as much biogas as possible with highest possible biomethane content from crops representing the principal fuel for driving the gas motors and electric generators and, consequently, production of electricity. Design/methodology/approach: The biogas production was measured by a mini digester according to the German standard DIN 38414, Part 8. It was effected in the mesophilic temperature range. The biogas production from six different energy crops and pig slurry was measured in the laboratory of the Faculty of Agriculture and Life Sciences. In six trial fields the monocultures such as maize, sorghum, amaranth, sunflower, Jerusalem artichoke and sugar beet were grown. Findings: The highest biomethane production was achieved with the sunflower substrate (283 Nl/kgVS), followed by the sorghum substrate (188 Nl/kgVS) and maize (187 Nl/kgVS). The amaranth substrate produced 225 Nl/kgVS and the Jerusalem artichoke 115 Nl/kgVS. The least amount of biomethane was produced from the sugar beet (95 Nl/kgVS). Research limitations/implications: The basic structure of the laboratory device is welded from stainless steel (inox) and is limited by the following dimensions: 2500 mm length, 1000 mm height and 350 mm width. The device consists of twelve units of fermentors ensuring four tests simultaneously with three replications and assuring high accuracy of results. Practical implications: The test fermentors serve to test the biogas production from different energy crops and other materials of organic origin. The results reached serve to plan the electricity production in the biogas production plant. Originality/value: The mini digesters simulated in laboratory the actual state from the biogas production plant. Anaerobic fermentation was introduced and the biogas to be processed into electricity was produced.