Kovács, P. G. (2008). Ways of achieving competitive gaseous transportation fuel (biomethane) production through anaerobic fermentation of selected energy plants grown in Hungary [Diploma Thesis, Technische Universität Wien]. reposiTUm. https://resolver.obvsg.at/urn:nbn:at:at-ubtuw:1-30979
The purpose of the master thesis is to elaborate the conditions and measures for achieving the future competitiveness of biomethane (biogas upgraded to natural gas quality) with natural gas for use as environmentally clean transportation fuel (biofuel) in Hungary. Several key factors are directly related to the feasibility of producing biogas for vehicle fuel application: the selection of energy crops, the intensification of the biogas fermentation technology and the efficiency of biogas upgrading technologies. The work has identified the most promising energy plants for biogas production under Hungarian climatic conditions; these are (in the sequence of prospectivity): cup plant, sweet sorghum, Jerusalem artichoke leaves. Upon reviewing the different ways of fermentation technology improvements it could be concluded that the application of thermophilic process temperature together with the use of a Hungarian biotechnological-microbiological innovation offers the best solution for achieving the highest digestion rates in the most efficient manner. This method is based upon scientific engineering the bacteria consortium through introducing selected hydrogen producing bacteria into the system. The biogas upgrading technologies are quickly developing and more and more technical solutions are offered. The evaluation of the available technologies leads to a clear conclusion, that at present the low pressure amine absorption is the best choice. The collected data on energy crops and technologies have been incorporated into a wide range feasibility study, which analysed 15 different versions. It was concluded, that the feasibility of biomethane production under Hungarian conditions could be achieved in 3-5 years through the combination of - operating the biogas fermentation at thermophilic temperatures, - applying the biotechnological innovation discovered and patented by Hungarian scientists, - applying the most up-to-date and proved biogas upgrading technology (low pressure absorption on amine-complex), - growing and processing high yield energy plants with excellent biodegradability (such as sweet sorghum and cup plant) and - building a unit of substantial size (1.000 m3 biomethane/hour). In order to reach the target, the scientific research and development activity has to be continued and completed in every related field.