No abstract

This article presents strategies for the development and practical modelling of biogas processes under economy market conditions. Herewith, anaerobic digestion results out of practical tests in different scales (lab to pilot) and different substrate mixtures were taken into account. Two lab-scale reactors on the one hand and pilot-scale examinations of chosen substrate mixtures on the other hand led to workable conclusions such as mixture suitability for biogas production, gas amounts and technical demands for fullscale implementation under market economy conditions. A comparison of both laboratory and pilot system performance with a full-scale biogas system has been done; herewith, the suitability of the corresponding practical process upscaling simulation has been proven. On the basis of the results, calculations regarding the necessary full-scale fermenter sizes and the required substrate amounts as well as the disposable (reusable) fermentation residues were made. The conclusion of outputs on biogas technology particularly with regard to the demand-driven production of electricity (500 + 250 kW flexible) as a special request for energy from renewable sources is given. As a further result, a general outlook and estimation for the economical implementation on a common Baltic Sea region country basis have been developed.

In order to meet the goal of 50% renewables in the electrical energy mix till 2030 set by the German government the expansion must be continued. One of the biggest problems with the increasing share of renewable energy are the arising fluctuations. In this study it was investigated how the manageability of the biogas production from waste can be used to create a flexible production strategy in order to improve the reliability of a renewable energy supply. The current misbalances between energy demand and supply of wind turbines and PV systems are the basis for this new strategy. The simulation is based on a stand-alone 100% renewable energy supply of a model town with a population of 1,600 people. In order to investigate the impact of this new biogas management strategy using 100% renewable energy supply (including wind and solar energy) a simulation tool using MATLAB was designed. Furthermore, to receive preliminary real data regarding flexible biogas production tests were done with a plug-flow digester. Lastly, an economic analysis regarding the profitability was carried out. Simulations in this study have shown that using a flexible and demand adapted biogas management can reduce the required battery capacity by up to 60%. Nonetheless, the combination with feed-in management of wind and solar power has to be further investigated.