Hohenheim University Simulates the Operation of a Biogas Plant with Simulink and Simscape
“The model can be used to simulate a range of different biogas plant operation scenarios. Rather than just the outcome of a research project, it could be a good start for developing a complex concept for optimization of sector coupling.”
Key Outcomes
- Simulated annual energy output from a different daily feeding in only 15 minutes
- Tuned different parameters to simulate a wide range of biogas plant operational scenarios
- Achieved high simulation accuracy, with average errors not exceeding 7.7% when comparing simulations to real data
Simulation for biogas yield during anaerobic digestion, combustion of biogas in a CHP, electrical and thermal energy output, and distribution to consumers (above) and the research biogas plant Unterer Lindenhof (Germany) (below).
Located in Stuttgart, the University of Hohenheim is Germany’s leading university in agricultural research and food sciences. The university’s State Institute of Agricultural Engineering and Bioenergy facilitates an interface between university research and agricultural practice, with a focus on bioenergy production and network system services.
At the biogas station, a substrate mixture of manure, slurry, and energy crops—such as corn, cereals, grass, and sugar beet—is fed daily to digesters. In the digesters, a mixed bacterial community—which includes methanogenic archaea—degrades biomass and produces biogas. Desulphurized and dried biogas is supplied to combustion chambers of a combined heat and power (CHP) system. Electrical energy and heat are distributed on the farm for the needs of local facilities, and a surplus of electrical power is supplied to the grid.
The University of Hohenheim has a MathWorks Campus-Wide License, and MATLAB® tools were already being used to model continuous processes for biogas research. Recently, researchers selected Simulink® and Simscape™ for a funded project to model the coupling of a biorefinery and a biogas plant. The purpose of the simulation was to consider different scenarios of onsite heat distribution and assess potential heat output in the case of different substrate mixtures fed to the digesters.
Using MATLAB and Simulink, researchers developed a simulation flow model that calculates the biogas production rate, based on the substrate mixture, and prognosticates the electrical and thermal output of the CHP system. Different parameters can be tuned—including different substrate mixtures, settings of controllers, ambient temperature, pump flow rates, and number of consumers—to perform simulations under varying conditions of demand-driven energy production.
