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EnergyDecentral, the leading exhibition for decentralized energy supply, 15-18 November 2022, held within the EuroTier livestock trade fair in Hanover, Germany, will be presenting complete solutions for anaerobic fermentation of biomass and biogas processing.
Numerous exhibitors will offer biogas owners commercial alternatives to the expiring Renewable Energy Act (EEG) in Germany, which offered operators a guaranteed price. Solutions showcased will enable the supply of electricity, heat and fuels while also moving towards greater independence from Russian gas supplies thanks to power-to-gas concepts.
"Currently, German biogas plants produce around 100 terawatt hours of gas annually. Ten percent of that is processed into biomethane and fed into the gas grid," explains Marcus Vagt, project manager of EnergyDecentral, DLG (German Agricultural Society).
"There is already a well-developed infrastructure, because the existing natural gas pipelines and storage facilities can be used immediately, without additional costs," explains Vagt. A rapid expansion of biogas plants could greatly reduce Europe's dependence on Russian gas,” concludes Vagt.
Biomethane
Biomethane can be used in many ways in the electricity, heat and fuel markets. Bio-CNG (Compressed Natural Gas) and Bio-LNG (Liquified Natural Gas) are expected to be a viable alternative to fossil fuels.
In addition to methane, raw biogas produced from biomass contains up to 40 percent carbon dioxide. Therefore, biogas must be processed before it can feed into the grid.
EnergyDecentral, organized by DLG, will present technologies and heat recovery systems for processing biogas. Many of these can be installed efficiently as turnkey solutions.
Current solutions include membrane technologies, amine scrubbing or pressure swing adsorption processes. However, optimised components such as biogas coolers, gas compressors, heat exchangers and activated carbon filters in combination represent promising systems that offer minimal installation effort. Once treated, the biomethane can be fed into the gas grid or further compressed or liquefied to replace fossil fuel.
New processes include systems that convert carbon dioxide directly into methane. Smaller biogas plants can be a CO2 source without having to integrate complicated gas treatment.
Power-to-gas concepts
Power-to-gas means the conversion of electricity surpluses into a storable, gaseous energy carrier -useful in times of low wind and sunshine- and used as fuel or chemical material. The concept, which uses biogas or wastewater treatment plant as a CO2 source for methanation, is suitable for large biomethane plants. As there is no need to feed into the grid, effort and costs are reduced, offering existing biogas plants a flexible retrofit solution.
Researchers from the Brandenburg University of Technology (BTU) and Flensburg University of Applied Sciences will show how ‘sector coupling’ works at the Nissen Biogas company, which operates a 900-kilowatt biogas plant, two satellite combined heat and power plants (400 kilowatts each), a local heating network and two wind turbines with 0.6 and 1.5 megawatts of rated electrical output respectively.
The wind turbines will supply the electricity for an electrolyser that breaks down water into oxygen and hydrogen. The plant will supply raw biogas in which the CO2 content reacts with the hydrogen in a reactor to form methane. The conversion takes place through biological methanisation in a patented trickle bed process. The use of raw biogas as input favours the coupling with the biogas plant. The nutrient supply of microorganisms is possible, carried out in a trickle bed over the liquid fermentation residues of the biogas plant. The decoupled reaction heat is available for use for fermenter heating or a local heating network.
July 6, 2022 - DLG
