Concepts for utilization of biogas and biomethane

Biogas can be used in many ways. In the combined heat and power plant it supplies electricity and heat. If biogas is upgraded to biomethane, it can be fed into the natural gas grid or used as fuel for appropriately equipped vehicles. Finally, the components methane and carbon dioxide can also be used as materials. Fraunhofer IGB supports you in the realization of new utilization concepts.

Use of biomethane as fuel

Betankung
© Fraunhofer IGB / Frank Kleinbach

Due to its high net energy yield, biogas is the most important bioenergy source. Biogas, a mixture of energetically usable methane and carbon dioxide, is produced during the anaerobic fermentation of organic matter. In combination with combined heat and power generation, biogas production is considered a technology with a very high CO2 avoidance potential.

In the EtaMax project, Fraunhofer IGB has shown that biomethane can also be used in the mobility sector – as a fuel for suitably upgraded vehicles. In this project, easily fermentable wet biomass with a low lignocellulose content – in particular low-cost biowaste and residual algae biomass that does not compete with food production – was completely converted into biogas using a combined, modular process with maximum energy production, while at the same time closing all material cycles. The aim is to use the biomethane purified as a vehicle fuel to power CNG (compressed natural gas) vehicles.

Biogas has also been successfully upgraded to biomethane in Brazil and is now used as fuel for the company's own fleet of vehicles. In a project funded by the International Climate Initiative of the German Federal Ministry for the Environment, a plant was built here to process the digester gas (biogas) from the wastewater treatment plant in Franca, Brazil, to natural gas quality. 

Material use: production of basic chemicals from methane and carbon dioxide

Biogas, a mixture of methane and CO2, can be used as a substrate to produce basic chemicals or biopolymers such as polyhydroxy fatty acids. Methanotrophic, i.e. aerobic, microorganisms are used in the utilization of biogas.