Wet fermentation process
Metener has designed and constructed over 10 full scale biogas plants based on traditionell wet fermentation process. This is suitable for high water content biomasses like sludge, biowaste, food industry and municipal waste. Also it is possible to add small amounts of dry biomasses like grass and maize to the process. It is possible to add pasteurization unit for this plant type and it is necessary for biomasses with hygienic risk.
Dry fermentation process
Metener has developed and patented batch digestion process for dry, slowly degradable biomasses like straw, grass and wood. Research and development has been done since 2005 in pilot scale and since 2015 in full scale digesters.
There are two reference plants in Finland, third will be running this year 2018 and produce biogas for cars. Several projects are under pre-design stage in Finland and in Asia.
- Heat. Biogas can be easily used in boilers. Gas burner can be installed to oil boiler.
- Combined heat and power (CHP). When electricity is needed, biogas is used in CHP unit, which produces 35-42% electricity and 43-50% heat.
- Traffic fuel. Biogas is upgraded and pressurized before filling to vehicles. Upgraded biogas is called also biomethane and it is like natural gas, although biogas is renewable energy! Biogas / natural gas car is also called CNG.
- Biogas can be transferred by pipeline or in bottles. If biogas utilization (like CHP) is not next to the biogas plant, biogas can be transferred to the utilization place by pipeline with no energy losses. Biogas can be also bottled but first it need to be upgraded and pressurized.
Metener has delivered several turnkey biogas plants in Finland. We have talented and educated team with expertice on automation, pipeworks and biogas equipment installations. Groundwork and construction we mainly buy from reliable subcontractors.
Outside Finland there are multiple options. With licensing agreement, we train customer to build biogas plants and we only deliver design documents, consultation during procurement and construction, automation package and plant commissioning. With our help and remote control every process (wet / dry / upgrading) is started up and biogas plant is ready for operation.