Germany-headed biogas specialist Weltec Biopower GmbH has disclosed that it is currently building a biomethane plant for the Irish company Evergreen Agricultural Enterprises Ltd that will go into operation in mid-2026.
Located at the company’s headquarters in Monasterevin, County Kildare, it will go into operation in mid-2026, after a total construction period of 11 months.
The location offers the operator logistical advantages.
On the one hand, it is well connected to the M7 motorway. In addition, the national gas network for direct biomethane feed-in is in the immediate vicinity, said Patrick Meade, Managing Director of Evergreen.
Process beer and whiskey production residues
The EUR 50 million project comprises four digesters and a single stainless-steel secondary digester, each with a volume of 4,900 m3.
These are mainly used to ferment production residues and by-products from the Irish beer and whiskey industry.
The decision not to use grass silage was a conscious one, so that we would not be competing with the livestock industry, Patrick Meade said.
The materials are readily available and do not compete with feed production, as they are unsuitable for animal feed.
Three additional tanks are used to store liquid substrates. A combined heat and power plant (CHP) installed on site generates around 1 MW of power for the operation of the plant and supplies heat for the digesters.
Despite its size, the plant, with an annual processing capacity of 165,000 tonnes, will be built in just six months of pure construction time. Construction is proceeding according to plan, and mechanical completion is scheduled for the end of this year, said Tobias Gerweler, Managing Director of Weltec Biopower.
Gas-to-grid
Three rotating long-axis agitators and three submersible motor agitators in the tanks support the effective digestion of the substrate mix.
The raw biogas will be collected in the digesters with double-membrane roofs and upgraded into biomethane – aka renewable natural gas (RNG) – using membrane technology.
The RNG will then be injected into the national gas grid 20 metres away via the feed-in point.
Once commissioned, the Monasterevin plant will produce approximately 1,300 Nm3 of RNG per hour, equivalent to around 110 GWh of energy per annum.
The annual output of 65,000 tonnes of digestate will be stored in a covered concrete lagoon and delivered to farmers separately as liquid and solid fractions.
Aligned with the national RNG expansion target
The Monasterevin project will also help Ireland to achieve its ambitious expansion targets for biomethane production – the government aims to produce 5.7 TWh of biomethane annually by 2030.
To achieve this target, existing biogas plants for biomethane processing would need to be expanded, and additional technically mature plants such as the one being built by Evergreen in Kildare would have to be planned and constructed.
The fact that German manufacturer Weltec Biopower was awarded the contract to build the largest plant in Ireland to date was due not only to the technical advantages mentioned above, but also to the short delivery times, concluded Patrick Meade.
