A significant anaerobic digestion (AD) project has been given the green light in Kildare. Evergreen Agricultural Enterprises Ltd was granted planning permission for the AD plant located on a 20ac site near Monasterevin, Co Kildare. The plant will require 165,000t of feedstock per annum with the majority of this coming from Ireland’s distillery and brewery industry, in the form of spent grains. Spent grain is the material left over from malted barley after it’s been mashed to extract the protein, sugar, and nutrients.

While not particularly high in biogas yield, distillers’ and brewers’ grains are feedstocks already used in biogas production and animal feed. This development is set to play a significant role in the Irish drinks industry, so much so that global drinks manufacturer Diageo was linked to this development. The drinks company has since denied this.

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The plant will also use an amount of yeast and discarded beer, while 13% of the feedstock mix will come from maize silage, grass silage, and other whole crop silages. The plant won’t use any slurry or any material within a category two designation.

The plant will produce enough biomethane gas to supply 7,200 homes, most of which will be injected directly into the national gas grid. The plant will also produce CO2 gas and biofertiliser. It is estimated that around 145,000 tonnes of biofertiliser will be produced annually and exported to farms as a replacement for chemical fertiliser.