Irish quarry and construction materials operator Roadstone is seeking planning permission for a €50m anaerobic digestion (AD) plant at Killough Quarry, Tipperary, aiming to decarbonise quarry operations while enhancing operational efficiency.

The plant will feature 30 Norwegian-developed Antec plug-flow reactors, reducing digestion times from 50-60 days to nine and cutting footprint requirements. 

John Jones, CEO of Utopia, said: “It significantly speeds up biogas production and will reduce conventional digestion times from around 50-60 days to nine days, on a much smaller footprint.”

Feedstock will include 15,000t of chicken manure, 20,000t of cattle slurry, 60,000t of grass silage, 5,000t of maize silage, and 5,000t of pot ale and spent grain annually, sourced within 60km of the plant. Pre-processing via acoustic cavitation and ammonia stripping will enhance throughput and efficiency.

The facility will generate five co-products: liquid biomethane, liquid CO2, electricity, organic fertilisers, and water. Biomethane production is projected at 8,880,000 m³, producing 6,000 tonnes of bio-LNG annually. Electricity and heat will come from a solid oxide fuel cell rather than conventional CHP.

Pat Gibney, Roadstone planning officer, said: “The AD plant would play a key role in decarbonising the company’s operations… the biomethane gas produced from the plant would be used to replace diesel and liquid natural gas currently used in these operations.”

Community concerns include location, water safety, traffic, and odour. Roadstone has committed to sealed containment and groundwater monitoring. A planning decision is due 7 February 2026, with potential operations by 2029.

Explore full project details and planning updates in the complete article.

(Photo credits to Roadstone’s official website)