Anaerobic Digestion Plant - Teagasc Grange
A pilot-scale anaerobic digestion plant is currently under construction at Teagasc Grange. It is due to be commissioned in 2022. The plant will produce biogas using grass silage & cattle slurry. Find out more from our team in Grange Paul Crosson, Ciara Beausang, Sofia Tisocco & JJ Lenehan.
Anaerobic digestion (AD) is a multi-step process whereby organic waste and residues are converted into biogas by a group of microorganisms in an anaerobic environment. While biogas could be used as any of the three energy vectors, electricity, transport and heat. In Ireland it would be most useful if used for renewable heat or transport. Biogas refers to the gas prior to upgrading, which contains approximately 55% methane (CH4), while biomethane refers to the upgraded gas, containing approximately 97% CH4. Anaerobic digestion plants can be fed a wide range of organic feedstocks. There are many suitable feedstocks for biogas production from the agricultural sector, including crops such as maize specifically cultivated for biogas production, animal slurry and manures, as well as waste and by-products from agro-industries.
When fully-operational, expected nominal gas production will be 70 m3/hour. The bio-methane produced will be pressurised for transport by road tanker to the national gas grid at the injection point in Nurney, Co. Kildare. Alternatively, the bio-methane can be used for natural gas powered trucks with refuelling on site. In addition, the option of using a natural gas tractor on the research farm at Grange will be explored.
- The European Commission recently launched the REPowerEU plan which aims to diversify gas supplies, speed up the deployment of renewable gases and replace gas in heating and power generation.
- Biogas and biomethane are renewable energy sources which can be used in any of the three energy vectors, electricity, transport and heat.
- In Ireland, the anaerobic digestion (AD) sector is relatively underdeveloped despite a lot of studies indicating its potential due to the abundance of grassland and cattle slurry, which can used to provide feedstock for AD.
- Teagasc Grange is the site for a pilot-scale AD plant which is currently under construction and due to be commissioned in 2022.
- Research at Teagasc Grange is exploring the environmental and economic sustainability of biomethane from a range of grass silages derived from swards differing in species composition and in the rates of nitrogen fertiliser received.
- This research highlights that the fertiliser inputs and sward type used in silage production are key determinants in the sustainability of biogas production