The world’s first anaerobic digestion plant fed exclusively with chicken manure - Stream Bioenergy’s Tully Biogas Plant outside Ballymena, Northern Ireland - is gearing up for expansion.

The plant hit the headlines in 2017 when it first opened, processing 40,000t of poultry litter, made possible by using ammonia-stripping technology from Byosis.

The ammonia-stripping stage uses sulfuric acid and generates ammonium sulphate that can replace artificial nitrogen fertiliser.

The biogas produced by the plant is fed into two 1.5MW gas engines that generate electricity on site, which is then sold to the national grid.

The developer, Stream Bioenergy Ltd, has secured planning permission to extend the plant to increase throughput to 200,000t per year and will produce both electricity and biomethane for grid injection.


The plant will process 200,000t of feedstock per year. It is intended to process poultry manures as its main feedstock, but will also use additional wastes to help balance out variations in the manure.

The expansion at the site has commenced and, when operational, could produce enough biomethane to displace 3% of the natural gas imported to heat Northern Ireland homes and businesses. However, local gas grid constraints remain a challenge.

It is hoped the new phase of the plant will be operational in late 2026.