Research Projects

Sean O’Connor

Current PhD Student

Small-Scale Anaerobic Digestion

Small-scale anaerobic digestion (SSAD) is an attractive technology for the treatment of livestock and organic fraction of municipal wastes. SSAD systems can transform organic matter into biogas (a mixture mainly composed of methane and carbon dioxide) making the technology suitable for a variety of applications in energy, agricultural and as a starting feedstock for emerging bio-products and processes. SSAD systems thus do not only provide the benefits of: improvement of on-site energy generation, upgrading and provision of a nutrient rich fertiliser from the digester effluents, reduction in pathogenic loads, and reductions in odour and greenhouse gas emissions as afforded by large scale systems, but could additionally provide economic benefits with its application with lesser organic loading sources and with regards to its portability and flexibility. SSAD is particularly applicable to the Irish agriculture sector where the average dairy herd size consists of approximately 80 cows in 2016. Despite the apparent benefits of SSAD the technology is still not well understood with much of the research previously conducted focused on large-scale systems. The aim of this PhD is to address the relatively high fixed costs associated with traditional anaerobic digestion systems by delivering a robust, modular, and cost-effective SSAD system suitable for the Irish agriculture sector. Subsequently, providing a compelling product to farmers as it reduces emissions, costs, and odours, while providing on-site energy and a high-quality fertiliser, which can in turn be used on farms ensuring the productivity and nutrient levels of the farm soils. This research is being carried out under the EU INTERREG funded Renewable Engine Project and works with an industry partner Organic Power.


• Environ Conference
• University of Strathclyde Images of Research
• IT Sligo Postgraduate Conference
• All Energy Exhibition and Conference


Organic Power