Biogas production from small-scale anaerobic digestion plants on European farms

Small-scale anaerobic digestion (SSAD) is a promising technology for the treatment of livestock manure and the organic fraction of municipal wastes, especially in low population communities or in stand-alone waste treatment facilities. SSAD systems can transform organic matter into biogas (a mixture, mainly composed of carbon dioxide and methane), making the technology suitable for a variety of applications in energy, agriculture and, potentially, the emerging bio-products and bio-processes sector. Small-scale farming processes can further exploit the portable and flexible options made available by implementing SSAD systems to effect on-demand conversion of organic waste streams to useful heat (and, potentially, electricity), with significant economic benefits accruable (especially when such energy carriers are exported). SSAD is particularly applicable to the European agricultural sector, where the average individual farm sizes and land productivities are currently insufficient to meet the feedstock requirements of medium and large-scale plants. Despite the apparent benefits of SSAD, the technology is still not well utilised. Much of the research previously conducted has focused on large-scale systems. This study explores the current status of SSAD technology in Europe by identifying process design and operational characteristics, influential EU policies, the recent progress related to SSAD, and the issues encountered. The study sheds light on an area with limited research by providing an overview of the technology's present status in Europe by identifying areas of future study.