Exploring and harnessing the product development potential of selected uplands residual biomass for the benefit of a sustainable low carbon circular economy

Residual upland biomass left from different land management practices has little economic value. We are using selected technologies to explore product development to deliver economic and environmental benefits. In Baden Baden (Germany) these technologies are already exploiting urban green waste for the benefit of a low carbon circular economy. Our interest is in the potential for such an approach to enhance the resilience of communities in the Welsh uplands. The integrated generation of solid fuel and biogas from biomass (IFBB) processing procedure involves a hot water pre-treatment to encourage the release of sugars and corrosive metals, followed by a screw press mechanically separating the solid and liquid fraction. The enriched liquid fraction is fermented via anaerobic digestion, which is subsequently used to produce electricity. The remaining solid fraction is a press cake that can be used as solid fuel in domestic or industrial appliances or undergo additional processing to produce new products. During pyrolysis, biomass is burnt in the absence of oxygen to create biochar. Characterised by its porous structure, biochar can be further processed to create activated carbon used to adsorb impurities within e.g. water industries. In our most recent studies, a mobile pyrolysis retort was used to produce biochar from a range of residual biomass with and without IFBB pre-treatment. Selection of the best candidate biochar for steam activation and adsorption trials was based on the following criteria: biochar yield above 30%, organic carbon content above 50%, and ash value below 15%. Biochar derived directly from gorse, rhododendron, Molinia, rushes and bracken met the criteria, along with IFBB-treated press cake from Molinia, rushes and bracken. These biochars are currently being evaluated to test their suitability for use within the water industry, as well as their potential as slurry and soil additives.