A simplified intensification process has been developed called Dune that utilizes back-mixing of dried digested sludge cake with fresh wet cake using natural biological processes within the mixture to generate heat for drying. Dune provides key opportunities to reduce transport cost, to maximize use of limited land bank whilst recycling nutrients, to address post-digestion methane emissions and to support the bioresources sector in enabling for advanced thermal processes. By providing aeration to maintain aerobic conditions within the mass of the mixed materials, temperatures rapidly rise, and moisture is removed. The result is a well stabilized soil type product, reduced in weight by approximately 50% which significantly reduces transportation costs.

The Dune process has been successfully demonstrated at field scale at three completed trials at THP solids processing facilities (Oakland County, Michigan, US and Dŵr Cymru Welsh Water, UK and DC Water, US). The paper will present results and discuss how lessons learned will be applied in the integration of Dune within the Ofwat Innovation Pyroplas project, led by Severn Trent Water and one of three Round 5 Transform Fund winners. The paper will present GHG monitoring and discuss challenges and opportunities for the technology in supporting sustainable bioresources futures.