UnWRAPping the Mystery of Digestate Enhancement
Whipps, A., Pell Frischmann Consultants
(free)
Abstract To support the delivery of a number of actions contained in the AD Strategy and Action Plan (June 2011) and the delivery of Scotland’s Zero Waste Plan(2010) WRAP commissioned Pell Frischmann to undertake a review of digestate enhancement technologies.
This paper reviews the work completed under WRAP Contract OMK006-002. The study considered both non-waste and waste-based digestates, mixed-waste digestates as the output from Mechanical Biological Treatment, sludge digestates and co-digestates from feedstocks including sewage sludge.
The key aim of the study was to raise awareness in the UK Waste Sector to opportunities for enhancing digestates in advance of significant planned growth of anaerobic digestion facilities in the UK.
Key Words :Anaerobic Digestion, Digestate, Enhancement Technology, PAS 110, WRAP.
Introduction: The use of the anaerobic digestion process for the treatment of sewage sludge and generation of renewable energy, is well established in the UK. However, the use of anaerobic digestion for other organic wastes such as food waste is in its infancy and there is increased focus and reliance on this form of treatment. Currently the majority of digestion facilities recycle digestate to agricultural land as an organic fertiliser, but with limited application windows linked to crop and agricultural requirements, the demand for agricultural land will increase. WRAP has acknowledged the need to raise awareness of managing digestate as a resource and not simply a waste for disposal. The paper describes the background to the WRAP Contract OMK006-002(WRAP 2011), the key aims and objectives of the study, study methodology and approach adopted and the key findings.
