1. Anaerobic digestion & markets for digestates David Tompkins Agriculture Sector Specialist

2. WRAP’s vision is a world without waste, where resources are used sustainably. We help businesses, individuals and communities reap the benefits of reducing waste, developing sustainable products and using resources in an efficient way. About WRAP

3. Focus on food waste Reduction and re-use of food and drink wastes 16Mt of post-farm gate food and drink waste 5.3 Mt of avoidable household food waste –Representing over 20 million tonnes of CO 2 e –3% of total UK GHG emissions –6% of total UK water footprint –1 in 4 cars on the road in the UK Ideally this waste would be prevented –Where this is not possible, it should be recycled –Composting offers one solution –AD offers another – with the advantage of renewable energy Main WRAP driver

4. Anaerobic digestion (AD)

6. Farm-fed Food-waste-fed Industrial processes http://biogas-info.co.uk/maps/index2.htm AD in the UK 107 operational facilities 44 farm-fed (manures, slurries, crops) 47 food-waste-fed (households) 16 industry-fed (distilleries, dairies) Total capacity ~5Mtpa ~ 230 more plants in planning

7. Classification by input: Manures and purpose-grown crops Waste-derived: –Source-segregated –Mixed Biosolids and co-digestates AD can be: Wet (<15% DM) or dry Mesophilic (35 - 40°C) or thermophilic (55 - 60°C) http://www.defra.gov.uk/publications /files/anaerobic-digestion-strat- action-plan.pdf Types of digestate

8. Most UK digestates are low dry matter (<10%) Can be separated –Fibre –Liquor Different fractions have different physical and chemical characteristics –Different potential uses Digestate is not just digestate…

9. Digestate regulations WRAP focusses on digestates derived from source- segregated wastes, including: –Food processing residues –Kitchen waste –Crop processing residues As soon as a waste is mixed with non-waste, the whole mix becomes a waste BUT… there is a way out of this [Digestates derived from manures and purpose- grown crops not normally regulated]

10. To transform ‘waste’ digestates into ‘products’ Two parts: –Anaerobic Digestate Quality Protocol –Approved specification (PAS110) If an operator complies with both and is independently certified to both, then the biofertiliser is no longer a waste and can be used as a product BUT, ADQP lists allowable markets www.biofertiliser.org.uk Digestate regulations

11. PAS110 specification includes limits on: E. coli and Salmonella PTEs (Cd, Cr, Cu, Hg, Ni, Pb, Zn) Digestate stability Physical contaminants PAS110 specification requires tests for: pH Total nutrients & ammonium-N Dry matter Digestate regulations

12. WRAP’s market development work >99% digestate is used in agriculture –Replicated field experiments across the UK –www.wrap.org.uk/dc-agri –Biofertiliser Matrix Other uses –Brownfield restoration and regeneration (particularly energy crops) –Soil manufacture –Turf establishment –Sports and amenity turf maintenance

13. As an ingredient in growing media As a liquid feed for containerised strawberry production In soil-less hydroponic trials Key questions: –Can digestate be used in these applications? –What are the constraints? –Can these be overcome? –Are there business benefits? –Should the ADQP be changed? Horticulture pre-feasibility trials

14. Thank you David.Tompkins@wrap.org.uk 01295 817896 07703 331947 www.wrap.org.uk