Anaerobic Digestion (AD) A sustainable energy production

1. Anaerobic Digestion (AD) A sustainable energy production and waste management solution for your business Robert Crow 30 September 2014

2. Summary • Services offered to SMEs by Abertay University • Legislative drivers • Economic drivers • The science of AD • Feedstocks & pre- treatment • AD process outputs – Energy & Digestate • Factors to consider when installing AD systems

3. SBP – Abertay AD Expertise • Biochemical Methane Potential (BMP) assays • Feedstock analysis and pre-treatment • Reactor and pilot scale trials • Process development, design and optimisation • Bespoke training packages offered developed for operators and businesses new to the sector

4. Legislative drivers: Organic waste EU legislation Scottish legislation The Waste (Scotland) Regulations 2012 • All businesses in Scotland that produce over 50kg of food waste per week require this to be separated and uplifted to a permitted treatment facility • A ban on using on using macerators to discharge food waste into the public sewer is coming into force on the 1st of January 2016. • An energy opportunity exists since the biogas created from AD can be combusted within a CHP to generate a source of power and heat.

5. Economic Drivers • Landfill tax currently £80 per tonne of active waste • Add on the gate fee!! • Price of raw materials increasing – waste recovery and adding value is becoming necessary

8. Anaerobic Digestion – The science Source – Renewable Energy Concepts 2013

9. Feedstocks

10. Pre-Treatment of Feedstocks • Reduction of feedstock particle size • Feedstock blending • Feedstock containing grit or sand • Removal of packaging /pasteurisation Source – SLR consulting 2009

11. Feedstock assessment & process monitoring • Moisture Content (%) • Total Solids (%) / Volatile Solids (%) • pH • Volatile Fatty Acids (VFA) (mg/L HOAc) • Methane Yield (ml CH4 /g VS added) • C:N Ratio

12. Animal By-Products Enforcement (Scotland) Regulations 2011:Anaerobic Digestion • Implemented as a result of the 2001 Foot & Mouth disease outbreak and BSE crisis • Category 1 (cannot be treated by AD) • Category 2 (steam pre-treated unless manure or milk) • Category 3 (pasteurised before digestion)

14. Energy Utilisation Source SLR Consulting (2008)

15. End markets for AD digestate? • Horticulture • Agriculture • Brown field site restoration • Landfill daily cover http://www.wrap.org.uk/content/digestate-compost-agriculture PROCESSING REQUIREMENT INCREASING VALUE

16. PAS 110 Standard • Specification that allows digestate to be declassified as a waste • Physical tests • Chemical tests • Microbiological tests • Growth trials • Stability Tests

17. Key Issues developing AD systems • Initial feedstock assessment & feedstock supply • Process monitoring & measurement essential • Knowledge exchange between AD technology providers and operations staff • Engage SEPA at a early stage • Consult your local planning officer • End use of the biogas, heat and digestate should be considered

18. Any questions?