Anaerobic Digestion (AD) A sustainable energy production and waste management solution for your business Robert Crow 30 September 2014 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 SBP – Abertay AD Expertise • Biochemical Methane Potential (BMP) assays • Feedstock analysis and pretreatment • Reactor and pilot scale trials • Process development, design and optimisation • Bespoke training packages offered developed for operators and businesses new to the sector 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. 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 Anaerobic Digestion – The science Source – Renewable Energy Concepts 2013 Feedstocks Pre-Treatment of Feedstocks • Reduction of feedstock particle size • Feedstock blending • Feedstock containing grit or sand • Removal of packaging /pasteurisation Source – SLR consulting 2009 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 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 pretreated unless manure or milk) – Category 3 (pasteurised before digestion) Energy Utilisation Source SLR Consulting (2008) End markets for AD digestate? • Horticulture • Agriculture • Brown field site restoration • Landfill daily cover http://www.wrap.org.uk/conte nt/digestate-compostagriculture INCREASING VALUE PROCESSING REQUIREMENT PAS 110 Standard • Specification that allows digestate to be declassified as a waste – Physical tests – Chemical tests – Microbiological tests – Growth trials – Stability Tests 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 Any questions?