Transcript Anaerobic Digestion (AD) - Scottish Biofuel Programme

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