2. Context What is AD? AD Viability Dos and Donts Case study
Topics Considerations for putting a project together
3. Context www.methanogen.co.uk [email protected] The earth
is what we all have in common (Wendell Berry)
4. Long-lived digester design 450 years combined operation Many
running > 20 yrs Low parasitic energy Simple, user-friendly
5. Context & Drivers - Its time to act! Climate change:
Last year, we reached 400ppm CO2 in the atmosphere The era of cheap
energy is over global energy transition. Energy is NOT just your
lights and heat. It is food. Population growth: 2050 9BN? 11BN?
Population growth: 2050 9BN? 11BN? Increasing urbanisation: 1.4M
people/week (Bham) Population age. 2000 2BN children Prediction for
2100? Legal CO2 reduction targets
6. Energy Food So what can I do? Reduce (Efficiencies) Re-
THINK!Reuse Recycle Water THINK! (resilience)
7. UK Storms: We have no heating, no power, no hot food
www.methanogen.co.uk [email protected]
8. What is Anaerobic www.methanogen.co.uk [email protected]
Anaerobic Digestion? AD is
9. . a cow, not a tractor!
10. What is Anaerobic Digestion? Organic material* Heat
ANAEROBIC DIGESTER @ 40C Biogas H2S & other gases To CHP to
create renewable electricity OR To boiler, Aga, Rayburn, gas
ring(s) Digestate (Biofertiliser) Optional separation intoOptional
separation into soil conditioner & liquid fertiliser OR Spread
to land An enclosed vessel: heated, stirred (either by 60% CH4
& 40% CO2 An enclosed vessel: heated, stirred (either by gas
mixing or mechanical agitation) www.methanogen.co.uk
[email protected] Natures own biological decomposition by
micro-organisms in the absence of oxygen (anaerobic) It is a
natural process that breaks down organic material in an airless,
heated and mixed tank
11. Anaerobic Digestion Composting Degradation of organic
matter in the absence of oxygen (bacteria, archaea, protozoa that
do not need oxygen to grow anaerobes) Degradation of organic matter
in the presence of oxygen in air (bacteria/fungi need oxygen to
grow aerobes) Best way to treat all non-woody organic wastes Best
way to treat all woody organic wastes Requires heat (ideally)
Generates its own heat (exothermic) www.methanogen.co.uk
[email protected] Creates CO2 Creates CO2 Creates fertiliser
whose nutrients are more available to plants, as well as a soil
conditioner Creates a soil conditioner / fertiliser Creates biogas
which can be used to create electricity, heat or vehicle fuel
13. SimpleAD plant running on slurry Cow slurry in Gas for
cooking or heating farm house Liquid used on grass Fibre ploughed
in Thermal solar heated digester Biofertiliser Digester 40C An
enclosed vessel: heated, stirred (case studies used gas mixing)
Biogas 60% CH4 40% CO2 Feedstock: Gravity or auger fed Gas Holder
Liquid Fibre Storage Direct Use Heat/hot water Boiler: (digester
heating) Aga/Rayburn
14. AD plant with Combined Heat & Power (CHP) Digester 40C
Biogas Gas Holder CHP -Tends to need a lot more feedstock -More
complicated to run Electricity 60% CH4 40% CO2 Liquid Fibre Storage
Biofertiliser Heat Heat Anaerobic Digester Feedstock
15. Using the biogas fromAnaerobic Digestion
16. Case study Bus Bristol-Bath Courtesy of University of
Southampton: Dhivya, Alba & Leo-Paul
18. Farm Abattoir Food Processing The Food Production Process
Currently, there is waste at every stage of the process AD closes
the loop Nutrients must go back to land in a beneficial way
Fertiliser(nutrients)backtoland* Retail Restaurant & Home
Anaerobic DigesterEnergy from Biogas *Recycle NPK &
micronutrients as fertiliser *Pathogen/weed seed kill *Sequester
carbon *Improve soil structure
Fertiliser(nutrients)backtoland*
19. Why AD of slurries/manures? 1989 Clive Pughs Slurry System
1990 With Displacement of fossil fuels (both fertiliser and energy)
Reduction in carbon dioxide, ammonia, nitrous oxide and methane
losses to atmosphere greatly reduced GHG potential
www.methanogen.co.uk [email protected] 1989 Clive Pughs Slurry
System WRI (Murcott) Digester
20. Environmental Benefits of AD Returns micronutrients, water,
carbon, nitrogen to soil Reduction in carbon dioxide, nitrous oxide
and methane losses to atmosphere greatly reduce GHG potential
Offensive odours eliminated/reduced Kills many weed seeds/pathogens
Kills many weed seeds/pathogens Addition of humus improves the
physical properties of soil water holding capacity, aeration, water
soluble aggregates and increased crop production up to 20-30%
Reduction in BOD (80-95%) www.methanogen.co.uk
[email protected]
21. Improved slurry handling Less water use Fertiliser benefit
is not just NPK, but significant and essential trace elements
Fertiliser performance is superior; nutrients are more readily
available, particularly Nitrogen Digestate does not hinder clover
Farming Benefits of AD Digestate does not hinder clover growth like
synthetic fertilisers. Faster re-grazing healthier animals
Increased ley life Production of energy and fertiliser reduces
costs of food production, improves profitability and adds an income
stream to the farm www.methanogen.co.uk [email protected]