Post on 03-Aug-2020
Right Tech, Right Model Angela Bywater
UK & World Biogas Expo 2019
Environmental Biotechnology Network (EBNet)
• Follow on from the AD Network
• Concerned with engineered microbial systems for environmental protection, bioremediation and resource
recovery
• One of 6 Phase 2 BBSRC/EPSRC Funded Networks in Industrial Biotechnology and Bioenergy (NIBB)
• Academic funding to (a) help address industrial problems and (b) help translate lab to industry
• Free to join and many free events to address challenges in this sector
Right tech – what size is Micro AD?
.2m3 in a household? 2m3 in a community garden? 20m3 in a hotel/co-op?
Urban? Peri-urban? Rural?
Right tech – what size is Micro AD?
300m3 (300 cows) heating a manor house for 25 yrs?
1100m3 (650 cows + orgs.) running a 90kWe CHP?
Right model – (Fixed/Mobile) Hub & Pod The HUB and PoD concept
Source separated food waste collected from households is taken to a centralised processing facility (the HUB) where it is homogenised, blended and pasteurised to
ensure it is safe.
This could be an existing site such as a landfill where there are already facilities for waste handling and spare heat from CHP for pasteurising.
The pasteurised food waste is tankered to farms, the ‘points of digestion’ (PoD) where the material is used as feedstock for the digester.
The biogas is used to meet farm energy needs with any excess exported.
The digestate provides a valuable organic fertiliser with nutrients in the right proportions and can be used to replace mineral fertilisers.
Benefits of HUB and PoD Environmental
Nutrients are returned to farm land
Reduction in use of fossil fuels
Reduction in GHG emissions from landfill and farms
Decentralised power production (AD framework)
Economic
Farm digestion becomes economical leading to increased take-up
No requirement for centralised digestion results in lower capital costs to local government
Income from energy sales to farms gives a boost to the rural economy
Farm based digestion creates local employment opportunities in the rural community
Waste management companies have greater flexibility and opportunities for recycling food waste
back to agriculture at lower costs
Source: Prof Charles Banks, University of Southampton; A Bywater, RASE Review of Farm AD
Right model: Co-op/aggregate?
Small farms: gas piped to centralised upgrading
& gas grid injection facility (Wijster, Netherlands)
OR
Small farms: Slurry transported (vehicle/pipes) to
centralised AD CHP facilities. Aim to co-digest 80%
of municipal animal manure, with energy crops from
5% of the farmland to replace 20% of the fossil fuels
(Ringkobing-Skjern Municipality, Denmark)
Source: http://task37.ieabioenergy.com/case-stories.html
Slurry/biogas (from lagoon digesters) transported to
centralised AD/CHP, respectively. Operated as a
micro-grid, either in island mode or grid-connected.
(Parana, Brazil).
Combine with other renewables, eg solar?
And…..?
• Mix and match renewables: eg Canadian example solar/biogas
• Virtual pipelines to off-grid gas grids
• Biomethanisation (use electrolytic H2 produced using excess renewable energy in order to biologically raise the CH4 level in biogas to >90%