biogas policies
Introductory Paper
© copyright 2009 by Jeffrey Gale Designer of Eco-Architecture, Permaculture Woodland Gardens, Cyclic Energy & Waste Systems
SMALL-SCALE LOCALISED BIOGAS PLANTS: POLICIES
click HERE to view diagrams and notes
click HERE to download printable versions of diagrams and notes
click HERE to download this page (text only) as a .doc file.
I believe localisation of energy production can be made economically feasible by building low-cost Biogas Plants to my designs.
Small- and medium-scale Biogas Plants have been developed and widely built for many years throughout India, China, South Africa and Australia, but little used in Europe, especially Britain. This is largely because ambient temperatures were considered too low, and little research seems to have been done here about smaller scale plants.
However, with my designs the temperature of the slurry in the main digestion tank is kept up consistently at 20º – 30ºC by a looped water pipe heated by hot water from a boiler with a burner fed by methane from the plant. Also, the main rectangular digestion tank is insulated all around by 450mm recycled insulation, and fermentation is self-heating.
High efficiency of this plant means that about 60% methane and 38% CO2 can be used directly via a small buffer gas store to fire a large gas engine to dive a turbine producing continuous electrical power.
These plants can be built in new housing projects, sized appropriately. One medium-scale plant, served by a good P-H balance of kitchen wastes, lawn mowings and human toilet wastes (see note 1), can provide enough electricity and gas for up to 30 homes, as well as excellent organic compost and water effluent for use on gardens or allotments, or sold for neighbours and farmers locally. Fresh lawn mowings have one of the highest yields of methane gas of all organic wastes!
The decomposing of any organic wastes where air is present produces a majority of CO2 with little methane. So all landfills, compost heaps, septic tanks and most sewage works emit vast quantities of CO2 into our biosphere.
Meteorologists and cosmic scientists say that methane emissions are doing far more damage to our biosphere than CO2. Clearly there is also a huge opportunity now to lessen global warming and provide a highly efficient pollution free abundant source of decentralised energy for local communities in any part of the UK.
Unlike wind or solar power, Biogas does not rely on the whims of the weather, as it is completely reliable any season of the year. If these plants became widespread, they would also give a continuous supply of organic compost to boost organic farming, horticulture and gardening. The compost from my designs is semi dry and recoverable from lift out perforated metal trays, allowing water to gravitate to filter beds below. (Aerobic process.)
Windfarms and nuclear power are not the complete answer to our energy problems as these are inefficient and environmentally degrading.
More technical details:
The long rectangular shape of the main anaerobic tank enables maximum breakdown of solids into gases and compost. It is very important to continuously take off the gases and use the separated methane as outlined above, rather than storing it. The main function of the small storage cylinder in my designs is that of a pressure regulator. Certain pressures must be regulated to drive an electricity generator, gas boiler or cooker unit.
Where local WCs are connected to the plant, they must be flushed by warm water controlled by 1 litre flushing valves. The 100mm plastic standard soil drains must be insulated where WCs are situated more than 5 metres from the plant, otherwise the warmth will be lost. However, the heating pipe loop in the digestion tank will usually compensate for heat losses, and fermentation itself produces heat. Temperature is kept constant at 20º – 30ºC.
The plant can be built by local craftsmen and is not technically very difficult as long as the design criteria are kept to. It is very important to line the main tank with bitumenised or siliconised waterproof rendering which is also gasproof, but not under great pressure as gas is continuously taken off.
A PVA cover with tailored pipe and access trap outlets may be sealed to the large heavy duty polythene sheet covering the whole digestion tank top under the precast concrete planks structural cover, overlapping the side walls. It is crucial that this tank is water and air tight.
Some useful statistics:
Typical methane production (cubic metres per tonne) (see note 2):
For best microbe breakdown, water content in the main tank should not exceed 30%.
If you would like further information, please telephone me, Jeffrey, on 01803 868744 or email me at jeffrey@worldpeacegardensnet.org.
Copies of my designs can be posted to you if you wish to build a Plant to my designs.
Building of this plant is welcome, but pilot projects must be under my supervision.
These designs are copyright © Jeffrey Gale 2009.
Some interesting facts (see note 3) about a recently built North Devon Farming Cooperative Biogas Plant:
This larger scale Biogas Plant’s output of methane fuels a 2MW powerplant using 120,000 tonnes of animal and agricultural waste per annum from 27 local farmers. The plant generates 14.4 million KWh electricity per annum and 15 million KWh of heating to the local community per annum.
It also produces excellent fertiliser for these farmers, saving them each £7000 per annum!
By not releasing methane and CO2 into the atmosphere, it saves the equivalent of around 59000 tonnes per annum CO2 being released. Methane is about 20 times more damaging to the biosphere than CO2!
Notes:
(1) Only biodegradable cleaners must be used and 1 litre warm water flushing valve.
(2) Information source - A Chinese Biogas Manual, by Michael Crook, ITDG Publications Ltd., London
(3) website www.holsworthybiogas.co.uk, tel 01409 254888
This document updated 29.05.09
click HERE to download the above document in Word format (.doc)
read more about Permaculture Design:
Introductory Paper
© copyright 2009 by Jeffrey Gale Designer of Eco-Architecture, Permaculture Woodland Gardens, Cyclic Energy & Waste Systems
SMALL-SCALE LOCALISED BIOGAS PLANTS: POLICIES
click HERE to view diagrams and notes
click HERE to download printable versions of diagrams and notes
click HERE to download this page (text only) as a .doc file.
I believe localisation of energy production can be made economically feasible by building low-cost Biogas Plants to my designs.
Small- and medium-scale Biogas Plants have been developed and widely built for many years throughout India, China, South Africa and Australia, but little used in Europe, especially Britain. This is largely because ambient temperatures were considered too low, and little research seems to have been done here about smaller scale plants.
However, with my designs the temperature of the slurry in the main digestion tank is kept up consistently at 20º – 30ºC by a looped water pipe heated by hot water from a boiler with a burner fed by methane from the plant. Also, the main rectangular digestion tank is insulated all around by 450mm recycled insulation, and fermentation is self-heating.
High efficiency of this plant means that about 60% methane and 38% CO2 can be used directly via a small buffer gas store to fire a large gas engine to dive a turbine producing continuous electrical power.
These plants can be built in new housing projects, sized appropriately. One medium-scale plant, served by a good P-H balance of kitchen wastes, lawn mowings and human toilet wastes (see note 1), can provide enough electricity and gas for up to 30 homes, as well as excellent organic compost and water effluent for use on gardens or allotments, or sold for neighbours and farmers locally. Fresh lawn mowings have one of the highest yields of methane gas of all organic wastes!
The decomposing of any organic wastes where air is present produces a majority of CO2 with little methane. So all landfills, compost heaps, septic tanks and most sewage works emit vast quantities of CO2 into our biosphere.
Meteorologists and cosmic scientists say that methane emissions are doing far more damage to our biosphere than CO2. Clearly there is also a huge opportunity now to lessen global warming and provide a highly efficient pollution free abundant source of decentralised energy for local communities in any part of the UK.
Unlike wind or solar power, Biogas does not rely on the whims of the weather, as it is completely reliable any season of the year. If these plants became widespread, they would also give a continuous supply of organic compost to boost organic farming, horticulture and gardening. The compost from my designs is semi dry and recoverable from lift out perforated metal trays, allowing water to gravitate to filter beds below. (Aerobic process.)
Windfarms and nuclear power are not the complete answer to our energy problems as these are inefficient and environmentally degrading.
More technical details:
The long rectangular shape of the main anaerobic tank enables maximum breakdown of solids into gases and compost. It is very important to continuously take off the gases and use the separated methane as outlined above, rather than storing it. The main function of the small storage cylinder in my designs is that of a pressure regulator. Certain pressures must be regulated to drive an electricity generator, gas boiler or cooker unit.
Where local WCs are connected to the plant, they must be flushed by warm water controlled by 1 litre flushing valves. The 100mm plastic standard soil drains must be insulated where WCs are situated more than 5 metres from the plant, otherwise the warmth will be lost. However, the heating pipe loop in the digestion tank will usually compensate for heat losses, and fermentation itself produces heat. Temperature is kept constant at 20º – 30ºC.
The plant can be built by local craftsmen and is not technically very difficult as long as the design criteria are kept to. It is very important to line the main tank with bitumenised or siliconised waterproof rendering which is also gasproof, but not under great pressure as gas is continuously taken off.
A PVA cover with tailored pipe and access trap outlets may be sealed to the large heavy duty polythene sheet covering the whole digestion tank top under the precast concrete planks structural cover, overlapping the side walls. It is crucial that this tank is water and air tight.
Some useful statistics:
Typical methane production (cubic metres per tonne) (see note 2):
fresh grass mowings (semi-dry) 630
cattle & horse manure(semi-dry) 400
straw* (semi-dry) 240
leaves from trees* (semi-dry) 260
sunflower leaves* (semi-dry) 300
human toilet inputs (sludge) 400
green garden and vegetable wastes* (semi-dry) 500
(* – these items need to be processed in the electric shredder before entry)
For best microbe breakdown, water content in the main tank should not exceed 30%.
If you would like further information, please telephone me, Jeffrey, on 01803 868744 or email me at jeffrey@worldpeacegardensnet.org.
Copies of my designs can be posted to you if you wish to build a Plant to my designs.
Building of this plant is welcome, but pilot projects must be under my supervision.
These designs are copyright © Jeffrey Gale 2009.
Some interesting facts (see note 3) about a recently built North Devon Farming Cooperative Biogas Plant:
This larger scale Biogas Plant’s output of methane fuels a 2MW powerplant using 120,000 tonnes of animal and agricultural waste per annum from 27 local farmers. The plant generates 14.4 million KWh electricity per annum and 15 million KWh of heating to the local community per annum.
It also produces excellent fertiliser for these farmers, saving them each £7000 per annum!
By not releasing methane and CO2 into the atmosphere, it saves the equivalent of around 59000 tonnes per annum CO2 being released. Methane is about 20 times more damaging to the biosphere than CO2!
Notes:
(1) Only biodegradable cleaners must be used and 1 litre warm water flushing valve.
(2) Information source - A Chinese Biogas Manual, by Michael Crook, ITDG Publications Ltd., London
(3) website www.holsworthybiogas.co.uk, tel 01409 254888
This document updated 29.05.09
click HERE to download the above document in Word format (.doc)
read more about Permaculture Design: