- advantages
easy construction and
very reliable, easy
low cost of construction,
operation, uniform gas
construction and
long useful life, well-in
pressure, mature
operation, uniform gas sulated
technology
pressure, long useful
life, mature technology
- drawbacks
metal gasholder can rust expensive
sealing of gasholder,
fluc tuating gas pressure
- All biogas plants require careful, regular inspection/monitoring of their gas-containing components -
Operation and
simple and easy; regular simple and easy; regular easy after careful
maintenance
painting of metal gas-
painting of metal gas-
familiarization
holder
holder
Daily gas-output
0.3-0.6
0.3-0.6
0.2-0.5
(m³ gas/m³ Vd)
(depends on substrate composition; here: cattle dung)
Cost elements
metal gasholder, digester metal gasholder,
combined digester/
digester
gasholder, Excavation
Comparison factor
100
120 60-90
Recommended uses
fully developed, reliable like floating-drum, plus inexpensive equipment,
family size system
longer useful life and
good for agroresidue,
operational reliability
extensive building
(incl. operation with
experience required
night soil)
Suitability for
+
++ +
dissemination
++ highly recommended, + recommended with certain reservations
balloon-type
Earth pit
Ferrocement
Horizontal (shallow)
continuous-feed,
continuous-feed, mixed continuous-feed, mixed continuous-ffeed,
fermentation channel
digester
digester
fermentation channel
integrated digester/gas-
earth pit as digester,
ferrocement digester,
masonry digester,
holder made of plastic
plastic gasholder
gasholder made of
floating metal gasholder
sheeting
metal or ferrocement
(or separate)
animal excrements only
animal excrements only animal excrements, with animal excrements, with
or without vegetable
or without vegetable
waste
waste
2-5 years
2-5 years
6-10 years
8-12 years
4-100 m³
4-500 m³
4-20 m³
20-150 m³
prefab. construction, easy extremely inexpensive,
potentially inexpensive shallowness, easy
operation
easy operation
construction, long useful operation
life, easy operation,
reliable
in-site processing and
same as with plastic gas ferrocement
expensive, metal
short useful life (2-5 years) holder, plus soil perme- construction not yet
gasholder tested
of plastic material, low gas ability
adequately time
pressure
easy; regular control of
easy
simple and easy
simple and easy
gas-pressure weights
0.3-0.8
0.1-0.5
0.3-0.6
0.3-0.7
plastic sheeting
plastic sheeting
concrete (cement),
digester, metal
lathing
gasholder
20-110
20-40
70-90
90
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