Biogas use in Reconstruction
Practical Action
Uses of Biogas
Biogas and the waste it is produced from have a wide variety of applications. They can be used in
household appliances or larger, community-based systems, providing energy services both
essential to everyday living in a reconstruction context and as a means of improving livelihoods
after a disaster. Some of the general uses include:
- Direct use for cooking, lighting and heating
- Fuel for combustion engines to drive an electricity generator
- Transport fuel
- Fertiliser (waste)
Some typical consumption rates for applications are given in Table 1 below:
Application
Consumption L/min
Gas lamp
2.4
Refrigerator burner
2.4
Domestic cooking burner
4-15
Commercial burner
20-50
Duel fuel engine (per kWh)
9
Spark ignition engine (per kWh) 11.5
Table 1: Typical consumption rates for biogas appliances (FAO, 1992).
Consumption m3/hour
0.14
0.14
0.2-0.9
1-3
0.56
0.7
Biogas Plants
Biogas plants are sealed containers built specifically to create the anaerobic conditions necessary
for digestion and controlled production of gas. Most common biogas plants must be fed daily with
feed material or slurry to ensure continuous gas production. The slurry is a mixture of organic
material and water, usually in equal proportions. Many types of organic materials can be used.
The aim of the digester is to provide a sealed vessel that allows input of feedstock and removal of
gas whilst being built of locally available construction materials.
Domestic Biogas Plants
The most common types of digester are the floating dome (or Indian digester), the fixed dome (or
Chinese digester) and the Sri Lankan digester. These plants are predominantly for use with cattle
and/or pig waste, requiring regular ‘feeding’ and daily maintenance.
The construction of these plants requires significant investment and planning, and they are
therefore not generally suited to emergency responses. The permanent reconstruction phase,
where families and individuals are building long-term housing solutions, gives the most
appropriate opportunity to consider these technologies.
Figure 1: Sections of domestic Biogas plant designs.
(A) Indian digester
(B) Chinese dome digester
(C) Sri Lankan digester
Source: Practical Action
A
2