Fixed Dome plants
Fixed Dome plants were developed in China for processing of human waste. They were introduced in
Kenya in the 1970s but are not as widely installed as the Floating Drum types.
Its components are made using stones, bricks or concrete blocks with very few metal parts. They are
consequently cheaper to construct than the Floating Drum. The gas produced is stored in an
underground space just above the digester called the dome. As gas accumulates in the dome, it
displaces the sludge into a compensating tank. Gas pressure is not constant and when the volume is
low in the dome, gas supply will not reach the appliances.
Construction of dome-type plants has to be done very carefully otherwise slurry and gas leakages can
lead to poor performance.
Chapter Six
EXISTING BIOGAS APPLIANCES
Cookers
The most widely used biogas cooker is the model developed by Kenya Industrial Estates (KIE) - Special
Energy Programme (SEP) in 1986. It consists of a metal liner, a ceramic insert and a burner. A version
with a double burner is also available.
All the components of the burner can be produced in local workshops and this is the case with a
number of workshops in Meru. In Nandi District, CITC produces the burners from the centre's metal
workshop. The price ranges between US$ 14 and US$ 18 for the single burner and between US$ 27
and US$ 36 for the double burner version.
Lamps
Various organisations and individuals disseminate a lamp that was developed by KIE in 1987. There is
no special mantle for the lamp. It uses the one that is commonly used for the standard kerosene
pressure lamps.
Imported lamps are also available from some private companies. Shell Afrigas Company markets a
small size and large size biogas lamp imported from Brazil priced at US$ 34 and US$ 48.
The local KIE lamp costs between US$ 14 and US$ 18 depending on where it is purchased. The
efficiency of biogas lamps is low, between three and five per cent, although a good lamp can give light
equivalent to that produced by a 40-watt incandescent bulb.
Chapter Seven
DISSEMINATION OF BIOGAS TECHNOLOGY IN KENYA
Introduction
Since 1958 when biogas technology was introduced in the country, a number of government agencies,
Non-Governmental Organisations (NGOs), private companies and individuals have been involved in the
promotion and dissemination of the technology. The number of plants disseminated and installed by
1995 was estimated at 880.
Government Agencies
Special Energy Programme (SEP) - Kenya and collaborating partners