Biogas Production
Biogas is a renewable fuel that is produced when organic matter, such as manure and sewage sludge is broken down by microorganisms in the absence of oxygen. This process is called anaerobic digestion. For this to take place, the waste material needs to be enclosed in an environment called a dome where there is no oxygen.
Digestion carried out by these microorganisms creates methane, which can be used as it is locally or upgraded to biogas equivalent to natural gas quality, enabling the transport of the biogas over longer distances. Material containing organic nutrients is also produced in the process, and this can be utilized for purposes such as agriculture.
Stages in Biogas Production
Stage 1
Biowaste is crushed into smaller pieces and slurrified to prepare it for the anaerobic digestion process. Slurrifying means adding liquid to the biowaste to make it easier to process.
Stage 2
Microbes need warm conditions, so the biowaste is heated to around 37 °C.
Stage 3
The actual biogas production takes place through anaerobic digestion in large tanks for about three weeks.
Stage 4
In the final stage, the gas is purified (upgraded) by removing impurities and carbon dioxide.
Uses of Biogas
Cooking
There are biogas-specific stoves on the market that make the most of the fuel (House, 2011). One cubic metre of biogas can cook 3 meals for a family of 5 – 6
Lighting
Biogas is used to power gas lamps, which can be used both home and commercially.One cubic metre of biogas is equivalent to 60 –100 watt bulb for 6 hours
Electricity generation
One cubic metre of biogasCan generate 1.25 kilowatt hours of electricity
Heating
It can be used in instruments used for water heating, space (room) heating etc.
