Biogas | Terminologies | Uses | Importance

Biogas is a technology that is used to tap energy from biodegradable waste materials and it can be used as fuel for various uses by humans. Each and every day, high quantities of waste get thrown away just because maybe there isn't adequate know-how to turn those waste into something useful but this is the issue that biogas addresses. The technology makes use of waste materials which to some are useless into useful energy and we will be looking at some of these things extensively here. 

WHAT IS BIOGAS?

Biogas is a form of gas produced when organic materials(plant and animal products) are acted upon or broken down by bacteria in a process of digestion called anaerobic digestion. Anaerobic is a breaking down process in which the process of decomposition of organic materials by the actions of bacteria happens in the absence or oxygen. After the organic materials are broken down by bacteria, some chemical elements are released or disintegrated which are Methane, Hydrogen Sulphide, Carbon dioxide, water vapour and some other trace gases. Biogas contains about 70-85% Methane gas(CH4), Oxygen(O2), Carbon dioxide(CO2), Hydrogen Sulphide(H2s). Methane which comprises the largest component is the combustible gas that is used and the other trace gases can be purified to get rid of them in order to have a concentrated methane for high and effective performance.

Terminologies

Biomass: This refers to organic materials that can produce and some include cow dung, human waste, pig dung, fowl dropping, and agricultural or kitchen waste like vegetables, fruits etc. In a more defined term, everything that can be acted upon by bacteria that is fed into the biodigester is termed biomass.

Biofuels: Bio-energy obtained from the decomposition of biomass which are used to solve energy and its related challenges in society.

Biogas digester or biodigester: It refers to a system that breaks down biomass into biogas that can be stored and used. The digester is also the container that houses the food or fruits waste, cow dung etc to make sure the anaerobic digestion occurs to release biogas.

Storage: After the biogas is produced, it has to be stored in a container from which it is channeled to the kitchen for cooking, farm use and many more.

Uses of Biogas in the society

• For cooking: It is a very clean gas that can be connected to a kitchen stove or burner for cooking. This is one of the major uses of biogas for which households are adopting the technology because it provides reliable fuel which is clean and obtained at a very low cost. Imagine such a clean gas that you will not even buy but only produce from your own organic household waste, many love to enjoy the luxury of using biogas.

• Energy for farms: Some farms that are engineered by machines make use of the energy from biogas to power some of electric generators to operate such farms at a very low cost.
• It is used to power some home electrical appliances: Biogas is such that it can be converted to electrical form of energy to power home appliances. This way a sure and reliable energy source is available which means the headache of high electricity bills and unpredicted power outages is put under control.

With this idea of biogas production, there is a new toilet facility called bio-fill toilet or the biodigester toilet that is helping many households. This kind of toilet does not require too much space to construct and it helps to process the human waste into gas for cooking and it remains active and useful for a very long time. One advantage too is that it does not produce odour but it helps manage the waste well largely as compared to the methods formerly used.

A bio-digester toilet under construction

Importance of biogas

Biogas is a renewable source of fuel or energy

Biogas energy or fuel is every renewable which means that it does not run out or get finished once the digester is refilled with biomass for the process to continue. Many of the energy sources make use of non-renewable and them getting finished is a challenge sometimes but here is a very great alternative that can provide unlimited energy supply.

Biogas does not pose harm to the environment

Burning charcoal, firewood among others pose dangers to both the environment and humans but unlike biogas, it provides a clean energy that we cannot say poses harm to the environment. Burning or charcoal and firewood releases carbon into the atmosphere which we know contributes to global warming aside many health complications they pose to humans due to the smoke and even exposure to the heat.

Provides fertilizer for use on all kinds of farms

It is a fact that is totally undeniable that most of the food crops wee now consume in one or the other are contaminated with chemicals used in farming and this is due to the now prominent inorganic farming. Food scientists would say that food can be referred to as a medicine in itself but in a case where it has been contaminated with chemicals, then it is no longer the food that benefits the body that is being consumed but only what can satisfy human hunger. The slurry from the digester after the gas is produced is a very good organic fertilizer for our farms which contains no chemicals and this fertilizer too is cheap to access. There are now inventions and innovations that even convert the fertilizer from its liquid state to a form that it can be stored and transported to large-scale farms.

A means to a livelihood can be derived from it

There are a lot of families that spend a lot of the current energy forms they use and looking at the population in different countries, people who make up their minds to produce and supply rural and urban areas with this clean energy for both home and industrial uses can create some cool jobs for themselves. Creativity and good application of knowledge will help anyone who ventures into this area to be helpful to society as he or she also gets some honorable returns.

A great way to cut expenditure

To calculate the money spent on the acquisition of charcoal, firewood and even LPG by some households and companies within a short duration, it amounts to a lot as compared to biogas in which no amount is going to be spent on keeping the system run provided the waste materials are freely obtained. Indeed it is a sure way to cut on expenditure and plan for other needs.

I was opportune to watch some interviews of some people using biogas for cooking at home, in the farm and for other needs and they had nothing to say but positive and encouraging remarks about this amazing technology. If you are getting interested with what you are reading and want to put this into action, that is the energy and so we will look at how you can make a simple biogas to experiment in order to stand on it and build one for your domestic use.

Simple diagrammatic representation of a biogas plant

The materials needed include: a simple burner, gas tube, tube for gas storage, a gallon, valves etc. 

The container obtained must be air-tight and the lid has to be drilled for insertion of a valve and another hole as a point for feeding the digester with biomass. A valve has to be fixed on the gas collection tube and this valve should be such that it can allow gas into the tube and also be able to let out the gas inside the tube. Insert a valve on the lid of the digester and connect it with a gas tube to the gas collection tube. A gas tube must be used again to connect the valve in the gas collection tube to the burner. 

A very simple diagram showing a biogas digester, a gas collection tube and a gas burner in position.

Over here the container was fed with biomass, the biomass is acted upon by bacteria for some days after which the gas is produced and it moves for storage in the gas collection tube. A gas burner is shown with a flame here.

This video gives a labelling of the various parts of the diagram and also gives a quick demonstration of the whole process.