All of us are aware that we use wood as fuel but the truth remains the wood comprises a very less amount of carbon. In addition, it contains a major amount of impurities like sulphur, chlorine, silicon and water which decreases its efficiency as a fuel. Moreover, it also produces a large amount of smoke and ash. When the wood converts into charcoal by removal of volatile impurities and water, we gain an exceptional fuel with higher efficiency and low production of smoke. We note similar observations in biomass. When we use cow dung as fuel, a large amount of smoke and ash produces. Through this article, we will learn about biogas energy which generates from biomass by the method of anaerobic decomposition of organic matter.
Introduction to Biogas Energy
Biogas is a mixture of gases which the anaerobic decomposition of organic matter produces, for example, agricultural waste, plant residue, municipal waste, food waste and more. It comprises methane, carbon dioxide in conjunction with the small amount of hydrogen sulphide, and moisture.
The biogas plant comprises a dome-like structure. In this, the organic material like discarded food residue, fats, sludge, cow dung etc. mix with water and then fed into the digester through the inlet.
The digester is basically a sealed chamber where anaerobic decomposition of organic matter occurs. After a few days, the organic matter completely decomposes to produce gases like methane, carbon dioxide, hydrogen and hydrogen sulphide.
After that, we draw these gases through pipes from the storage tank above the digester and distribute through decentralization channels to neighbouring centres for use.
Biomass refers to any organic matter which we obtain from living or recently living organisms. For instance, crop residue, forest debris, animal waste, municipal solid waste and more. Further, it comprises 75% of carbon together with other molecules like hydrogen, oxygen, nitrogen. In addition, it also has a small number of alkali metals, alkaline earth metals, and heavy metals.
Advantages of Biogas
Biogas is very advantageous which we will study below:
1)Non-polluting: Biogas burns without smoke; therefore, it evolves no harmful gas such as CO2, CO, NO2, and SO2.
2)Reduces Landfills: The slurry which produces after the production of biogas, we can use it as manure in fields. The technique of disposal is safe and effective and henceforth, no space gets wasted in the form of landfills.
3)Inexpensive technology: A Biogas plant does not require an expensive installation cost and become self-sufficient within a time span of 3-4 months.
4)Creates employment: It also creates work opportunity for thousands of people, especially in rural areas.
5)Renewable source of energy: We consider it to be a renewable source of energy as the production depends on the production of waste which is an endless process.
Disadvantages of Biogas
In addition to having many advantages, there are also some disadvantages of biogas. They are as follows:
1)Inefficient on a large scale: As it is difficult to boost the efficiency of biogas, it is not economically feasible to use biogas on a large scale.
2)Contains impurities: It comprises a lot of impurities which are difficult to control even after putting it through many rounds of purification. When we compress biogas to use as fuel, it proves to be extremely corrosive to the container.
3)Unstable and hazardous: When methane comes in contact with oxygen it reacts violently to create carbon dioxide. As a result, the highly inflammable nature of methane makes it susceptible to explosions.
FAQ on Biogas Energy
Question 1: How does biogas energy work?
Answer 1: Biogas plants depend on anaerobic digestion. It is a fermentation process in which the microbes digest the waste for producing methane gas (biogas). We can convert the waste into bio-fertiliser and spread directly onto fields. Or we can use the biogas itself interchangeably with natural gas as fuel
Question 2: Is the biogas plant profitable?
Answer 2: Biogas plants are advantageous for agriculture, environment and consumers of heat and electricity. Undoubtedly, the biogas plant itself does not need the employment of a lot of staff. Nonetheless, the method of energy crops production can be a long-term source of income for numerous farms.
Question 3: What is the energy content of biogas?
Answer 3: A cubic metre of biogas contains on average a methane content of approximately 55% and consequently a calorific value of around 5.5 kWh.