Biogas: everything you need to know about this energy source

Typologies and future prospects of this form of renewable energy

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By Max Bender


The search for alternative energy sources is full on, and scientists are always coming up with new opportunities for development. They are also utilizing previous untapped energy sources, including biogas. But what are we talking about exactly? What are the pros and cons of this resource?

The prospect of biogas is therefore an interesting one which has many implications.

Let’s see what this biogas actually is. Biogas is a mixture of various types of gas (mostly methane), obtained from the fermentation of animal or organic vegetable sources, industrial waste, agro- industrial waste, etc. This gas is formed in the absence of oxygen.

When this waste is decomposed by bacteria, a quantity of carbon dioxide, hydrogen and methane is discharged. All of these gases can be used for power generation through appropriate boilers, or they can also be used directly as a fuel.

It is easy to guess that the best potential “reserves” of biogas are the urban waste landfills. A large part of  waste landfills consists of organic components,  and the waste from intensive farming, which accumulate large amounts of animal manure and other waste.

Biogas can easily be used as fuel for vehicles. Car that are equipped with methane utilizing technology have already been developed in Europe. Utilization of biogas can be the gateway to a possibility of more eco -friendly travel.

The great advantage of biogas is that it minimizes CO2 emissions. Another environmental benefit is that during the production of biogas, methane gas is trapped. During their natural decomposition organic waste produces large amount of methane, which is harmful to the environment.

Finally, biogas seems particularly adequate to promote growth in the agricultural sector. A country taking the lead in the technologies for biogas production would have an edge in exporting such technologies in the future, at the same time boosting its energy independence.

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However, there are numerous and legitimate doubts raised by experts at scientific meetings, doubts that cannot be ignored. 

Here are the main ones:

Land use and exfoliation of farmland: a central power plant of biogas will need 300 acres of farmland. There will be less land left for agriculture and production of food resources. On the one hand, it is true that the amount of abandoned agricultural land is increasing. But on the other hand converting this abandoned land for energy production would drastically change the soil composition.

Fertilizers and pesticides (used in large quantities to grow the necessary amount of plants), will contaminate the surrounding atmosphere and groundwater.

Unpleasant odours: this may seem a relatively minor and easily circumvented point,ince building a plant outside of the populated area is totally possible. But in that case the plant will need more services and infrastructure. There would also have to be more trucks and transports moving to and from the plant to keep it in business. This way there will be more adverse effect on the environment.

Harmful bacteria: it was recently discovered that some bacteria used during the fermentation process are heat resistant, especially clostridium, which is a bacteria belonging to the same family as the bacteria that cause tetanus and botulism. The elimination of bacterial material within the anaerobic digesters (tanks in which the organic part degrades to transform them into methane) seems impossible till now. This also raises the issue of safe storage of waste derived from industrial cycle. This is a very serious problem because these bacteria can spread into the land and groundwater and thus causing disease.

Last risk to consider: certainly there is good intention behind the enthusiasm for biogas, but this enthusiasm is a bit rushed. It is certain that the laws will be firm and checks will be carried out. But there is a possibility that the industry will turn into a speculative business, criminals and other illegal activities may present a danger to a country that aims to develop this industry.

Some people think that these objections are pure prejudices, but experience often proves otherwise…

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