The Environmental Impact of Biogas
Biogas production is rapidly increasing across Europe, and it is widely seen as a more sustainable alternative to fossil fuels. The gas is created from methane via anaerobic digestion – the process of organic matter breaking down in either landfills or digesters that are specifically made to convert animal and food waste into gas. With more and more plants being set up to create this greener fuel, many are pausing to ask the question, is biogas really that green and are there currently any issues with it?
Positive environmental impacts of biogas
Currently, there are several positive environmental impacts that come with the production of biogas, including:
More sustainable alternative to fracking
One of the benefits of biogas is that it is a much more sustainable solution than fracking for gas. Fracking is a process which involves forcing water, chemicals and sand deep into the ground to break up formations of rock. This method is incredibly harmful to the environment with considerable damage being done to ecosystems and landscapes. Interestingly, creating biogas from landfills and digesters creates a very similar fuel to natural gas, but with much less harm to the environment.
A renewable energy source
All the materials that go into biogas production such as trees, crops, food and animal waste are completely renewable, making it a highly sustainable option. As an added benefit, biogas production uses materials that would otherwise go to waste, so it could potentially reduce wastage too.
Reduces methane emissions
Biogas production significantly reduces harmful methane emissions which is one of the largest greenhouse gases responsible for climate change. When organic waste decomposes in landfill, it causes the gas to be released. By capturing the methane to be used as a fuel instead of allowing it to dissipate into the atmosphere, biogas production plays a part in drastically reducing the climate impact. Furthermore, the gas generated from bio-digestion is non-polluting since no combustion takes place, meaning no greenhouse gas emissions will be released into the atmosphere.
Biogas has numerous uses
Biogas can be further processed in a biogas upgrading facility to become biomethane and serve as a suitable replacement for natural gas by removing carbon dioxide, hydrogen sulfide, water and contaminants. When refined in this way, biogas can be used for electricity production and heating for industrial and residential buildings and can even be used as fuel for engines.
Reduces soil and water pollution
Creating biogas could potentially lead to less soil and water pollution surrounding landfill sites. When landfills overflow, contaminated liquid can drain out and leach into underground water sources. This contamination, or leachate, is very toxic to natural life. By collecting this waste and putting it into anaerobic digesters instead, we reduce the amount of organic waste in landfills which may, in turn, improve the water quality. Additionally, the process of anaerobic digestion deactivates pathogens and parasites, potentially reducing the risk of waterborne diseases.
Zero waste
Nothing is wasted when it comes to biogas production. Where the bulk of the organic waste becomes biogas, the leftovers or ‘digestate’ goes on to be made into nutrient-rich, organic fertilizer. This fertilizer is completely natural and may reduce the need for chemical options in the future. Using this natural fertilizer may improve plant growth and make crops much more resilient to certain diseases, resulting in better crops and less harm to the planet.
Environmental issues with biogas
While biogas is a much more sustainable solution to natural gases, that does not mean it is completely free from problems. Some of the largest concerns with biogas production currently are as follows:
Use of energy crops may be harmful to the environment
It has become popular for biogas plants to use ‘energy crops’ such as maize to produce a much higher energy yield from the decaying organic waste. However, cultivating plants such as these can cause soil erosion and these plants also produce much higher carbon emissions than other types of organic waste.
Not enough biogas for a complete gas replacement
Where biogas can certainly reduce our reliance on fossil fuels such as oil and coal, there is not enough biomass to generate the amount we need to completely replace our gas supply. At present, biogas has the potential to replace just 20% of the world’s gas demand, so more focus needs to be put into harnessing wind and solar powers in order to reach net zero.
It leads to delayed action
In many areas, biogas is being used to delay the transition to zero-emission energy systems. Those that rely heavily on gas are mixing only a small portion of biogas into their networks and are avoiding and delaying the complete elimination of fossil fuels.
It could lead to more waste
One of the potential concerns with biogas production is that it may lead to more waste. As it relies on the decomposition of organic waste, biogas production may encourage those involved to waste purely for the purpose of creating biogas.
Biogas certainly has a part to play in reducing global warming and the world’s reliance on fossil fuels, but it is not a complete and perfect solution. However, when used in tandem with other renewable energy sources such as wind and solar, biogas production can be a very worthwhile energy source and help with reaching net-zero targets.
For more information on biogas and biomethane, read our guide on how long it takes to produce biogas, next.
