What is Anaerobic Digestion?

Anaerobic digestion is an increasingly popular process in the UK for generating renewable energy from organic waste. It is a natural process whereby food waste and other organic materials are broken down in a sealed vessel, known as a digester, to produce a biogas that can be used to generate electricity, heat, and biomethane for injection into the gas grid.


How Does Anaerobic Digestion Work?

The anaerobic digestion process takes place in an airtight container called an anaerobic digester. Inside the digester, bacteria break down organic matter in the absence of oxygen, producing biogas as a by-product. The biogas can then be used to generate energy.

Before being fed into the digester, the organic waste is typically pre-treated to ensure efficient digestion. This can involve shredding, mixing, and separating the waste to remove contaminants such as plastics and metals.

Once inside the digester, the waste is heated and agitated to promote the growth of bacteria. The bacteria break down the organic matter, producing biogas as a by-product. The biogas can then be used to generate electricity and heat, either by burning it directly or by running it through a generator to produce electricity.


Anaerobic Digestion Working
Typical Anaerobic Digestion Container


Why is Anaerobic Digestion Becoming More Popular in the UK?

Anaerobic digestion is becoming a popular technology in the UK for several reasons.

  1. Landfill Alternative : It can help to reduce the amount of organic waste that is sent to landfill. This not only reduces the amount of methane, a potent greenhouse gas released by organic waste, but also helps to generate more renewable energy.
  2. Energy Production: Anaerobic digestion plays an important role in addressing the current energy crisis in the UK. The country is currently facing a shortage of natural gas, which is used to generate electricity and heat. Biomethane produced through anaerobic digestion can help to supplement the natural gas supply and reduce dependence on fossil fuels.
  3. Emissions Reduction: The use of biomethane produced through anaerobic digestion can help to decarbonise the energy grid and reduce greenhouse gas emissions in the transportation sector.

Anaerobic digestion is an incredibly promising technology that can help to tackle both waste management and energy production, while also supporting the UK’s transition to a low-carbon economy.


What are the Downsides to Anaerobic Digestion?

While anaerobic digestion offers many benefits, there are also some downsides to consider:

  1. High Start-Up Cost: The cost of setting up an anaerobic digester can be high, which may deter some businesses or individuals from investing in the technology.
  2. Odour Pollution: Anaerobic digestion facilities can produce unpleasant odours, which can be a problem for people who live nearby. However, this can be mitigated through the use of appropriate technology and siting of facilities.
  3. Potential Contaminants: There is a risk that the liquid waste produced during the process could contaminate groundwater if it’s not handled properly. This can be mitigated through the use of appropriate storage and handling facilities.
  4. Takes Away from Animal Feed: Whilst anaerobic digestion is a better alternative than landfill, animal feed is still a more sustainable option for organic food products that remain fit for consumption. There could be an overreliance on anaerobic digestion for organic products that could more sustainably be used elsewhere, as it could be seen as a one size fits all solution, when it should only be a small part of bringing about a circular economy. 


A Better Alternative to Landfill

Overall, anaerobic digestion is a promising technology that can help to tackle both waste management and energy production. By diverting food waste and other organic wastes from landfill, we can reduce greenhouse gas emissions and generate renewable energy. With appropriate investment and management, it has the potential to help address the challenges of both waste management and climate change. By embracing this innovative approach, we can make significant strides in reducing greenhouse gas emissions, conserving valuable resources, and promoting a greener future.

Are you looking for alternate ways to divert organic products away from landfill? Contact Mobius, the leading waste management experts, to get a free quote using the form below: