Biogas is a model example of the circular economy

The circular economy offers a path for sustainable growth as consumption and production requirements grow. The biogas production process is a good example of this.

The circular economy will play a significant role in meeting the global climate targets. The European Commission put forward its first Circular Economy Package in 2015. The Waste Framework Directive states that 65% of municipal waste must be prepared for re-use and recycling by 2035.

The circular economy is about more sustainable utilization of natural resources, recyclability and waste reduction. Its basic principle is to do more with less.

Waste from one pro­duct is the building material for another product

Biogas production is a good example. Biogas is a low-emission fuel produced from agricultural, industrial and household waste. Biodegradable material can be recovered for energy production, which reduces energy loss and eliminates the fine particulate emissions that would have resulted from waste incineration.

Nutrient residues created as a by-product can be returned to the food chain as fertilizers or refined for industrial purposes to replace mineral and fossil nutrients and fertilizers. Renewable biogas can be used as a fuel for cars, buses, heavy-duty vehicles and maritime transport.

Biogas use can help to reduce greenhouse gas emissions by up to 90% compared with fossil fuels.

Stages in biogas production

1. Biowaste is crushed into smaller pieces and slurrified to prepare it for the anaerobic digestion process. Slurrifying means adding liquid to the biowaste to make it easier to process.

2. Microbes need warm conditions, so the biowaste is heated to around ­37 °C.

3. The actual biogas production takes place through anaerobic digestion in large tanks for about three weeks.

4. In the final stage, the gas is purified (upgraded) by removing impurities and carbon dioxide.

5. After this, the biogas is ready for use by enterprises and consumers, for example in a liquefied form (LBG) or following injection into the gas pipeline network.

The biogas produced can be used for purposes such as fuelling municipal waste management vehicles, urban buses, private cars or heavy-duty vehicles. At the same time, gas serves as evidence of those practical actions that are taking us towards the low-carbon society of the future.

Updated 28.9.2021