What is bioenergy with carbon capture and storage (BECCS)?
Exploring how sustainable biomass can deliver negative emissions. The 3rd in our series ‘Powering to net zero’.
Bioenergy with carbon capture and storage (BECCS) is the name given to the process of capturing and permanently storing the carbon dioxide (CO2) produced when generating electricity from biomass.
Why does BECCS matter so much for decarbonisation?
When combined with carbon capture and storage, sustainable bioenergy can achieve more than carbon neutrality. In fact, it can be a source of negative carbon dioxide emissions, as carbon capture and storage permanently removes CO2 from the carbon cycle.
Experts including the Committee on Climate Change agree that negative emissions technologies (NETs) are essential in helping us meet our commitments to the Paris Climate Agreement.
BECCS is the NET that can be most easily introduced at the required scale in the coming decade. So it will have a huge role to play.
Where does the bioenergy in BECCS come from?
The majority of bioenergy is generated by boilers or furnaces using biomass fuel to produce high-pressure steam to power electricity-generating turbines.
How is the carbon captured?
BECCS employs what is known as a post-combustion carbon capture process. In this process, special solvents are used to isolate CO2 from the other flue gases produced when the biomass fuel is combusted. The CO2 captured in this way is then pressurised and transported by pipeline to be stored — without ever being released into the atmosphere.
How is the captured carbon stored?
Once captured, CO2 can be injected into porous rock formations which occur naturally. These could include unused natural gas reservoirs, unworkable coal beds, or water permeable rocks that are saturated with salt water known as saline aquifers. This safe and permanent process is called sequestration.
As time passes, the captured and sequestered CO2 may undergo a chemical reaction with the minerals around it, holding it in mineral storage.
The facts about BECCS
- Just two 600+ megawatt (MW) biomass units, upgraded with carbon capture technology, are all that would be needed to deliver 40% of the negative emissions the Climate Change Committee states will be required from BECCS in order for the UK to reach net-zero by 2050
- BECCS could help remove 20–70 million tonnes of CO2 per year in the UK by 2050
- The UK offers 70 billion tonnes of potential CO2 storage space around the UK, according to the British Geological Survey