Monday, 21 June 2021
The Drax Group signed a deal with Mitsubishi on 10 June 2021, allowing them to deploy the latter's carbon capture technology on their biomass-fired power plant, paving the way for negative emissions in the future.
The carbon capture technology, based on Mitsubishi proprietary solvents can capture flue gas carbon emissions from Drax power station. When applied to fossil fuel emissions, carbon emissions are appreciably reduced.
Negative emissions become possible when renewable biomass fuel is used, as carbon emissions arising during operation are already compensated by carbon absorption during biomass growth, thus any carbon captured and removed from the atmosphere results in below zero emissions. This specific technology solution is known as Biomass Energy and Carbon Capture and Storage, or BECCS. The Drax group could potentially use these negative emissions to compensate for net emissions elsewhere.
Will Gardiner, Drax Group CEO, said: “Carbon capture technologies like BECCS are going to be absolutely vital in the fight against the climate crisis.”
However, he also suggested carbon removal activity may be profitable in itself: "Over time, that will not only be a climate imperative, but a very big business opportunity".
The BECCS unit at Drax could be operational as soon as 2027, and by 2030 is expected to capture and store at least 8 million tonnes of CO2 per year.
Mitsubishi's capture technology relies upon amine chemical solvents, which have an affinity for carbon dioxide. The capture process is similar to those used in the oil and gas industry to 'sweeten' gas streams:
Where RNH2 is the amine chemical solvent. Thus the carbon dioxide (CO2) which comes out of the power plant flue gas is captured and converted to ammonium cation and bicarbonate, shown on the right hand side of the above equation. The process is reversible, meaning the carbon can be released and stored downstream, and the amine solvent can be recovered, free to capture further carbon.
For the Drax, the intention is to transfer the captured carbon to a repository under the North Sea.
The BECCS technology is not without cost of course, requiring capital investment for plant additions. There are also costs associated with maintenance and operation, although these activities can also present job opportunities.
Another important consideration is the energy required for processing and capture, which will reduce the overall MWh electricity output per tonne of biomass used at the power station. At this stage, both parties remain tight-lipped about the energy cost of the BECCS process.
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