The by-product of this burn is a mixture of nitrogen, CO2 and water collectively termed flue gas.Ī wide variety of filtration systems can pluck the CO2 from this mixture. The heat produced inside this boiler is used to convert water to steam that in turn powers a set of turbines to produce energy. It has the advantage of being able to be retrofitted to existing power plants.įuel is injected into a boiler with air and burnt in the same way you would typically find at a coal, oil, or gas-fired power plant. Post-combustion is another technique used to capture CO2.

To maximise the efficiency of the process, the heat produced by burning the hydrogen is redirected to convert water to steam and so produce more electricity using conventional steam turbines. Separating these two gases produces a stream of hydrogen, which is burnt off, and CO2, which is dehydrated to remove any leftover water and compressed to concentrate the gas into a liquid form for transport and storage. Collectively this is known as syngas.īy adding water to this syngas in a shift reactor, it is converted into hydrogen and CO2.

This is then fed into a unit known as the gasifier, which bakes the coal at around 700☌, releasing a mixture of gases including hydrogen, carbon monoxide, CO2 and steam. Pre-combustionĪs the name says, a pre-combustion setup focuses on capturing CO2 before the fuel is burnt.įirst, an air separator strips oxygen from the atmosphere, producing an almost pure stream of oxygen gas.

Three main approaches have been developed to do this: pre-combustion, post-combustion and oxyfuel combustion. When fossil fuels are burnt they produce a range of different gases including oxygen, nitrogen and CO2.ĬCS focuses on selectively pulling this CO2 out of the gas mixture and preparing it for underground storage.

One approach to keeping carbon emissions under control is the use of carbon capture and storage (CCS) technologies that use underground rocks as “storage tanks”. When a coal, oil or gas plant burns fuel to create electricity, a major by-product is the greenhouse gas carbon dioxide (CO2).

Carbon capture and storage