Low CO2 emission fossil-fueled fired power plants

Following COP21 in Paris and then COP24, countries around the world agreed to limit the rise in the planet's average temperature to 1.5°C by 2050 by cancelling greenhouse gas emissions, particularly CO ₂ emissions. That leaves a good ten years to reach such a target, if it's still realistic under current political conditions with coal use either maintained by extending the operation of existing power plants (USA, China, India, Poland....), or stepped up by replacing nuclear power plants (Germany). In any case, the strategy of a massive and rapid reduction in CO ₂ emissions implies the implementation of CO ₂ capture and storage in power plants, mainly coal-fired but also natural gas-fired, according to one of the COP24 recommendations.

The three technologies examined in this article are post-combustion carbon capture (in the flue gas), pre-combustion carbon capture (fuel decarbonization) and oxy-combustion. The latter applies to pure-oxygen combustion in boilers and combined-cycle gas turbines, and is highly attractive as the closest thing to "zero emissions".

Currently, the most mature carbon capture technique used in industry is amine absorption of the CO ₂ present in post-combustion fumes. It is the most suitable for the scale of power plants of several hundred MW.

To separate CO ₂ , derived from the use of fossil fuels (in this case coal and natural gas), from one or more other components in a gas mixture, energy (thermal or electrical) must be used, which depends on the molar mass of the components and their concentration. This separation energy will therefore reduce the net energy produced by the power plant and for a fixed power output, reduce efficiency and increase fuel consumption, and therefore paradoxically increase the amount of CO ₂ generated