Precombustion Decarbonisation Technologies

In pre-combustion capture technology concept, CO₂ is separated from a high H₂ content gas mixture, product of coal gasification or natural gas steam reforming in high pressure. The most common practice is the physical absorption of CO₂ with Rectisol or Selexol solvents. Pre-combustion decarbonisation technologies implemented in IGCC power cycles and / or natural gas-based IRCC, offer the following advantages:

• Avoidance of CO₂ dilution by the combustion air
• Owing to the system pressure (30-60 bar) more efficient separation methods can be applied e.g. using pressure swing adsorption
• Possibility to transfer experience from the chemical and refinery sectors where similar concepts are used

Simplified Process flowsheet diagram of pre-combustion concept

However, within the field of precombustion decarbonisation further research efforts should be directed towards:

• Validation of absorption technologies in integrated pilot plants
• Novel reactor concepts for separation of CO₂ and H₂ rich fuel gas (membrane adsorption and absorption for the enhanced reforming/gasification process)
• Development of new gas turbines, especially combustors for hydrogen -enriched fuel gas. This topic is thoroughly investigated within ENCAP SP2 and experiments on existing burner design have successfully completed showing that basic burner concepts are suitable platforms for further burner development work for H₂-rich fuels
• Integration of new process steps components design in order to optimize the plant’s operating conditions. Within the ENCAP project and for the time being different intermediate gas processing steps has been selected and the way of their integration into power plant concepts has been determined