Pre-Combustion Capture

With pre-combustion capture, carbon and hydrogen in a fossil fuel are separated prior to combustion. The fuel source becomes chemically transformed into two gas streams consisting of hydrogen and CO₂. The process diagram below outlines how pre-combustion capture works.

The Process:

• Air is purified in an air separation unit and pure oxygen (O₂ ) is extracted.
• The oxygen (O₂) is then sent to the gasifier where it reacts with the fuel source to create a synthesis gas, or syngas.  This syngas is a mixture of hydrogen (H₂) and carbon monoxide (CO).
• Steam is then added to the syngas in a shift reactor.  This converts the carbon monoxide (CO) to hydrogen (H₂) and carbon dioxide (CO₂).
• The entire process results in two pure gas streams of hydrogen (H₂) and carbon dioxide (CO₂) which can then be used as follows:
  • The hydrogen can be burned cleanly to create steam which, in turn, will run a turbine to make electricity or be used for other industrial applications.
  • The pure carbon dioxide (CO₂) can be captured, compressed for transportation and stored.