Air Products is a recognized leader in the emerging field of Oxyfuel CO2 capture technology. Our Oxyfuel combustion system coupled with our unique compression/purification technology can represent a carbon capture and sequestration (CCS) system with the potential to produce electricity economically from coal while creating a CO2 stream of the purity required for either sequestration or EOR.
Not only is our Oxyfuel technology applicable to new-build supercritical power plants, but it also can provide a solution for retrofitting the existing installed base of coal-fired and oil-fired power plants.
Oxyfuel combustion enables lower capture cost by increasing the concentration of CO2 in flue gas. However, the other conventional products of combustion remain present in the flue gas: water vapor; oxygen; nitrogen (albeit reduced); argon; acid gases such as SO3, SO2, HCl, and NOx. To prevent corrosion and comply with likely specifications for sequestration, the acidic impurities will need to be removed from the CO2 stream before it is introduced into the pipeline. There may also be other stringent requirements on purity, particularly for applications such as Enhanced Oil Recovery (EOR).
In order to treat the acidic components and remove inerts from the oxyfuel flue gas, Air Products is developing a novel specialized combined CO2 compression and purification process. This proprietary process creates conditions in which essentially all of the SOx and about 90% of the NOx may be removed from the flue gas and offers the potential for CO2 purities in the range 95-98%.
The gas can then be dried and compressed for transportation for sequestration or EOR. Modifications to this cycle could allow purities of CO2 greater than 99.9 mol % with only ppm levels of oxygen, a key purity criterion for EOR.