Earlier this month, I wrote about new reports produced by the Electric Power Research Institute on behalf of the Global CCS Institute. I have already covered an update on post-combustion and pre-combustion capture technologies within the power sector. Today I will focus on the other capture option: oxyfuel.

In oxyfuel-combustion processes, the bulk nitrogen is removed from the air before combustion. The resulting combustion products will have CO₂ content up to about 90 per cent (dry basis). The flue gas impurities (predominantly O₂, N₂, and Ar) may be removed by reducing the flue gas (at moderate pressure) to a temperature at which the CO₂ condenses and the impurities do not. Oxyfuel-combustion may be employed with solid fuels such as coal, petroleum coke, and biomass, as well as liquid and gaseous fuels.

Some key points raised in the oxyfuel-combustion carbon capture report are:

• The oxyfuel-combustion/CO₂ capture power plant designs being developed and deployed for service in the next four or five years are based on individual component technologies and arrangements which have demonstrated sufficient maturity, with the greatest remaining technical challenge being integrating the systems into a complete steam-electric power plant.
• By its nature, an oxyfuel-coal power plant is likely to be a 'near zero' emitter of all criteria pollutants.
• Existing air-fired power plants might be retrofitted with an air separation unit, oxyfuel-fired burners, flue gas recycle, and a CO₂ processing unit, with the large fleet of air-fired power plants in service calling for more study of this option.
• Future efficiency improvements to the oxyfuel-combustion process for power generation point toward an oxyfuel-combustion plant with near zero emissions of conventional pollutants, up to 98 per cent CO₂ capture, and efficiency comparable to the best power plants currently being built.

The knowledge products should appeal not only to technical stakeholders, but also to non-technical project people as well as other stakeholders responsible for regulatory and funding of large-scale integrated projects, particularly in the power industry. The full report is available on the Institute site.