IGCC efficiencies are increased by using waste heat. Are IPFC efficiencies also calculated using waste heat?
No. Using “waste heat” from the Direct Carbon Fuel Cell and an optional solid oxide fuel cell employed in one of the IPFC plant designs would add to the stated IPFC efficiencies. The IPFC includes options for a “back-end” steam Rankine cycle using this “waste heat” to maximize efficiency. However, it should be recognized that the energy or heat from the plasma cracking process is never wasted; rather it is recycled to the plasma and the feed processing system. Since it is not considered “waste heat,” it is not used in a Rankine cycle. Three flow diagrams, including one using a back-end Rankine cycle, are available in the 7-page pdf document summarizing the IPFC.
