(165g) Cost of Electricity of a Staged, Pressurized Oxy-Combustion Power Plant

The immediate need for low cost carbon capture processes has prompted the recent development of pressurized oxy-combustion processes [1-3]. At increased combustion pressure, dew point of flue gas moisture is increased, allowing for effective integration of the latent heat of flue gas moisture condensation into the Rankine cycle. This increases the net plant efficiency and reduces costs. The Staged, Pressurized Oxy-Combustion (SPOC) process further enhances the efficiency and reduces costs by reducing the recycle of flue gas to near zero. This is achieved by staging the delivery of fuel and, thereby, using excess oxygen along with the combustion products of previous stages as diluents to manage the temperature and heat flux during the combustion process. Compared to first generation oxy-combustion, SPOC process results in an increase in net plant efficiency of about 5 percentage points.

The cost of a 550 MW_e SPOC power plant, modeled in ASPEN Plus, with 90% carbon capture is described. The effect of other factors such as contingencies, cost of CO₂ and financial structure, etc. on the cost of electricity is analyzed. Results show that in comparison to an air-fired combustion power plant without carbon capture, the SPOC process can limit the increase in cost of electricity to less than 35%, in line with the US Department of Energy’s goal.

Acknowledgements

• This material is based upon work supported by the Department of Energy under Award Number DE-FE0009702.
• Ameren advising team: Rich Smith, Tom Callahan, George Mues.
• Engineering, consulting, and cost estimation services provided by Burns & McDonnell.

Disclaimer:

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of the authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

References: 

1. Gopan, A., et al., Process design and performance analysis of a Staged, Pressurized Oxy-Combustion (SPOC) power plant for carbon capture. Applied Energy, 2014. 125(0): p. 179-188.
2. Hong, J., Techno-economic analysis of oressurized oxy-fuel combustion power cycle for CO2 capture. 2009, MIT: Cambridge.
3. Zheng, L., et al. Optimization of a high pressure oxy-fuel combustion process for power generation and CO2 capture in International Technical Conference on Coal Utilization & Fuel Systems. 2010. Clearwater, Florida, USA.