NRG Energy and Powerspan Corp could become the first companies in the world to demonstrate carbon capture and storage (CCS) on a commercial scale with the development of a project that will capture and sequester about 1 million tons of CO2 per year.
The two companies have signed a memorandum of understanding to demonstrate Powerspan’s ECO2 technology on a commercial scale at NRG’s coal fired WA Parish power plant in Texas. The project will capture CO2 from flue gas equal in quantity to that from a 125 MW unit, ranking it among the world’s largest CCS projects.
To date, CO2 capture demonstrations on coal-fired plants have only been conducted at pilot scale, or 1-5 MW, says Powerspan. The CO2 from this project will be used in enhanced oilfield recovery operations in the Houston area.
ECO2 is a scrubbing process that uses an ammonia-based solution to capture CO2 from flue gas and release it in a form ready for transportation. The new demonstration facility will be designed to capture 90 per cent of incoming CO2 and is expected to be operational in 2012.
According to Powerspan, the ECO2 process has a simpler design and lower energy consumption compared to other carbon capture technologies. It can be retrofitted to existing coal fired plant and integrated with the company’s Electro-Catalytic Oxidation (ECO) multi-pollutant control system.
Powerspan has been collaborating with the US Department of Energy National Energy Technology Laboratory on development of the CO2 removal process since May 2004.
The project is part of NRG’s wider repowering programme, which aims to add 10 000 MW of power to the US grid using diverse fuel sources and technologies including nuclear, wind and IGCC.
“As part of our aggressive effort to ‘get the carbon out of coal’ we are proud to help demonstrate the viability of this promising technology for power-combustion carbon capture at WA Parish,” said David Crane, President and CEO of NRG Energy. “The successful deployment of clean coal technology like ECO2 is absolutely essential to our common goals of reliable and affordable electricity, enhanced energy security and reduced greenhouse gas emissions.”
In the ECO2 process, CO2 capture takes place after the NOx, SO2, mercury and fine particulate matter are captured. Once the CO2 is captured, the ammonia-based solution is regenerated to release CO2 and ammonia. The latter is then recovered and sent back to the scrubbing process, and the CO2 is ready for geologic storage.