The US Department of Energy has selected two projects to demonstrate oxycombustion, a promising carbon capture technology, in existing coal-fired power plants. The projects, valued at nearly $10 million, are expected to help expedite the timeline for commercialisation of oxycombustion technology through slipstream or pilot plant testing.
In an oxycombustion-based power plant, oxygen rather than air is used to combust a fuel resulting in a highly pure carbon dioxide (CO2) exhaust that can be captured at relatively low-cost and sequestered.
According to the DoE, no commercial oxygen combustion power plants are operating today, due mainly to the high cost of producing oxygen. Significant reduction in the cost of oxygen compared to today’s best cryogenic technology is a key requirement to making the oxycombustion power plant a viable future option. The two projects selected by DOE show promise for reducing those costs when compared to existing CO2 capture systems.
B&W and its team will conduct five-million Btu per hour pilot-scale tests across a range of coal types including: Eastern bituminous coal, Power River Basin pulverised coal, sub-bituminous coal, and lignite coal.
The team will optimise the oxycombustion process by performing parametric testing in wall-fired and cyclone boiler configurations. B&W’s project expects to demonstrate that those cyclone boilers retrofitted with oxycombustion technology will demonstrate a cost-effective approach for CO2 capture coupled with much lower nitrogen oxide emissions. The total value of this project is $3.5 million and it will be carried out over a two-year period.
The BOC Group plans to capture CO2 by combining oxycombustion technology with flue gas recycle in a process that replaces combustion air with a mixture of oxygen and recycled flue gas to produce a carbon dioxide-rich flue gas for sequestration.
To reduce the cost of oxygen production, BOC plans to apply its CAR (Ceramic Autothermal Recovery) oxygen production process that uses the mineral Perovskite to absorb oxygen and subsequently release it in a circulating fluidised bed and pulverised coal pilot-scale firing configuration. The total value of this three-year project is $6.1 million.