Pilot Test Results from a PolarisTM Membrane 1 MWe CO2 Capture System

To mitigate the harmful effects of global climate change, CO₂ in combustion sources must be captured and either sequestered or utilized. Membrane technology is an attractive CO₂ capture option because of advantages such as energy-efficient passive operation, small footprint, no hazardous chemical emissions, handling or storage issues, and reduced water requirements.

Working with the U.S. Department of Energy, MTR has developed new membranes and process designs to recover CO₂ from combustion gases. Polaris^TM membranes offer the highest combination of CO₂ permeance and CO₂/N₂ selectivity of any commercial membrane today. These membranes are combined with a novel process design that uses incoming combustion air to sweep membranes and recycle CO₂ to the combustion process. Design calculations estimate that this membrane process can capture CO₂ at a cost $40-$50/tonne, which is competitive with leading second generation capture approaches.

Over the past 5 years, MTR has operated a system at the National Carbon Capture Center (NCCC) testing commercial-scale Polaris modules capturing 1 tonne CO₂/day. Overall, this system has accumulated run time of over 11,000 hours, and demonstrated stable membrane performance. With this experience, MTR designed and built a scaled-up pilot unit to capture 20 tonnes CO₂/day from a slipstream at NCCC (equivalent to 1 MW_e-scale coal-fired power generation). This system was operated for about 1500 hours in 2015. During testing, advanced Polaris modules demonstrating higher packing density, lower pressure drop, and higher permeance were validated. After completion of testing at NCCC, the 20 tonne CO₂/day unit was moved to Babcock & Wilcox’s (B&W) boiler research facilities for a fully integrated recycle test of the membrane unit with a coal-fired boiler. This test demonstrated boiler operation with CO₂-laden air recycled by a membrane for the first time. Technical results from these field tests and future plans will be discussed in this presentation.