Microwave Doppler for sensing of particulate flows

Chemical looping combustion systems [B. Kronberger, C. Beal, J.-X. Morin, H. Hofbauer, "Design, hydrodynamic testing and scale-up recommendations of a conceptual large-scale chemical-looping combustion power plant," DOE NETL Conference, Washington DC, USA, (May 2004)] have an exhaust consisting almost entirely of carbon dioxide and water vapor. After condensation of the water vapor the carbon dioxide can be utilized or stored without the need for an expensive separation process, making chemical looping combustion potentially more cost and energy efficient than a conventional boiler with carbon dioxide separation added to the exhaust cleanup.  Thsi research is directed at the application of microwave Doppler sensing to chemical looping combustion systems. 


The figure above shows an experimental chemical looping reactor system presently at NETL.  Oxygen carrier particles (typically a metal oxide) are oxidized in the air reactor and are transported to the fuel reactor.  In the fuel reactor, the particles are reduced in reactions with the fuel, and then returned to the air reactor.  The circulation rate [mass/ unit time] is a key process parameter. Measurement of the circulation rate is challenging because the system is pressurized and is operated at high temperature (~ 1000 °C). We are developing a microwave Doppler sensor to measure the particle velocity and the particle density independently. The sensor is to be located at the upper crossover in the figure.

Challenges in this project include:

Below are selected publications. Some citations are linked to a draft of the paper; for the final version consult the journal or conference proceedings.

Conference papers