Today, the carbon dioxide emitted from the flue-gas stacks of coal-burning power plants is measured to control the emissions of the pollutants sulfur dioxide, nitrogen oxides (nitric oxide, nitrogen dioxide), and mercury. However, present-day carbon dioxide emission measurements may have uncertainties in the range 5% to 10%. NIST is conducting research to reduce the uncertainties to 1% or 2%. These lower uncertainties will be needed if the US Environmental Protection Agency (EPA) puts a price on carbon dioxide emissions, for example by a carbon tax or by cap-and-trade regulations.Crowley, et al. discovered that the calibration can show hysteresis that gradually disappears as the turbulence in the flow increases. Thus calibrations must account for the turbulence in the flow to achieve the target accuracies of 1% or 2%. scale-model smoke stack test-bed to study calibration protocols. NIST is also studying unconventional techniques for measuring carbon dioxide emissions such as a long-wavelength acoustic flow-meter.
Created January 30, 2014, Updated September 21, 2016