One of the important goals of this project is the control of SO₂ emissions to the atmosphere from coal-fired power plants. Any economical reduction of the sulfur content of coal used by utilities is gained through the blending of various coals or through coal washing. Accurate blending is impossible if the composition of the coals to be blended and/or the blended coal are not known on a real-time basis. This analyzer measures on-line, on a minute by minute basis, the sulfur content of coal along with other important coal bulk parameters such as heat content (Btu), moisture, density, volatile matter etc., that affect the efficiency of the power plant. The main features of the analyzer, which is based on pulsed fast/thermal neutrons, are self-calibration independent of the coal seam, better accuracy in the determination of elements such as carbon, oxygen and sodium, and reduced radiation hazard during maintenance. This on-line coal analyzer is to be used by coal mines, coal preparation plants and coal-fired power plants worldwide.

This on-line analysis method uses microsecond-wide 14 MeV neutron pulses produced from a sealed tube neutron generator. The fast 14 MeV neutrons slow down upon interaction with the light elements in coal (primarily hydrogen) resulting in the presence of low energy or thermal neutrons. The 14 MeV neutrons also initiate longer-lived (seconds or longer) activation reactions. The analyzer contains a coal handling system, and several gamma-ray detectors for the measurement of elemental concentrations (see Pulsed Fast Thermal Neutron Analysis) These elemental concentrations are derived from the detected gamma rays resulting from the various neutron reactions (fast, thermal, and neutron activation). A laboratory prototype analyzer installed in a 40 ft trailer was operated for three years. The data (see Publications) indicate that C and O can be measured with precision so that the coal calorific value can be established, irrespective of the rank of the coal flowing through the analyzer. A redundant set of self-corrections of the gamma-ray intensities compensates for elemental composition changes due to coal seam changes. Sodium has been measured in real time with a minimum detection limit close to 200 ppm.

The first commercial prototype of this analyzer was built by the Applied Physics Institute for NUMAT, Inc. This commerical prototype is currently being installed at the Cumberland Fossil Plant in Cumberland City, TN by API personnel in conjunction with the Tennessee Valley Authority and Electric Power Research Institute (EPRI). This analyzer represents >$1M project by the TVA to help prove this technology.

The images above show, from left to right, the prototype coal analyzer at Western Kentucky University and the commercial prototype analyzer as installed at the Cumberland Fossil Plant in Cumberland City, TN.

For more detailed information, please access the Publications portion of this web site.