AN INTRINSICALLY SAFE, LASER-BASED OPTICAL DIAGNOSTIC FOR HOT GAS STREAM CLEANUP

THIS RESEARCH FACILITATES THE DEVELOPMENT OF DIODE LASER-BASED INSTRUMENTS THAT PROVIDE EXCEPTIONAL SENSITIVITY AND SELECTIVITY FOR THE REAL-TIME DETECTION OF IMPORTANT GASES IN HARSH, HIGH TEMPERATURE, HIGH PRESSURE ENVIRONMENTS. THESE INSTRUMENTS TARGET THE NEEDS OF COAL-FUELED ENERGY CONVERSION SYSTEMS THAT REQUIRE HOT GAS CLEANUP PROCESSES TO REDUCE EMISSIONS. THIS APPROACH, WHICH MEASURES ABSORPTION IN THE NEAR-INFRARED SPECTRAL REGION, USES RELIABLE, RELATIVELY INEXPENSIVE SOLID STATE LASERS COMPATIBLE WITH FIBER OPTICS. THE LASERS CAN BE INCORPORATED INTO FULLY AUTOMATED, INTRINSICALLY SAFE, SELF-CALIBRATING INSTRUMENTS CAPABLE OF CONTINUOUS ON-LINE OPERATION. THE TECHNIQUE SHOULD BE USEFUL FOR DETECTING AMMONIA, HYDROGEN SULFIDE, HYDROGEN FLUORIDE, HYDROGEN CHLORIDE, NITROGEN DIOXIDE, NITROGEN TRIOXIDE, CARBON MONOXIDE, AND CARBON DIOXIDE. IT IS LIKELY THAT THE TECHNIQUE CAN BE EXTENDED TO OTHER GASES INCLUDING BENZENE, FORMALDEHYDE, ETHYLENE, AND ACETYLENE. THE PLANNED RESEARCH IS DIRECTED TOWARDS COAL-FUELED SYSTEMS INCLUDING PRESSURIZED, FLUIDIZED BED COMBUSTION; DIRECT COAL-FUELED TURBINES; INTEGRATED GASIFICATION COMBINED CYCLE, GASIFICATION/MOLTEN CARBONATE FUEL CELLS; GASIFICATION/SOLID OXIDE FUEL CELLS; COAL-FUELED DIESEL; AND MILD GASIFICATION. IN PHASE I, LABORATORY EXPERIMENTS ARE BEING CONDUCTED TO DEMONSTRATE THE TECHNIQUE FOR AMMONIA DETECTION AT TEMPERATURES UP TO 1,200 K. THE PHASE I EXPERIMENTS ARE MEASURING ALL SPECTROSCOPIC PARAMETERS REQUIRED TO ESTABLISH THE SENSITIVITY AND SELECTIVITY OF THE TECHNIQUE FOR IN-SITU MEASUREMENT OF AMMONIA IN HIGH TEMPERATURE, HIGH PRESSURE ENVIRONMENTS.