| OCR Text |
Show 4 straighteners around the primary stream. Injection of fuel particles into the hot gas stream results in their rapid heating to the prevailing gas temperature. Following a rapid heating period, pyrolysis, gasification and/or combustion of particles occur for a specific time (dictated by the transit distance). All reactions are then rapidly quenched in a water- and/or steam-cooled sampling probe. Solid products are separated from gaseous products in a small filter housing. Aliquots of the effluent gas stream are sent to a Fourier Transform Infrared (FTIR) spectrometer, Gas Chromatograph (GC) and/or a Gas Analysis System (GAS) for measurement of the concentrations of various major and minor gaseous constituents. A personal computer-based data acquisition system records, on demand, all relevant test datalinformation. This facility has been described elsewhere (Regan, et aI., 1994). For this particular application, specific aliquots were also sent to a Tedlar Bag (TB), a Modified Method-5 (MM-5) sampling train, or a Methylene Chloride (MeCI2) bath, as shown in Figure 1, for measurement of the various organic air toxies compounds. Test Matrix and Procedures. A 400x0-mesh size fradion of a bituminous coal sample was used in this study. Two different combustion tests were evaluated: (1) a relatively high NOx condition (simulating no combustion staging), with an oxygenJfuel stOichiometry of apprOximately 1.9; and (2) a relatively low NOx condition (simulating combustion staging), with an oxygenJfuel stoichiometry of approximately 0.9. Additionally, one pyrolysis test was run to derive qualitative air toxies information from the coal's tar and volatile matter. The combustion tests were carried out in an oxygen/argon gas mixture at 2650 OF and about 1.5 sec. residence time. The pyrolysis test was performed in pure argon gas at 2650 OF and about 0.15 sec. residence time. The gas mediums used effectively eliminated the formation of thermal NOx' The measurement techniques/protocols used and target compounds measured are identified in Table 1. Essentially, EPA-sanctioned protocols and in-house methods were used in the evaluation. The FTIR and GC were used to measure such compound |
