High-Pressure Coal Combustion: Characterization of the Near-Burner Flame Zone

摘要

SRI International has used its Short Residence Time-Radiant Coal Flow Reactor (SRT-RCFR) facility to characterize the products and their rates of formation resulting from processing of pulverized coal particles through temperature histories typical of the near-burner flame zone in full-scale coal-fired power plants. Three coals were studied: two high-volatile bituminous (Pittsburgh #8 and Illinois #6) and one subbituminous (Powder River Basin). Tests were conducted at 1,2, and 3 MPa. Stoichiometric ratios were varied to produce conditions from secondary pyrolysis to volatiles burnout, substantial soot burnout, and partial char burnout. The measurements reported here required only relatively small adjustments to the raw data to close the balances on mass and C/H/N within ± 5 % in individual runs. The adjusted datasets show the expected tendency in the burnout of gaseous and solid fuels to increase steadily for progressively more oxidizing conditions. They also show that formation of NOx increases rapidly at stoichiometric ratio (SR) values above 0.5. These data are well suited to serve as benchmarks for development of kinetic models for pyrolysis, gaseous and solid product production and burnout, and pollutant formation, as well as for characterizing char and ash properties. The data have been used to tune chemical submodels that describe evolution of the different species in a manner that can be incorporated into full-scale computational fluid dynamics (CFD) process simulators.