Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Role of char during reburning of Nnitrogen oxides. Second quarterly report, 1996

Technical Report ·
DOI:https://doi.org/10.2172/622608· OSTI ID:622608
 [1];  [2]; ;  [1];  [2]
  1. Mississippi Univ., University, MS (United States)
  2. Kansas State Univ., Manhattan, KS (United States)
Reburning is an emerging three-stage combustion technology designed for the reduction of NO by introducing a small amount of reburning fuel above the primary flame where the majority of NO is chemically reduced to nitrogen. While coal, in general, has not been considered an effective reburning fuel, research at the University of Mississippi suggested that lignite has a reburning efficiency even higher than that of methane. Furthermore, heterogeneous mechanisms are more important than homogeneous mechanisms for char/NO reaction. The objectives of this research are to investigate: (1) implications of pore structure analysis, (2) parameters governing heterogeneous reactions, and (3) estimation of rates of NO reduction and mass transfer limitations. Experiments have been performed in a flow reactor with a simulated fuel gas at a stoichiometric ratio (SR) 1.1. Reburning fuels in this study include chars derived from Pittsburgh No.8 bituminous coal and Mississippi lignite. Chars were produced in N{sub 2} by suspending a sample basket in a tube furnace. Pore structure analyses include BET-N{sub 2}, BET-CO{sub 2}, and DR-CO{sub 2} surface pore size distribution, micropore volume, total pore volume, and average pore radius. These studies suggest that neither BET-N{sub 2} nor DR- CO{sub 2} surface area is a normalization factor of chars of different origin. Reaction with NO leads to closures of pores, which may be contributed by formation of surface complexes.
Research Organization:
Mississippi State Univ., University, MS (United States). Dept. of Chemical Engineering; Kansas State Univ., Manhattan, KS (United States). Dept. of Chemical Engineering
Sponsoring Organization:
USDOE Assistant Secretary for Fossil Energy, Washington, DC (United States)
DOE Contract Number:
FG22-93PC93227
OSTI ID:
622608
Report Number(s):
DOE/PC/93227--T11; ON: DE97054568
Country of Publication:
United States
Language:
English