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How are the composition and quantity of combustion products calculated?

  1. Main products of theoretical complete combustion (trace species ignored)
  • CO2CO_2 from carbon
  • H2OH_2O from hydrogen and fuel moisture
  • SO2SO_2 from sulfur
  • N2N_2 from air and fuel nitrogen
  • If α>1\alpha>1, excess O2O_2
  1. Calculation from elemental analysis (kmol/kg fuel)
    Let elemental mass fractions be C,H,O,S,NC,H,O,S,N (kg/kg):
  • nCO2=C12n_{CO_2} = \dfrac{C}{12}
  • nH2O=H2+W18n_{H_2O} = \dfrac{H}{2} + \dfrac{W}{18} (if fuel moisture WW is included, kg/kg)
  • nSO2=S32n_{SO_2} = \dfrac{S}{32}
  • Theoretical oxygen: nO2,0=C12+H4+S32O32n_{O_2,0} = \dfrac{C}{12} + \dfrac{H}{4} + \dfrac{S}{32} - \dfrac{O}{32}
  • Nitrogen from air: nN2,air=0.790.21(αnO2,0)n_{N_2,air} = \dfrac{0.79}{0.21}\,(\alpha n_{O_2,0})
  • Fuel nitrogen to nitrogen: nN2,fuel=N28n_{N_2,fuel} = \dfrac{N}{28}
  • Excess oxygen: nO2,ex=(α1)nO2,0n_{O_2,ex} = (\alpha-1)n_{O_2,0}

Dry flue gas (no water):

  • ndry=nCO2+nSO2+nN2,air+nN2,fuel+nO2,exn_{dry} = n_{CO_2} + n_{SO_2} + n_{N_2,air} + n_{N_2,fuel} + n_{O_2,ex}

Standard-state volume:

  • V=22.414 nV = 22.414\ n (m^3/kg)