Fuels and Combustion - University of Tulsa

3.6 Write the balanced reaction equation for the complete combustion of ethane, C 2H 6,
in air. What are the mass and mole fractions of fuel, air, oxygen, and nitrogen in the
reactants? What are the mass and mole fractions of carbon dioxide and water vapor in
the combustion products?
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3.7 Write the balanced reaction equation for the complete combustion of propane,
C 3H 8,, in air. What are the mass and mole fractions of fuel, air, oxygen, and nitrogen in
the reactants? What are the mass and mole fractions of carbon dioxide and water vapor
in the combustion products. What are the mass and mole air-fuel ratios?
3.8 Write the balanced reaction equation for the complete combustion of C 8H 18 in air.
What are the mass and mole fractions of fuel, air, oxygen, and nitrogen in the reactants?
What are the mass and mole fractions of carbon dioxide and water vapor in the
combustion products? What are the mass and mole air-fuel ratios?
3.9 Gasoline, sometimes represented as C 8H 18, is burned in 25% excess air mass. What
are the mass and mole stoichiometric and actual air-fuel ratios? Determine the mass
and mole fractions of the combustion products.
3.10 Determine the lower and higher heating values of methane using the JANAF table
of heats the formation.
3.11 Determine the as-fired stoichiometric and actual air-fuel ratios for Greene,
Pennsylvania raw coal (Table 3.3) with 5% moisture and the mass and mole flue gas
compositions for combustion with 20% excess air.
3.12 Compare the stoichiometric and actual air-fuel ratios and the mole flue gas
composition for combustion with 20% excess air for the following raw and clean
(process #1) coals (Table 3.3): (a) Freestone, Texas, big brown lignite; (b) Indiana,
Pennsylvania, Freeport (upper); (c) British Columbia, Hat Creek (A zone); (d) Perry,
Illinois no. 6; (e) Muhlenberg, Kentucky no. 9; (f) Nicholas, West Virginia, Kittanning;
(g) Belmont, Ohio, Pittsburgh; (h) Big Horn, Montana, Robinson; (i) Greene,
Pennsylvania, Sewickley; (j) Kanawha, West Virginia, Stockton-Lewiston; (k) Belmont,
Ohio, Waynesburg.
3.13 If Union, Kentucky no. 11 raw coal has 10% moisture, as mined, determine the asmined
proximate and ultimate analyses for this coal.
3.14 If Big Horn, Montana, Robinson raw coal has 15% moisture, as-mined, what are
its as-mined proximate and ultimate analyses?
3.15 Determine the ultimate analyses of the raw coals listed in Exercise 3.12 (a-e)
assuming 10% as-mined moisture.