Page 115 - Air pollution and greenhouse gases from basic concepts to engineering applications for air emission control

3.6 Practice Problems 89

Calculate the equilibrium concentrations of NO and NO 2 in ppmv for air that is
held at 1,500 K long enough to reach equilibrium. Given K p for R 1 and R 2 are
−2
1.1 10 −5 and 1.1 10 , respectively.
15. Consider a fuel having formula C 10 H 20 NS is burned completely to CO 2 ,H 2 O,
NO, and SO 2 . Assume that there is no formation of thermal NO. Calculate the
stoichiometric amount of air required in kg of air per kg of fuel.
16. Calculate the equilibrium concentration of sulfur trioxide in ppm when 500 mL
of sulfur dioxide is mixed with 999.500 mL of air. Assume T = 1000K and
P = 2 atm.
17. Calculate the equilibrium concentrations of NO and NO 2 in ppmv from the
following two reactions:

N 2 þ O 2 $ 2NO ð R1Þ

NO þ 1=2O 2 $ NO 2 ð R2Þ

The reactions take place in air at temperature of 2,200 K. Given K p for R1 and
−3 −3
R2 are 3.5 × 10 and 2.6 × 10 , respectively.
18. A car is driven 10,000 miles/year on gasoline. Assume that its milage is 22
miles per gallon (MPG). The gasoline weighs 6.0 pounds/gallon and contains
85 % carbon by weight. Determine the amount of carbon dioxide emitted per
year.
19. Consider constant pressure complete combustion of stoichiometric liquid
butane (C 4 H 10 )-air mixture initially at 298 K and 1 atm. Estimate the AFT.
20. Calculate the stoichiometric air required for the complete combustion of
C 11 H 22 NtoCO 2 ,H 2 O and NO (assuming no thermal NO is formed) in kg of air
per kg of fuel.
21. Under certain conditions, a thermochemical conversion (TCC) process pro-
duced a liquid fuel that contains 80 % by mass carbon and 20 % by mass
hydrogen. This fuel is then burned in dry air at an equivalence ratio of 1.0.
initial temperature of the air–fuel mixture is at T 0 = 298 K and 1 atm.
(a) Determine the formula of this fuel
(b) Determine the AFT assuming complete combustion.
22. Consider combustion of a mixture of 1 mol of CH 4 mixed with air at stoi-
chiometric condition. The flame temperature is measured to be 2,000 K and the
pressure is 1 atm. Assume that only the following gases, CO 2 , CO, H 2 O, H 2 ,O 2
and N 2 , present in product. Determine the mole amount of CO 2 produced
through this combustion process, when only the following two equilibrium
reactions are considered:

CO 2 þ H 2 $ CO þ H 2 O

CO 2 $ CO þ 1=2O 2