Emissions - Decreasing Fuel Consumption and Exhaust Gas Emissions in Transportation - page 79

Chapter 5
Emissions

Transportation produces exhaust gas emissions. The products are gases, particles,
noise, and heat. However, pollutants can be emitted not only by engines but also
by other devices such as fire extinguishers, fuel tanks, and refrigerators on vehi-
cles, airplanes, and ships. Most emissions are produced by the burning process in
internal combustion engines [ 1 ].
Combustion produces several types of substances, which intensively influence
the atmosphere [ 2 ]. Diesel and kerosene contain approximately 85% carbon and
15% hydrogen [ 3 ], petrol has a higher concentration of hydrogen. They theoreti-
cally burn according to the equations [ 4 ]:

12 kgC þ 32 kgO 2 ! 44 kgCO 2 þ 407 ; 500 kJ ð 5 : 1 Þ

4 kgH þ 32 kgO 2 ! 36 kgH 2 O þ 481 ; 500 kJ : ð 5 : 2 Þ

5.1 Physical and Chemical Properties
of Combustion Products

The main products of combustion are CO 2 and H 2 O:

CH 4 þ 2O 2 ! CO 2 þ 2H 2 O : ð 5 : 3 Þ

The CO 2 emissions from human activities are approximately (21.00-

25.00) 9 10 9 t year -1 , i.e., (46.26-55.07) 9 10 12 lb year -1 . Transportation emits

approximately

1 = 3

of the whole CO 2 emissions on the Earth, i.e., (8.5-

9.0) 9 10 9 t year -1 , i.e., (18.72-19.82) 9 10 12 lb year -1 [ 5 ].
The combustion of 1.0 kg of pure carbon produces 3.67 kg, i.e., 8.10 lb of CO 2 .
Burning 1 kg, i.e., 2.208 lb gasoline produces 2.9 kg, i.e., 6.402 lb of CO 2 . Burning