Emissions - Decreasing Fuel Consumption and Exhaust Gas Emissions in Transportation - page 80

1 kg diesel fuel or kerosene emits approximately 3.15 kg, i.e., 6.95 lb of CO 2 .
Conversion from mass to volume depends on density. 1 l of gasoline produces
about 2.32 kg, i.e., 5.11 lb CO 2 . Burning 1 l of diesel fuel or kerosene emits about
2.32 kg, i.e., 5.11 lb of CO 2 . 1 l of liquefied petroleum gas emits 1.8-2.0 kg, i.e.,
3.96-4.41 lb CO 2, depending on the proportion of C to H atoms in the fuel [ 6 ].
The fuel consumption of 5.6 l 9 (100 km) -1 , i.e., 0.305 gal mi -1

(US) or

0.41 gal mi -1 130 g km -1 , (UK) petrol results in the emission of i.e.,

4.585 oz km -1 or 7.384 oz mi -1

CO 2 . This is the current European level for car

emissions in NEDC [ 7 ].
Burning 1 t diesel fuel or kerosene emits 1.24 t, i.e., 2 733 lb of water vapor.
Emissions of H 2 O vapor on the Earth are much higher than the CO 2 emissions, due
to the large surface of the oceans but water vapor does not negatively influence the
climate, with the exception of the emissions of airplanes at higher altitudes [ 8 ].
In practice, a small volume results in not completely burned end products of
oxidation, such as CO and several hydrocarbon (HC) substances or oxidation
products made of atmospheric nitrogen, such as NO and NO 2 . Substances such as
CO, HC, NO, NO 2 , and SO 2 are pollutants and dangerous to human health. They
are not stable products because OH radicals change them from their intermediate
state to end products in the atmosphere:

CO þ OH ! CO 2 þ H : ð 5 : 4 Þ

A modern self ignition engine combusted by diesel fuel and a jet engine com-
busted by kerosene produce on average 3 kg (6.6 lb) of CO per 1.0 t (2,204 lb) of fuel
[ 9 ]. Depending upon the type of internal combustion engine and the range of use, the
value varies between 1.1 kg (2.4 lb) and 8.7 kg (19.2 lb). Global human CO emis-
sions amount to approximately 1,077 9 10 6 t (2,372 9 10 9 lb) per year [ 10 ].
Transportation emits approximately one-fifth of the total CO amounts.
Unburned HCs are the ultimate products of combustion and can react to
intermediate and later to heterocyclic aromatic organic substances, which are
carcinogenic:

CH 4 þ OH ! CH 3 þ H 2 O : ð 5 : 5 Þ

Self ignition and jet engines emit approximately 0.7 kg (1.5 lb) of unburned
HCs per 1.0 t (2,204 lb) of fuel on average. The mass varies between 0.1 kg
(0.22 lb) and 3.5 kg (7.7 lb) [ 11 ]. The amount of world anthropogenic HC pro-
duction is approximately 275 9 10 6 t (606 9 10 9 lb) per year.
Depending on the quality of combustion, between 6 kg (13.2 lb) and 20 kg
(44.1 lb), on average of 14.7 kg (32.4 lb) of NO per 1.0 t (2,204 lb) fuel is
produced, mainly due to the high temperatures in the combustion zone where the
nitrogen molecule dissociates and finally oxidizes [ 12 ]:

O 2 þ N ! NO þ O :

ð 5 : 6 Þ

195 9 10 6 The annual global NO x (NO plus NO 2 ) emissions are t i.e.,

430 9 10 9 lb. Most of them (156 9 10 6 t, i.e., 338 9 10 9 lb) are caused by