Life-cycle Analysis on Acid-gases Emissions of the Lightweight to Passenger
Cars Using Aluminum Alloy and Advanced High Strength Steel
Li-sa Zhu 1
1
School of Applied Science, JiLin teacher's Institute of Engineering and Technology, Changchun, China
Abstract – Nowadays, in order to reduce fuel
consumption and tail gas emissions, the lightweight has been
adopted in passenger cars. However, whether the fuel
consumption and tail gas emissions including acid-gas can be
reduced must be calculated from life-cycle. In this paper,
acid-gas emission of normal and modified passenger cars has
been calculated in life-cycle and more detailed stages on
acid-gas emission have been analyzed.
Keywords –passenger cars, the lightweight, acid-gas, lifecycle
I. INTRODUCTION
In China, the population of passenger cars (PPC) has
been increasing with drastic speed. In 1960, the PPC was
only 230,000; and in 2000, the PPC has been reached
11,270,000 and almost has been increased by 50 in 40
years. Five years later, the PPC were nearly double and
arrived at 20,500,000. In 2010, the PPC hit a new high
and arrived at 62,040,300. It was estimated that the PPC
will exceed 100 million in 2020.
With the wide use of passenger cars and the
tremendous PPC, much acid-gas emissions have been
emitted during the using of passenger cars. Supposing that
a passenger car has been drive 10,000(km/year) and drive
100 thousand kilometers before scrapping; and the
amount of SO2 are 0.295(kg) in one year and 2.95(kg)
before scrapping. So In 2010, the SO2 emissions by the
PPC were 1802 (ton). SO2 is a main acidification gases, it
can form acid rain and destroy building, forest and crops.
Besides SO2, there are also a lot of acid gases in passenger
cars tail gases such as NO2 and NOx.
Based on mentioned above, the acidification caused by
the PPC was very critical. So in order to reduce
acidification gases, the lightweight to passenger cars has
been adopted. The lightweight can reduce curb mass, oil
consumption and acid-gases emissions of using stage, but
acid-gases also have been emitted during other stages
such as mineral mining, materials producing, and products
manufacturing stages. So the analysis on acid-gases
emissions must be considered from life-cycle, which will
give the proper conclusions.
II. LITERATURE REVIEW
With the research progress of lightweight (LW) to
passenger cars/vehicles, environmental, energy and
economic issues aroused by LW have been studied. Kim
Hyung-Ju et al. (2011) provided an assessment of vehicle
LW with aluminum and high strength steel (HSS), and the
assessment results show greater GHG savings derived
from greater LW and added manufacturing costs as
expected [3]. Kim Hyung-Ju et al. (2010) compared the
increase in greenhouse gas (GHG) emissions associated
with producing LW vehicles with the saved emissions
during vehicle use, and calculated that how many years of
vehicle use are required to offset the added GHG
emissions from production stage, and the result show
payback periods for HSS are shorter than for aluminum [4].
Kang, Yong-Lin et al. (2008) pointed out that the
development and application of advanced high-strength
steels (AHSS) for automobile LW not only brings about
significant emissions reduction and energy-saving, but
also has advances of improved safety as well as recycling
and reutilization [5]. Waurzyniak and Patrick (2009) have
given the result that advanced materials for automotive
manufacturing are helping automakers build lighter, more
fuel-efficient vehicles, and related advanced materials
property, including AHSS, HSS and aluminum, has been
given [6][7]. Masataka Hakamada et al. (2007) have given
these conclusions that magnesium substitution can save
more life cycle energy consumption than the Al
substitution, although magnesium ingot production
consumes more energy than aluminum and steel
productions; The use of recycled magnesium ingot in a
high weight ratio is needed in keeping the life cycle
energy consumption and CO2 emissions low; Strength
improvement in the magnesium alloy decrease total
energy consumption and CO2 emissions; if the body and
hood are made of magnesium alloy and the ratio of
recycled ingot is sufficiently high, the total energy
consumption and CO2 emissions will be markedly
reduced [8].
From related articles mentioned above, the deeper
studies upon LW to passenger cars/vehicles of energy and
environment have been made. But acid-gas emissions
were few studied.
III. METHODOLOGY
The proposed analysis method consist three steps:
They are goal and scope definition, calculation model
establishment, data collection. Particulars of each step are
shown below.
A. Step 1: goal and scope definition
In this step, a life cycle assessment application has
been used to study acidification of the lightweight to
passenger cars. The scope of this step is to calculate
acidification of the lightweight to passenger cars in life
cycle; and scope definition is divided into five stages:
1. Mineral mining stage;
2. Materials producing stage;
3. Products manufacturing stage;
4. Transporting stage;
5. Using stage.
In this paper, transporting stages only included
materials transporting stage between different enterprises.
So the acidification produced in internal enterprises was
neglected [9].
B. Step 2: calculation model establishment
In this paper, acidification calculation model has
been established as below [11][12]:
Acid total   Acid i
(1)
Where Acid is acidification of the lightweight to
passenger cars in life-cycle;
i is from mineral stage to using stage.
C. Step 3: data collection
In this paper, four evaluating projects were
constructed. They main parameters and acidification data
are calculated by equation (1) and shown as table 5 [13- 15].
For the paper limited, only the detailed input and output
data of project 1 and project2 were listed in this paper.
Table II
Main technologic and economic parameters of H passenger cars
Model
Curb
mass
(kg)
Crew
size
(person)
Oil
consumption
(L/100km)
4×2
Frontengine
Frontdrive
1300.
00
5.00
13.00
Material
structure
Steel
Iron
70
TABLE II
PROJECT 1 INPUT/OUTPUT (695KG PRIMARY HIGH STRENGTE STEEL BODY)
Stages in life cycle
Regular
Unit
Mineral mining
Input
Output
Iron ore
Scrap
Manganese
Limestone
Dolomite
Fluorite
Iron mud
Water
Diesel fuel
Gasoline
kg
kg
kg
kg
kg
kg
kg
kg
kg
kg
Nature gas
CO2
CO
SO2
NOx
CxHy
HC
Dust
H2S
m3
kg
kg
kg
kg
kg
kg
kg
kg
N2O
kg
241
9.4
1.87
615.07
301.21
41.08
19.63
13.85
198.76
Materials
producing
16503
196
113
384
666
5
219
281625.58
4.27
3958.65
35.08
35.08
3369.68
499.20
11.30
266.24
1.10
Product
manufacturing
Transporting
123956.15
7
8.20
0.94
76.71
454
0.02
0.02
2.47
0.04
263
1829.98
0.15
0.15
30.32
0.08
Using
21497.16
68835.4
5011.06
5011.06
625.64
987.39
9.77
TABLE III
PROJECT 2 INPUT/OUTPUT (375.3KG PRIMARY ALUMINUM BODY)
Stages in life cycle
Unit
Mineral mining
Input
Bauxite
Soda ash
Limestone
Anthracite
Baking soda
Bay red mud
kg
kg
kg
kg
kg
kg
Materials
producing
6831
195
891
128.50
41
2680.88
Product
manufacturing
Transporting
Using
30
Stages in life cycle
Unit
Mineral mining
kg
kg
kg
kg
kg
kg
kg
kg
kg
kg
kg
kg
kg
m3
KW.H
kg
kg
kg
kg
kg
kg
74.22
53.5
896.80
75
561.69
201.25
20027.81
434.48
95.09
0.12
0.12
0.48
0.01
5923.66
490.12
108.78
54.06
0.22
407.56
0.02
0.48
2.21
0.06
HC
kg
0.02
PM
kg
0.02
HF
kg
17.30
Dust
kg
42
Table V ACIDIFICATION（SO2.EQ KG） DATA of EVALUATING
PROJECTS*
MM
MP
PM
T
U
Total
Project 1
54.82
2417.94
24.57
2.27 446.70
2946.30
Project 2
0.46
146.62
2.03
1.72 348.64
499.70
Project 3
5.98
2.03
0.42 348.64
357.07
Project 4
42.41
129.19 1.01 405.64
988.25
*MM is mineral mining stage;
MP is materials producing stage;
PM is product manufacturing stage;
T is transporting stage;
U is using stage.
In table.2, project 1 is basic passenger car, which body
in white (BIW) was made by high strength steel (HSS)
and curb mass is 1300.00 (kg).
Project 2, 3, 4 are modified passenger cars, whose
BIW were replaced with primary aluminum alloy,
recycled aluminum alloy and advanced high strength steel
and curb mass were 980.3(kg), 980.3(kg) and 1166.40(kg)
respectively. Oil consumption of using stage is calculated
by equation (2).
Gasoline  M  (L/100km)
(2)
Where
  8.072 ;
  1.019 .
Product
manufacturing
Transporting
Using
344.72
0.015
0.41
1.87
0.03
16775.74
53717.07
3910.48
6.88
488.23
770.53
6.33
Total
Using
Projects
Output
Carbon pole
Cryolite
Aluminum fluoride
Calcium fluoride
Magnesium fluoride
Nacl
KCl
Water
Diesel fuel
Anthracite
Datong system of coal
Matellurgical coke
Heavy oil
Nature gas
Electricity
Gasoline
CO2
CO
SO2
NOx
CxHy
Materials
producing
759
22.10
35
4.10
5.50
27
27
41068
Transporting
Production
manufacturing
Materials
producing
Mineral mining
0
500
1000
1500
2000
2500
3000
3500
Acid-gass emissions(SO2.eq)
Project 1
Project 2
Project 3
Project 4
Fig.1 Acid-gas emissions of projects
IV. DISCUSSIONS: EFFECTS OF DIFFERENT
MATERIALS AND USING DISTANCE
This part included three contents: Effects of primary
aluminum; Effects of recycled aluminum; Effects of
advanced high strength steel (AHHS).
A. Effects of primary aluminum
Compared with normal project1, project2'BIW were
replaced with primary aluminum and its life-cycle acidgases emissions were reduced from 2946.30(SO2.eq kg) to
499.70(SO2.eq kg). That mainly because that acid-gases
emissions of project2 were extremely reduced in materials
producing stage. Concrete details were shown as fig.2.
amount of acid-gases emission is higher in using stage;
3000
450
400
2500
350
2000
300
acid-gases amonut 1500
250
1000
200
500
150
100
0
MM
MP
PM
T
U
Total
50
Life-cycle Stages
0
Project 1
Project 2
Project 1
Project 2
Project 3
Project 4
PM
24.57
2.03
2.03
129.19
U
446.7
348.64
348.64
405.64
Fig.2 Acid-gases amount between project1 and project2
B. Effects of recycled aluminum
Compared to primary aluminum, at materials producing
stage, recycled aluminum can extremely reduce acidgases emissions. But recycled aluminum has less effect on
total acid-gases emissions in life-cycle of passenger cars.
That mainly because the acid-gases emissions of using
stage dominates the life-cycle acid-gases emissions.
As in developed countries, the ratio of recycled
aluminum has surpassed 50%. So in this paper, six
recycled ratio of aluminum have been considered, they
were 50%, 60%, 70%, 80%, 90%, 100% and details data
were shown as Fig.3.
Fig.4 The amount of acid-gases in product manufacturing and using
stages of all projects
and the amount of acid-gases emissions in product
manufacturing is the highest in all projects. The specific
results were shown as Fig.4.
D. Effects of USING DISTANCE
As to the most acid-gases emissions are emitted during
using stage, it is essential to consider the effects of using
distance. In this paper, the using distance is 200,000(km),
and the sensitivity analysis of per 10,000 (km) must be
calculated.
3500
700
3000
600
2500
500
2000
400
1500
300
1000
200
500
100
80
SO2.eq kg
70
60
50
40
0
10
15
20
1E+4km
20
Project 1
Project 2
Project 3
Project 4
Fig.5 Sensitivity analysis of Acid-gases emissions
10
0
0
5
30
50%
60%
70%
80%
90%
100%
76.3
62.24
48.17
34.11
20.04
5.98
Fig.3 Effects on acid-gases emissions of recycled aluminum ratio
From Fig.3 that if the ratio of recycled aluminum can be
reached 70%, the amount of acid-gases emissions in
materials producing stage can be reduced 98.45(SO2.eq kg)
and if the ratio is reached 100%, in materials producing,
amount of acid-gases also can be arrived at “zero”.
C. Effects of AHHS
From table.5, due to adopted AHHS, the amount of acidgases on project2 was second in all projects. That mainly
due to the density of AHHS is higher than neither primary
aluminum nor recycled aluminum alloy, which led to the
From Fig.5, the sensitivity analysis results are as same as
the life-cycle, that only because compared to using stage,
the acid-gases emissions, in mineral mining, materials
producing, product manufacturing and transporting stage,
are very few.
V. CONCLUSIONS
From these studies, main conclusions have been
achieved from life cycle as follows:
1. The acidification emissions of project 1 is the most
in all projects, that means basic passenger cars emit acidgas amount is bigger than modified passenger cars. That
mainly due to basic passenger cars emitted more acid-gas
in materials producing stages and should be given ample
attention;
2. Applying recycled aluminum alloy can extremely
reduce acid-gas emissions than primary aluminum alloy.
That mainly due to acid-gas emissions can be reduced in
materials producing stages by using recycled aluminum
alloy. So in order to reduce acid-gas emissions, the ratio
of recycled aluminum alloy must be height.
Nowadays, the ratio of recycled aluminum alloy has
been arrived at 50% to 60% in developed countries, and
the ratio is very poor in developing countries. So the
potential of improving recycled ratio of aluminum is very
tremendous in the word. If the conditions are permitted,
the mechanism of recovering scrap aluminum should be
built.
3. The acid-gas emissions of using AHHS is higher
than using neither primary or recycled aluminum alloy,
and that due to acid-gas emissions is higher in production
manufacturing and using stages.
Detailed results and conclusions have been shown as
Figure 1.
VI. ACKNOWLEDGEMENT
This paper was supported by the outline of the eleventh
five-year scientific and technological plan of Jilin
province education department [No.2009 (279)].
VII. APPENDIX
A. Ingredient of tail gas
Table VI Main ingredient of tail gas (g/L)
Ingredient
Weight
CO2
2321.5
SO2
0.295
CO
169.0
NOx
21.1
33.3
CxHy
B. Acidification potential
Ingredient
SO2
SO3
NO2
NOx
NO
HNO3
NH3
HF
H2S
HCl
H2SO3
H3PO4
Weight
1
0.8
0.7
0.7
1.07
0.51
1.88
1.6
1.88
0.88
0.65
0.98
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