The study of environmental considerations on the
mobile phone design in Taiwan
Mei-Yi Tsai, Ding-Ling Huang, Shr-Jiun Wang, Sheng-Lung Lin
Department of Environmental Engineering and Management
Chaoyang University of Technology, Taiwan
168 Jifong E. Rd., WufongTownship, Taichung County, Taiwan 41349
Email Address
Keywords: Life Cycle Assessment, mobile phone, sustainable development
ABSTRACT
This paper presents an LCA framework to analyze the environmental impacts of two designs of mobile phones in Taiwan.A European based methodology, Eco-indicator 95, was used to present the contribution of environmental impacts of the studied targets.The results indicated that the main contributorswere in the use and material processing stages.Comparing the two designs, theenvironmental impacts were estimated an average of 5.8 and 7.2 mPt for classical and fold phones, respectively.
OBJECTIVE
Mobile telephones are the most convenient information exchangetools in Taiwan. According to the survey of Taiwan national communication commission (NCC), the registered numbers of mobile phones reach 24.3 millions in 2007. As shown in the figure 1, the growth rate is about 1.43% annually from 2001 to 2007. For the rule of thumb, the owner in Taiwan may change his/her mobile phone biennially. That causes the great issue on the disposal of old devices. In a view of product life cycle, the different stages of a mobile phone contribute environmental impacts more or less.
Figure 1Registered numbers of mobile phones in Taiwan from 2001 to 2007
. (Source:
From the classical to fold or slide phones, the design of a mobile phone changed quickly.Most of time, the phones were not damaged before they were discarded by owners due to out of fashion. However, there are many small parts in a mobile phone,which are still usable. This consumption pattern increases the complicate in the recycling system. Since 2006, Taiwan environmental protection administration (EPA) has enforced the recycle law for mobile phones. It was recognized only 68% of recycling rate for discarded phone in 2007. The improvement of the local recycling system should be considered. Some issues are raised. Is there any concern for the dismantling recyclers to participate the system? What are the roles of the developers to design environmental friendly phones for consumers? What will be the environmental considerations of the mobile phone that consumers concern? To answer the questions, it needs a systematic analysis of environmental considerations of mobile phones.
The requirement of green design becomes more popular in the market. In this study, two types of the mobile phones, i.e., classical and fold, were selected to evaluate their potentials of environmentally friendliness. We tried to compare the environmental performance between these phones using life cycle assessment (LCA). The results of the simulation could tell us the hot environmental spots of the mobile phones. The information is good for the design of a new phone. On the other hand, the considerations of the recycling systems of mobile phones were also important to save the consumption of resources.
METHODOLOGY
1. Goal and Scope
A complete life cycle of a mobile phone is defined as the stages in figure 2. A mobile phone is manufactured in the plant while its components were from the upstream factories, such as the frame, vibrator, screw, antenna, PE, rubber, PS, battery, casing, LCD, spherical lens, PCB, and soft PCB.The down streaming stages include distribution, use, and treatment/recycling. The environmental performance per mobile phone was selected as the function unit of the study.The phone should meet the requirements of the GSM standards and have two years of life before it is discarded.
The most parts of mobile phoneswere assumed to be produced in Taiwan and the transportation of the parts to assembling factories was ignored. The mobile phones were manufactured in Taiwan because there are many international outsourcing factories located here. The products were delivered and used in the island. After the end of life, the phones were collected and recycled in the local system due to the law of Taiwan EPA.
Figure. 2 The scope of an LCA study for a mobile phone
2. Life Cycle Inventory
In the inventory phase, we need to build up the input data, which are used in the LCA model. There are two basic data sheets usually required. One is the mass balance sheet to determine all elementary flows in the procedures. The other is the sheet of the scenario assumptions. The formers show the data collected directly from inventory. The latter are those calculated from indirect collected data. Tables 1 and 2 present the input data of the classic mobile and fold mobile phones,respectively.The data was collected by dismantling eleven phones and weighing the parts. These phones were grouped into two designs. However,the energy consumption in the manufacturing stage was from the communication with the manager of local factory [1].
3. Scenario Assumptions
The data, which could not collected from the manufacturers, such as the data of use and disposal of, are calculated by the scenario assumptions.In the use stage, most consumers are registered in the programs by Chunghwa Telecom of Taiwan and the average expenditure is about 9,600 NTD annually. It calculated that the energy consumption is 8.04 kWh per phone in its life time of 18 month.The transportation of the distribution was assumed as 150 km based on the average distance of the island. The disposal scenario is 68% recycled and 32% landfilled due to the Taiwan EPA’s report.
Table 1. The input data of a classic mobile phone
Life cycle stage / Item / Quantity(Unit)Material
Processing / Total weight / 97.02 g
Frame-Steel / 4.58 g
Vibrator-Al、Mg / 4.45 g
Screw-Electro steel / 0.76 g
Antenna-CrAl、Si、Steel / 1.27 g
PE / 1.34 g
Rubber-SBR、Epoxy resin / 4.14 g
IC-Zn、Cd / 11.53 g
Battery-Li / 21.19 g
Casing-PE / 35.05 g
STN-LCD-NaOH、Ethylene oxide / 12.29cm2
Spherical lens-Glass / 0.11 g
PCB- Epoxy resin、Cu、Cl、NaCl / 9.65 g
Manufacturing / Electricity / 1.6 kWh
Distribution / Portage-Truck 16t / 19.03 kgkm
Use / Electricity / 6.94 kWh
Disposal / Recycling / Landfill / 32 %
Recycling / 68 %
Table 2.The input data of afold mobile phone
Life cycle stage / Item / Quantity(Unit)Material
Processing / Total weight / 95.15 g
Frame-Steel / 7.70 g
Vibrator-Al、Mg / 2.74 g
Screw-Electro steel / 0.56 g
Antenna-CrAl、Si 、Steel / 2.30 g
PE / 0.47 g
Rubber-SBR、Epoxy resin / 0.24 g
Foamrubber-PS / 0.08 g
IC-Zn、Cd / 10.62 g
Battery-Li / 15.31 g
Casing-PE / 36.43 g
STN-LCD-NaOH、Ethylene oxide / 18.30cm2
Spherical lens-Glass / 1.84 g
PCB-Epoxy resin、Cu、Cl、NaCl / 10.41 g
Soft PCB-Cu、HCl、H2SO4、NaOH / 13.16 cm2
Manufacturing / Electricity / 1.6 kWh
Distribution / Portage-Truck 16t / 19.0292 kgkm
Use / Electricity / 8.04 kWh
Disposal / Recycling / Landfill / 32 %
Recycling / 68 %
RESULTS AND DISCUSSIONS
The data collected in the inventory phase were input into a software SimaPro 7. The Eco-indicator was selected as the impact assessment method. The environmental impacts are grouped into greenhouse effect, ozone layer depletion,acidification, eutrophication,heavy metals,carcinogenity,winter smog, summer smog, pesticides,energy resources depletion, and solid wastes categories.
1. Life Cycle Impact Assessment
Figure 3 indicates the results of the simulation for a classical phone. The main contributions of the ozone layer depletion, heavy metals, carcinogenity, summer smog, and solid wastes are from the material processing stage. The impacts of greenhouse effects, acidification, eutrophication, winter smog, and energy resources are from the use stage. The use of the energy in the phone caused 79% of the greenhouse effects and 83% of energy resource depletion in the phone life cycle. The impact of the ozone layer depletion is from the cleaning processes of the parts.In the recycle stage, many wasted materials could be used in the secondary market in additional to the reuse of dismantled parts. These materials include plastic cases, copper, gold, as well as the precious metals.
Figure 3. The distribution of environmental impacts for a classic mobile phone during its life cycle
For the fold phones, the result of the simulation is shown in the figure 4. The distribution of the environmental impacts is similar to those in the classical phones, but there exists some difference. It is found that the parts used in the fold phone are more than the classics.
Figure 4.The distribution of environmental impacts for a fold mobile phone during its life cycle
2. Interpretation
In order to compare the environmental impacts caused by two models, the Eco-indicator method, based on the European scale, was employed. The Eco-indicator is expressed in mPt or Pt per functional unit. The estimated eco-indicator scores are presented in the figures 5.The classical phone had a total score of 5.7 mPt, while the fold one had 7.0 mPt. It concluded that the environmental impact of the fold phone is higher than that of the classic design in the view of total life cycles.However, the main contributors of two designs are from the use and material processing stages.For fold design, they contributed ??% and ??% eco-indicators in the use stage and the material stage, respectively. For classic design, they contributed ??% and ??% eco-indicators in the use stage and the material stage, respectively.
Figure 5.The environmental impact of the classic and fold mobile phone system from cradle to grave
3. Improvement
From the LCA study, it can be recognized that the environmental impacts of two phone designs were low in their life cycle. The main contributors were from the use and material processing stages. As seen in Figures 6, the analyses of the parts showed that the major environmental impact was from PCB. For classic phones, the impact was estimated an average 1.8 mPt with the range of ??~??, while the number was 2.0 mPt with the range of ??~?? for the fold ones. These PCBs contained the heavy metals and contributed high impacts.
The other hot environmental spot of thefold mobile phones was from the heavy metals of soft PCB.The reduction of heavy metals becomes more important in the design of phones. If it could not reach, the improvement of recycling heavy metals in mobile phones should be conducted.In the use stage, the energy saving models can improve the performance of the phones, both in the economic and environmental ones.
Figure6.The environmental impacts for different parts in thefold and classical mobile phone
CONCLUSION
From the study, it could conclude that the environmental impacts of both phone designs were not much. The main contributors of environmental impacts are from the use and material processing stages. The opportunity to improve environmental performance of a mobile phone may direct to the energy saving design and use hazardous materials as less as possible.On the other hand, since Taiwan EPA has enforced the recycle of discarded phones, the designs of mobile phones could direct to easy to disassemble and increase the recycle rate. The consumers should have the rights to know which mobile phones are more environmental friendly and the local authorities should ask the manufacturers to give the information. A LCA study of products can be used to evaluate the environmental considerations of mobile phones.
REFERENCES
[1]Wei,J.F., (2005),“The Life Cycle Assessment of Mobile phones”, Thesis, Chaoyang University of Technology, Taiwan, pp.115-121.