LCA of scrap CRT display at various scenarios of ...

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Procedia Environmental Sciences 16 (2012) 576 – 584

The 7th International Conference on Waste Management and Technology

LCA of scrap CRT display at various scenarios of treatment Ruxuan Niua, Zhishi Wanga, Qingbin Songa, Jinhui Lib, a

Faculty of Science and Technology, University of Macau, Macau, China b School of Environment, Tsinghua University, Beijing, China

Abstract With the development of the science, technology and economy, electronic products became the important necessary products in daily life. Due to the large usage of electronic products, generation of the e-waste became more and more. The e-waste treatment was generally as a troublesome task. The life cycle assessment (LCA) method is used to analyze the treatment technology of cathode ray tube (CRT) display. The results show that the environmental impact of incineration of CRT display has the greatest impacts, with comparison to the manual-based dismantling and mechanical recycling. The impact of Carcinogens is the major contributor, which cause a direct impact on human health. The result suggests that the CRT display should be separately treated and not be mixed with municipal solid waste which is treated by incineration. © 2012 The Authors. Published by Elsevier B.V. © 2012 Selection and/or peer-review under responsibility of Basel Convention Coordinating Centre for Asia and the Pacific Selection and/or peer-review under responsibility of Basel Convention Coordinating Centre for Asia and the Pacific and National Center of Solid Waste Management, Ministry of Environmental Protection of China. and National Center of Solid Waste Management, Ministry of Environmental Protection of China Keywords: E- waste; CRT display; End-of-Life; LCA

1. Introduction As the economic development and technological progress, all kinds of high-tech electronic products not only bring convenience and pleasure to us, but also produce an electronic waste [1]. A huge amount of electronic waste causes serious harm to humans and the environment. Display has been widely used in the production and life of the people and has been as the core of the TV, computers, oscilloscopes and other electrical and electronic equipment, it is due to the advantages of mature technology, high reliability, cheap and long life.[2]Since 2003, it is estimated that China has over 500 million TVs need to be wasted per year. Along with the move to the information society, there is about over 30 million computers going to home per year. If the scrap CRT display do not have properly handled, the resource would not has the comprehensive utilization and environment also has accepted the adverse effects. CRT display has the

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1878-0296 © 2012 Selection and/or peer-review under responsibility of Basel Convention Coordinating Centre for Asia and the Pacific and National Center of Solid Waste Management, Ministry of Environmental Protection of China doi:10.1016/j.proenv.2012.10.079

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main component of leaded glass, copper, iron, aluminum, plastic, and some trace elements in the rare earth metals such as phosphor. These substances in common CRT displays of the content of Table 1 [3]. After the computer is scraped, if these substances have not been reasonable treated, it has great harm to the environment. For example, a CRT display contains about 1kg of lead, it is mainly in the display glass. If disposed these waste glass by landfill, lead and heavy metals in the waste glass will slowly infiltrate into the soil, The lead will be greatly increased in the soils of various plants (including food); it is general harm to the human body include: damage to central and peripheral nervous system, circulatory system and kidneys; affect the endocrine system; serious impact on the brain development, particularly serious harm to children, etc [4]. Many organic materials used in computer manufacturing (including plastic) must has the bechlorinated, brominated and sulfonated process, if these materials are simple incinerated, then dangerous amounts of exhaust gas can be released, the formation of acid rain also can damage the ozone layer [5]. Other computer-related components in the presence of cadmium, mercury, barium, chromium, titanium and other metals caused the environment pollution as serious as lead. Table 1 Substance of the main components in Common CRT Display

Composition

Leaded Glass

Steel, Iron

Plastic

Copper

Aluminum

Rubber

Other

Content 46.3 30.5 18.7 3.1 2.2 1.6 0.2 ˄%˅ As the rapid development of new display devices, the traditional CRT market is general shrinking, according to the current developed trend, the CRT will be eventually replaced by new types of displays. How to dispose of CRT products to achieve the recycling is becoming an emerging research topic. Scrap CRT display have the following treatment techniques: (1) recycling, remanufacturing CRT glass; (2) foam glass production; (3) for metallurgical flux andrefining of lead; (4) landfill disposal; (5) concrete aggregate; (6) clay, ceramic flux, glaze; (7) glass tiles (mainly nonpb -screen glass); (8) will smash the glass CRT display (broken glass) for road construction; (9) hazardous waste (mainly nuclear waste, etc.) of packaging materials, radiation shielding devices; (10) in the aircraft manufacturing industry of glass (windshield) to serve as raw materials. "Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal" made more comprehensive provisions on transboundary movements and disposal of electronic waste and hazardous waste. CRT glass is listed in Annex VIII clause in the list A, A2010, and is limited to transboundary output. European Union, Japan and other developed countries have developed and implemented the relevant laws, is to regulate and strengthen the CRT treatment and disposal management [6]. Some small countries such in Europe or some special regions such as Macau are due to the limitation of the “Basel Convention”, scrap CRT display must be treated in homeland. But the small countries and special regions have the impact of local economic, science and technology, they cannot have the effective resource utilization, but a lot of waste are generated and cannot be ignored, the only way of treatment is for a simple dismantling and classification. This article will take a research on the environmental impact assessment of scrap CRT display in the three scenarios of treatment which are the manual dismantling, mechanical dismantling and incineration .Dismantling the whole machine of scrap CRT display is divided into two forms, one is manual dismantling and the other is mechanical dismantling. Among them, the major application in domestic is the manually dismantling, European countries are using the machinery dismantling which does not produce toxic products. It is the unique advantage of it. Use life cycle

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assessment to assess the disposal of electronic waste. Take CRT display treatment as a case to carry out the analysis of life cycle assessment analysis. 2. Methodology LCA [7] is an evaluation system-related environmental load process of the product, process or activity from the collection and processing of raw materials to production, transportation, sales, utility, recovery, conservation, recycling and final disposal of the entire life cycle. Life cycle assessment was initial produced and firstly widely used in the corporate sector, some of the world's leading multinational companies such as HP [8], IBM [9,10], AT&T [11], Siemens [12], etc. On the one hand, they carried out research on life cycle assessment methodology; on the other hand, it is positive life cycle assessment of their products. Duan Huabo [13], carried on the whole life cycle assessment to personal desktop computer in China, e-waste currently has become a very important type of waste in world. Gao Lixia [14]ˈ researched on the life cycle assessment of the 100 computers, which accesses to raw materials, production, sales and transportation, using of the four stages. The result of the research showed that, the most serious of the environmental impact stage of the computer is in the using phase. Toxic and hazardous of component and precious metals resource characteristics, therefore, the life cycle analysis ofelectronic waste is very necessary. Maria Leet Socolof [15] comparied the CRT and LCD desktop computer displays of the environmental life cycle impacts for the entire life cycle, the results provide separate analyses for each impact category to allow manufacturers, or any user of the study results, to focus on particular areas of interest. The paper presented more detailed results of three impact categories (energy, global warming, and chronic public health toxicity) in addition to the overall comparative results. Michael S. Noona [16] researched about end-of-life computer monitor management in the seattle metropolitan region use life cycle assessment method, the result shows that LCD monitor disposal had lower impacts than CRT monitor disposal in all impact categories except for the management of mercury. This research only focuses on the scrap CRT display treatment in three scenarios in small countries and special regions. 2.1. Goal, scope and system boundary The goal of the LCA was to establish a scientific method that evaluates the life cycle environmental impacts of scrap CRT display in three scenarios according to the international standards of the ISO14040 series [17, 18, 19]. The aim of the paper here is to assess the scrap CRT display treatment technology. The environmental assessment of the dismantling and incineration are important to the human health, ecological quality and the resource. This examined scrap CRT display treatment system is taking into account the life cycle of the composition of the scrap CRT display. Hereby it only concludes the phase of the treatment of the CRT display, the aim of the research is not focusing on the entrie life cycle. The functional unit is a scrap CRT display treatment system, which consists of three different subunits. The scrap CRT display includes the whole display. The end-of life treatment phase is until to the treatment plant for manufacturing and incineration. The data are obtained from the environmental protection bureau environmental report. The data of the composition are the average data of the several types. 2.2. Life Cycle Inventory

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In this study, life cycle inventory data are from the literature, statistical analysis of data, theoretical and practical data protection manual. Taking into account the electricity used in the production of a larger role, while the electricity production process to form a larger pollution, this study will be used in electricity emissions into the system. Life cycle analysis of data sources are listed in Table 2. In the production and disposal processes, analysis of electricity using, natural gas and coal combustion emissions are shown in Table 3.The life cycle inventory analysis of the household solid waste incineration is listed in Table 4. Table 2. Life Cycle Analysis of Data Sources Item

Phase

Data Sources

CRT composition analysis

—

Literature

Power employ pollution emission

—

Environmental Protection Use data handbook

Coal combustion pollution emission

—

Environmental Protection Use data handbook

Natural gas combustion pollution emission

—

Environmental Protection Use data handbook

Household garbage incineration

Comprehensive utilization

Ecoinvent 2.0

Table3. Electricity Using, Natural Gas and Coal Emission Data

Pollutant

Electricity Use Emissions Intensity

Natural Gas Combustion Emissions Intensity

Coal Combustion Emissions Intensity

(kg/kwh)

(kg/104m3)

(t/t)

CO2

1.07

1.6×104

2.79

SO2

9.93×10ˉ3(

1.0

9.60×10ˉ3

NOx

6.46×10ˉ3

6.3˄NO2˅

9.08×10ˉ3˄NO2˅

CO

1.55×10ˉ3

2.72

1.36×10ˉ3

CH4

2.60×10ˉ3

0.48˄CH compound˅

4.50×10ˉ4˄CH compound˅

NMVOC

4.87×10ˉ4

ˉ

ˉ

Dust

2.02×10ˉ2

2.40

0.17

As

2.00×10ˉ6

ˉ

ˉ

Cd

1.27×10ˉ8

ˉ

ˉ

Cr

1.69×10ˉ7

ˉ

ˉ

Hg

8.78×10ˉ8

ˉ

ˉ

Ni

2.50×10ˉ7

ˉ

ˉ

Pb

1.76×10ˉ6

ˉ

ˉ

V

2.88×10ˉ6

ˉ

ˉ

Zn

2.40×10ˉ6

ˉ

ˉ

579

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Table 4. CRT Display Incineration of Life Cycle Inventory Analysis Phase

Input

CRTs Treatment

Output

Metal

0.835

CRT Dispaly Incineration

15.83˄kg˅

Electric Energy

0.18˄kwh˅

Plastic

1.91

Circuit Board

1.690

Electron gun controller

0.405

CRT Display Manual Dismantling

15.83˄kg˅

Cable

0.2

Electric Energy

0.00012˄kwh˅

Bulb

12.00

Other small parts

0.115

CRT Display Mechanical Dismantling

15.83˄kg˅

Feed quality

15.83

Electric Energy

0.15˄kwh˅

2.3. 2.3 Life Cycle Impact Assessment The life cycle impact assessment uses the Eco-indicator99 method. In the Eco-indicator99 method, the 11 categories on impact of pollutants of the environment category are: carcinogens, Respiratory organics, Respiratory in-organics, climate change, radiation, ozone layer, eco-toxicity, acidification / eutrophication, land use, minerals, fossil fuel. According to research data and conditions of data collection, the scrap CRT display treatment technology is namely: the incineration and dismantling of CRTs. Through the software analysis, result of life cycle assessment of household waste incineration is shown in Figure 1-5.

Incineration ManuallyDismantling

Carcinogens Respiratoryorganics RespiratoryinͲ… Climatechange Radiation Ozonelayer EcoͲtoxicity Acidification/Eutrop… LandUse Minerals Fossilfuels

3.50E+01 3.00E+01 2.50E+01 2.00E+01 1.50E+01 1.00E+01 5.00E+00 0.00E+00

Figure 1. Characterization of LCIA

MechanicallyDismantling

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2.50E+01 2.00E+01 1.50E+01 HumanHealth EcologicalQuality

1.00E+01

Resources 5.00E+00 0.00E+00 Incineration

Figure 2. Damage Evaluation of LCIA

Figure 3. Standardization of LCIA

Manually Dismantling

Mechanically Dismantling

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Figure 4. Weight of LCIA

Figure 5. Single Score of LCIA

3. Results The results of the research is showeds the scrap CRT display in the three scenarios of treatment technology which are incineration, manual dismantling and mechanical dismantling. The each assessment

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steps all indicates that the incineration treatment technology has the highest environmental impacts in the three scenarios. Because in the incineration phase, there are many toxic material are produced. In the dismantling of the two type, The mechanical dismantling consumes more electricity energy, so it has a high environmental inpactimpact in the resources. In addition to re-use technologies, recycling used CRT display is mainly based on the cleaning, dismantling technologies. Through the dismantling of scrap CRT display, it is can achieve the recycling and reuse of the materials of used CRT display. General steps are as follows: First, after dismantling the whole CRT display, by recycling the monitor casing, printed circuit boards, metal coils, etc., it can be gain the reusable metals and plastics. Because the metal is generally cemented together with plastic, metal recycling needs through a mixture of metal and plastic crushing, sorting and other pre-treatment process, then the content reaches a certain level and it is smelted to be metal. The plastic parts during washing, crushing, granulation and other processed wood materials can be made of it. Secondly, CRT tubes, using a reasonable method of dismantling, the full use of CRT glass components can get back, such as coneshaped glass, screen panels, etc., or can be get re-generated CRT glass raw materials. The complete recovery of CRT glass components in the polished, polishing and testing can be re-used after the production of CRT. The broken glass nibs, because of its special composition, the dedicated CRT glass can be used to reproduce, so that it both can be recycled resources, you also can prevent more harmful ingredients such as lead into the environment. Currently, the two recovery methods in the practice of foreign resources have been achieved in. As developed countries, especially Japan and the United States, the treatment processing technology of wasted CRT display is quite mature, added with the attention of government, so in addition to reuse the used CRT tube, the recovery of plastic, leaded glass and precious metals also has achieved industrialization. In China, the function is still remained of a used CRT display is treated through the clear washing, maintenance, testing and other steps after reuse. In addition, loss of function part of the used computer CRT display is used quite backward methods for processing, the main treatment is to control the neck with a hammer then recovery of the deflection coil of copper and the remained lead glass is freely discarded. The recovery is lack the necessary operating conditions and procedures, therefore, the entire recovery process cannot really reaches the comprehensive and rational recovery of recoverable resources, but also resulted in the pollution of the surrounding environment. 4. Conclusions and Suggestions Figure 1-5 show the life cycle assessment result of treating waste treatment process. The results shows that the environmental impact of incineration of CRT display has the greatest potential impact on the environment which is 2.62. The affect from inorganic pollution in the atmosphere through the entire chain is relatively large, leading impact on human health increase to 1.82; followed by resources, to 0.518, mainly due to fossil fuels are consumed in the process of the incineration. The incineration is the main contribution factor in the life cycle assessment of treatment on CRT. So in order to decrease the environmental impact in the process of incineration, reducing the amount of CRT for incineration is necessary. Then the CRT can be disposed for manual dismantling. This research is focused on the treatment phase of the used CRT display, the suggestion of the research can be extend to the whole life of the e-production from the collection of the raw material to the end of life phase. So the entire life cycle assessment can afford the more accurate data for reference. Acknowledgement

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This study was funded by the National High Technology Research and Development Program of China (863 program 2009AA06Z304), the project “The controlling of vehicle exhaust pollution and electronic waste and their recycling technology demonstration in Macauā (SQ2009AA06Z3483770) and by the University of Macau. References [1] Lin Song, Xu Hui. E-waste pollution Analysis and Contol.Environmental Protection and Circular Economy. 2009(10):35-37. [2] Li jinhui, Wen xuefeng.Electronic Waste Treatment Technology.࣫ Beijing, China Environmental Science Press.2006. [3] Wu Ting, Li Jinhui, Li Yonghong. Management and Technique for Resource Rrecovery of Waste CRT Monitors. Techniques and Equipment for Environmental Pollution Control.2003(11). [4] Zhang Youyu. Adverse Effects of Environmental Lead on Children’s Health. , SICHUAN ENVIRONMENT.1997(4). [5] Fu Aimin, Li Fengmin. Research On Reutilization Of Waste Computer Equipment. Environmental Science and Management.2006(4). [6] Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal. [7] Wang Yi, Wei Jiang, Xu Qingrui. Life-Cycle Assessment: Application, Connotation & Challenge. Environment Herald, 1998(5):27-29. [8] Duan Ning. Cleaner Production, Eco-industry and Circular Economy. Research of Environmental Sciences, 2001, 14(6)1-4, 8. [9] Brinkley, Anne, Kirby J. Ray, Wadehra, Inder L., Besnainou, Jacques, Coulon, Remi, and Goybet,Stephanie, Life cyele inventory of PVC: Disposal options for a PVC monitor housing, IEEEInternational Symposium on Eleetronies & the Environment, 1995: 145-151. [10] Brinkley, Anne, Kirby, J.Ray, Wadehra, Inder L., Besnainou, Jacques, Coulon, Remi, and Goybet, Stephanie, Life cyele inventory of PVC :manufacturing and fabrieation processes, IEEE Intemational Symposium on Electronies & the Environment, 1996: 94-101. [11] KeoleianˈGregory A., Glantsehnig, Werner, Life cycle design:AT&T demonstration Projeet, IEEE international SymPosium on Eleetronies& the Environment, 1994, P134-135. [12] Touchton, George L, Quentin, George H., and Mastrodonato, Bart, Lessons learned from durability surveillance of advanced gas tubines, American Society of Mechanical Engineers (Paper), 1997, 97-AA-123. [13] Duan Huabo, Martin Eugster. Life cycle assessment study of a Chinese desktop personal computer. Science of the Total Environmental, 407(2009), 1755-1764. [14] Gao Lixia. Life Cylce Assessment on Electronics and Information Products. Environmental Science and Management.2009(10). [15] Maria Leet Socolof , Jonathan G. Overly, Jack R. Geibig. Environmental life-cycle impacts of CRT and LCD desktop computer displays. Journal of Cleaner Production. 13 (2005) 1281-1294. [16] Michael S. Noona, Seung-Jin Leeb, Joyce S. Cooperb. A life cycle assessment of end-of-life computer monitor management in the Seattle metropolitan region. Resources, Conservation and Recycling 57 (2011) 22–29. [17] ISO (International Standard Organization). 14040 series:environmental management – life cycleassessment – principles and framework. ISO 14040 series. www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?%20csnumber=23152, Dec 2000. [18] Pennington DW, Potting J, Finnveden G, Lindeijer E, Jolliet O, Rydberg T, et al. Life cycle assessment Part 2: current impact assessment practice. Environ Int 2004, 30 (5): 721–39. [19] Rivela B, Moreira MT, Muñoz I, Rieradevall J, Feijoo G. Life cycle assessment of wood wastes: a case study of ephemeral architecture. Sci Total Environ 2006, 357 (1–3):1-11.