(42寸液晶電視價格)42寸液晶電視導購指南

1、Life Cycle Assessment: A Tool for Evaluating and Comparing Different Treatment Options for Plastic WastesG. Dodbiba 1, K.Takahashi 1, T. Furuyama 2,J. Sadaki 1, T. Kamo 3, and T. Fujita 11. Department of Geosystem Engineering, The University of Tokyo, Japan2. Department of Earth Resource Engineering

2、, Kyushu University, Japan3. National Institute of Advance Industrial Science and Technology, Japan 聚劃算 LCA Methodology (ISO 14040)2. LCA of Plastic Wastes from Discarded TV Sets3. Concluding Remarks.1. LCA Methodology (ISO 14040)2. LCA of Plastic Wastes from Discarded TV Sets3. Concluding RemarksOu

3、tline.Scope of LCA to evaluate or compare the life cycle of “products.Life-Cycle Stages and Boundaries(Source: EPA, 1993).Definition of products;Choice of alternatives;Definition of system boundary;Data collection; Theoretical calculation;EvaluationReporting the results;Propose improvement;Methodolo

4、gy: Life Cycle Assessment, (ISO 14040)Phase 1:Phase 2:Phase 3:Phase 4:(Source: Consoli et.al., 1993).Aim of Study to evaluate and compare different recycling options for plastic wastes from old TV sets in context of LCA .Compositions of a TV Set (weight %)(Source: O. Murakami, Mitsubishi Elec. ADVAN

5、CE, pp. 6-9, 2001). .Source: Association for Home Electrical Appliances of Japanaeha.or.jp/assessment/en/english_flame.html Conventional Recycling System for TV setsProblem: How to recycle plastic wastes?.Objective to compare two different recycling options for plastic wastes from old TV sets in con

6、text of LCA.Option 1: Incineration of plastics for energy recovery (also known as thermal recycling)Option 2: Sorting plastics for mechanical recycling (also know as material recycling).1. LCA Methodology (ISO 14040)2. LCA of Plastic Wastes from Discarded TV Sets3. Concluding RemarksOutline.Definiti

7、on of products;Choice of alternatives;Definition of system boundary;Phase 1:(Source: Consoli et.al., 1993)Methodology: Life Cycle Assessment, (ISO 14040).a. Subject of the study are plastic wastes from old TV sets (display: 25, weight = 30 kg), which contain:b. Functional unit: is defined as 1.8 mil

8、lion TV sets per year, over a period of 10 years.Phase 1 of LCA: Goal Definition and ScopePS (6.0 wt%, i.e. 1.80 kg),PVC (3.5 wt%, i.e. 1.05 kg), PE (1.0 wt%, i.e. 0.30 kg).Special cases: (1). Energy recovery, i.e. c = 0 %;(2). Mechanical recycling, i.e. c = 100 % and r = 67 %Life-cycle of plastics

9、for TV sets.Data collection; Theoretical calculation;Phase 2:(Source: Consoli et.al., 1993)Methodology: Life Cycle Assessment, (ISO 14040).The data of the processes, namely:were from the LCA database of the Japan Environmental Management Association for Industry (JEMAI). Phase 2 of LCA: Inventory an

10、alysisa) Data collectionproduction of PS,production of PVC,production of PE,production of electricity,production of a TV set, .Option 1: Incineration of 1 kg plastic materialEnergy generated:PS 9,604 kcal/kg PVC 4,300 kcal/kgPE 11,140 kcal/kgEmission:2,640 g CO2 /kgSource: K. Krekeler et al., Kunsts

11、offe, 55/10, pp. 758, 1965Phase 2 of LCA: Inventory analysisa) Data collectionSource: Ministry of Environment of Japan, Guidelines, 2004.PS1050PE960PlasticsDensity, kg/m3PVC 1400 1st Step2nd StepOption 2: Separation of plastic wastes prior to mechanical recycling.Option 2: Separation of plastic wast

12、es(by combining triboelectric separation and air tabling)Energy:0. 74 kWh/kgTriboelectric separator0.04 kWh/kgAir table0.66 kWh/kgSize reduction0.02 kWh/kgSieving0.02 kWh/kgRecovery of products: 67 % Grade of products: 95 %Phase 2 of LCA: Inventory analysisa) Data collection.Steps to be followed in

13、theoretical calculation:Calculate the inverse of matrix of A (i.e. A-1)Calculate the inventory vector gPhase 2 of LCA: Inventory analysisb) Theoretical calculationsthe matrix A represents the flow of products and materialsg is the vector of the environmental interventionsthe matrix B represents the

14、flow of environmental loadsthe vector f represents a special process where the functional unit is an output .EvaluationPhase 3:(Source: Consoli et.al., 1993)Methodology: Life Cycle Assessment, (ISO 14040).The categories of the environmental impacts:a) Abiotic resources:ADP (in kg Sb eq.)b) Global wa

15、rming:GWP (in kg CO2 eq.)Phase 3 of LCA: Impact assessment.Phase 3 of LCA: Impact assessment a) Depletion of Abiotic Resources, (ADP).Phase 3 of LCA: Impact assessment a) Depletion of Abiotic Resources, (ADP)1.6 x.Phase 3 of LCA: Impact assessment b) Global Warming Potential (GWP).Phase 3 of LCA: Im

16、pact assessment b) Global Warming Potential (GWP)1.4 x.Reporting the results;Propose improvement;Phase 4:(Source: Consoli et.al., 1993)Methodology: Life Cycle Assessment, (ISO 14040).Phase 4 of LCA: Main ResultsEnvironmental Impact1.5 x.Outline1. LCA Methodology (ISO 14040)2. LCA of Plastic Wastes f

17、rom Discarded TV Sets3. Concluding Remarks.Concluding RemarksThe energy recovery (option 1) and the mechanical recycling (option 2) of plastic wastes from the discarded TV sets were compared in the context of LCA. The energy recovery is an treatment option that generated more energy due to the incin

18、eration of plastic wastes. Nevertheless, this option also uses more resources and emits a larger quantity of greenhouse gases. The separation of plastics for mechanical recycling is more effective alternative, because it consumes fewer energy and resources, as well as has a lower environmental impac

19、t on global warming.Source: Matsushita Eco Technology Center (METEC)Available from internet: panasonic.co.jp/eco/en/metec/tv/material2-1.htmlConventional Recycling System for TV sets. Three alternatives are being considered when dealing with plastic wastes: energy recovery (also known as thermal rec

20、ycling), i.e. direct incineration of plastic wastes for energy recoverymechanical recycling (also known as material recycling), i.e. the method by which plastic wastes are recycled into new resources without affecting the basic structure of the material; feedstock recycling (also known as chemical r

21、ecycling), i.e. the technique that break down polymers into their constituent monomers, which in turn can be used again in refineries or petrochemical and chemical production.Required Purity of Sorted Plastics for Reuse (courtesy of KINKI KOGYO Co. Ltd., Japan) Reuse of plastics in circulating syste

22、m as low grade plastics : 95.0 % Reuse of plastics in circulating system as virgin plastics : 99.5 % Reuse of plastics for agricultural, horticultural industry, etc. : 99.0 % Use of plastics as oxidant in blast furnaces : 1.0 % (PVC impurity) .Life Cycle Assessment Framework(Source: LCA, ISO 14040).

23、Bonds Method: Size-reductionWi = 13.81 kWh/tDP = 2.63 mmDF = 5.00 mm.Production of 1 kg PS(Source: JEMAI-LCA On-line Database).Production of 1 kg PVC(Source: JEMAI-LCA On-line Database).Production of 1 kg PE(Source: JEMAI-LCA On-line Database).Production of 1 kWh Electricity(Source: JEMAI-LCA On-lin

24、e Database).Production of a TV set(Sources: a. JEMAI-LCA On-line Database; b. Murakami, 2001).Matrix B of Environmental interventions .Demand vector, f.Technological Matrix, A.Structure of LCA model.INPUT (product flow) x (scaling parameter) = (final demand)After choosing the FINAL DEMAND of the pro

25、duct, the simplest UNIT PROCESS can be written as follows:OUTPUT(environmental flow) x (scaling parameter) = (environmental intervention)Ref.: Leontief, 1970 (Winner of Nobel Prize in 1973).Technology matrix;AFinal demand vector;fEnvironmental intervention matrix;BInventory;g?ProcessInput ( - )Outpu

26、t ( + )Inventory dataProcess 1 Process nTechnological parametersEmission from the process.Linear programmingProduct flow, aScaling parameter, sDemand, fEnvironmental flow , bEnvironmental intervention , g(Heijung et.al, 2002).Equations can be written in terms of matrixes.Technology matrixFinal deman

27、d vectorScaling vectorIntervention matrixInventory vector.Inverse matrix of technology matrix AFinal demand vectorScaling vectorEnvironmental intervention matrixInventory vectorSolution:Linear programming / Matrix manipulation(Heijung et.al, 2002).The outcome of the inventory analysis was the vector

28、 g, which is a list of the quantities gi of pollutants released to the environment and the amount of energy and materials consumed during the life-cycle of plastics for TVs production (Matrix B), i.e.:for i = 1, 2, , nLCI Results g vector.The categories of the environmental problems:Resource depleti

29、on/Abiotic depletion ADP (in kg Sb eq.)Global warming GWP (in kg CO2 eq.)Acidification, AP (in kg SO2 eq./kg)Photo-oxidant formation, POCP (in kg C2H4 eq./kg)Eutrophication, EP (in kg PO4 eq./kg)Human toxicity, HTP (in kg 1,4-DCB eq./kg) Phase 3 of LCA: Impact assessment.How to calculate the environ

30、mental impact?The impact indicator Ij of each category was calculated after all the environmental loads gi within a category were characterized and aggregated using the following equations, Results of LCI, g vector.Characterization factors, kiSource: Handbook of LCA, 2002.Normalization q indicates t

31、he number of the environmental impact categories.The indicator Ij of each environmental impact category is divided by a reference value known as normalization factor wj .World (1995)ADP1.57 1011kg (Sb eq.) yr-1GWP3.86 1013kg (CO2 eq.) yr-1AP2.99 1011kg (SO2 eq.) yr-1POCP4.55 1010kg (C2H4 eq.) yr-1EP1.29 1011kg (PO4 eq.) yr-1HTP4.98 1013kg (1,4-DCB eq.)