Life Cycle Modeling. Modeling Architecture, Engineering & Mike Lepech, PhD, MBA Stanford Civil & Environmental Engineering

Transcription

1 Life Cycle Modeling CEE 214 Modeling Architecture, Engineering & Construction Projects Mike Lepech, PhD, MBA Stanford Civil & Environmental Engineering October 12,

2 Outline Industrial Ecology Life Cycle Assessment Sustainability Modeling, ISO, and Process-based LCA LCA Results Case Studies Consumer Products Weighting and Valuation Lab Tasks 2

3 Industrial Ecology systematically examines local, regional, and global uses and flows of materials, and energy in products, processes, industrial sectors and economies Journal of Industrial Ecology the study of the flows of materials and energy in industrial and consumer activities, of the effects of these flows on the environment, and of the influences of economic, political, regulatory, and social factors of the flow, use and transformation of resources. Robert White, President of the US Academy of Engineering 3

4 Nature as a model The industrial ecosystem would function as an analogue of biological ecosystems. (Plants synthesize nutrients that feed herbivores, which in turn feed a chain of carnivores whose wastes and bodies eventually feed further generations of plants.) Frosch and Gallopoulous,

5 Ecosystem Analogy Natural ecosystems cyclical flows highly integrated utilize solar energy declining Industrial ecosystems linear flows less integrated exploit fossil fuels expanding 5

6 Type I System Unlimited Resources Organism Unlimited (Ecosystem Sinks for Component) Wastes 6

7 U.S. Arsenic Use 7

8 CCA treated wood Florida accounts of 15% of CCA (chromated copper arsenate) treated wood used in the US Arsenic concrntration is 600 micrograms/liter in rainwater runoff from a CCA-treated deck (100X higher than untreated). Layer of sand under deck captures As (30 mg/kg) x background. By 2000 FL imported 28,000 metric tons As 4600 of which have already leached into the environment Estimate that 40% will leach over service life (9 13 yrs for products such as decks) 8

9 Type II System Energy & Limited Resources Ecosystem Component Limited Wastes Ecosystem Component Ecosystem Component 9

10 U.S. Lead Flows ( ) 10

11 Type III System Energy & Limited Resources Ecosystem Component Ecosystem Component Ecosystem Component 11

12 Biomimicry Nature as model study nature s models and imitate it t designs and processes to solve human problems Nature as measure ecological standard to judge our innovations Nature as mentor new way of viewing and valuing nature (era based on we what we can learn not what we can extract from nature) Janine Benyus Biomimicry: Innovation Inspired by Nature 12

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14 Eco-industrial park a community of manufacturing and service businesses seeking enhanced environmental and economic performance through collaboration in managing environmental and resource issues including energy, water, and materials. Industrial symbiosis mutually beneficial exchange of material and energy between individual firms located in close proximity symbiosis = biological term referring to a close sustained living together of two species 14

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18 Building a Model for Quantitatively Assessing Sustainability 18

19 Outline Industrial Ecology Life Cycle Assessment Sustainability Modeling, ISO, and Process-based LCA LCA Results Case Studies Consumer Products Weighting and Valuation Lab Tasks 19

20 Maria Modeling Steps 1. Identify the Problem 2. Formulate the problem a. Define the overall objective b. State performance measures c. Decide time frame d. Develop initial schema models e. Describe the reasoning to transform input into output 3. Collect and Process Real System Data 4. Validate the Model 5. Interpret t and Present Results 6. Recommend Further Action 20

21 Defining Sustainability 1. Identify the Problem 2. Formulate the problem a. Define the overall objective b. State performance measures c. Decide time frame d. Develop initial schema models e. Describe the reasoning 3. Collect and Process Real System Data 4. Validate the Model 5. Interpret and Present Results 6. Recommend Further Action Populations Human Needs Production & Consumption Activities Material & Energy Flows Changes in Ecosystem States set of integrated human-designed and ecological processes for meeting human needs while maintaining the long term integrity it of the planet s life support system - UM Center for Sustainable Systems (1999) 21

22 Sustainability Indicators 1. Identify the Problem 2. Formulate the problem a. Define the overall objective b. State performance measures c. Decide time frame d. Develop initial schema models e. Describe the reasoning 3. Collect and Process Real System Data 4. Validate the Model 5. Interpret and Present Results 6. Recommend Further Action Social Demographic Indicators Economic Indicators Ecological Indicators Human Needs Consumption and Production Activities Material and Energy Flows Ecosystem State Sustenance Clothing Shelter Health Knowledge Mobility Communication Recreation/Leisure Manufacturing Construction Agriculture Services Education Utilities Infrastructure Recreation Materials Resource Use Energy Resource Use Waste/Emissions Atmosphere Lithosphere Hydrosphere Biosphere 22

23 Production/Consumption Processes and Material/Energy Flows Primary Materials (e.g., ores, biotic resources) Recycled Materials (open loop recycling) Primary Energy (e.g., coal) Capital ($) Labor (e.g., human labor, biological labor) Raw Material Acquisition Material Processing recycling Retirement & Recovery Disposal remanufacture Manufacture &A Assembly Use Service reuse Air pollutants (e.g., Hg) Water pollutants (e.g., BOD) Solid waste (e.g., MSW) Products (e.g., goods, services) Co-products (e.g., recyclables, energy) Processes and flows are spatially and temporally distributed 23

24 LCA Standards ISO: International Organization for Standardization LCA standards are voluntary Part of Environmental Management Series LCA Standards: Principles and Framework Goal and Scope Definition and Inventory Analysis Impact Assessment Interpretation series: Environmental Labeling 24

25 LCA Requirements (ISO:14040) Goal and scope definition Inventory analysis Interpretation Impact assessment 25

26 Goal of the study Goal and Scope State the intended application Identify the intended audience Scope of the study 1. Identify the Problem 2. Formulate the problem a. Define the overall objective b. State performance measures c. Decide time frame d. Develop initial schema models e. Describe the reasoning 3. Collect and Process Real System Data 4. Validate the Model 5. Interpret and Present Results 6. Recommend Further Action Function and functional unit System boundaries Data requirements/assumptions/limitations Critical review and report format 26

27 Functional Unit Function Service provided by system; performance characteristics of the product Functional unit Means for quantifying the product function Basis for an LCA Reference for normalization of input and output t data 27

28 Function and Functional Unit Study objective is to compare paper towel and an air-dryer system for drying hands Function: drying hands Functional Unit: number of pairs of hands dried by both systems

29 Functional Unit Product System Function Functional Unit PV plant Supply electricity 1MW of electricity Light bulb Pipe Beverage container Illuminate a defined ed space for a certain time period Provide a conduit for potable water, ID ½ inch for a certain time period To deliver beverage to the consumer 1500 lumens for 10,000 hrs Carry water for 200 ft over a 50 yr period 100,000 liters of beverage delivered to the customer

30 Primary Materials (e.g., ores, biotic resources) Process-based LCA Raw Material Acquisition 1. Identify the Problem 2. Formulate the problem a. Define the overall objective b. State performance measures c. Decide time frame d. Develop initial schema models e. Describe the reasoning 3. Collect and Process Real System Data 4. Validate the Model 5. Interpret and Present Results 6. Recommend Further Action Air pollutants t (e.g., Hg) Recycled Materials (open loop recycling) Material Processing Manufacture &A Assembly Water pollutants (e.g., BOD) Primary Energy (e.g., coal) Capital ($) Labor (e.g., human labor, biological labor) recycling Retirement & Recovery Disposal remanufacture Use Service reuse Solid waste (e.g., MSW) Products (e.g., goods, services) Co-products (e.g., recyclables, energy) Processes and flows are spatially and temporally distributed 30

31 System Analysis Process Flow Diagram Product System for a Plastic Cup

32 Process Flow Diagram Fuel Tank

33 Process Flow Water Tank

34 Process Flow Water Tank Concrete Tank FRP Tank Raw materials (e.g. limestone, cement rock, waste oil, gypsum) Aggregate / sand Cement Concrete Raw materials (e.g. pig iron, oxygen, alloy metals) Water Gel coat Steel Rebar Plywood Timber Formwor k Releas e agent Steel scrap Material Production Electricity Sand Feldspar Sodium Sulfate Borax Boric Acid Fuel Process Energy Process Mat ls (Epoxy) Glass Materials Handling, Transport, Melting, and Refining Glass Fiber Compression, Curing, Cooling, and Fabrication Resin Production Electricity Oil Fuel Recycled aggregate Electricity Sand Feldspar Sodium Sulfate Borax Boric Acid Fuel Process Energy Process Mat ls (Epoxy) Equipment (e.g. excavator, concrete mixer, pumps, etc) Equipment Equipment Tank Construction Tank Glass Materials Maintenance Handling, Transport, Melting, and Refining End of Life Landfill Glass Fiber Compression, Curing, Cooling, and Fabrication Labor (e.g. engineering, construction, inspection) Labor Labor Reused forms Raw materials (e.g. limestone, cement rock, waste oil, gypsum) Aggregate / sand Resin Production Construction Fabrication Use Cement Water Electricity i End of Life Raw materials (e.g. pig iron, oxygen, oyge,aoy alloy metals) Labor Equipment Equipment Steel Oil Fuel Concrete Gel coat Rebar Laying of FRP Tank Assembly Tank Maintenance Plywood End of Life Landfill Scrap/Waste Timber Labor (e.g. engineering, inspection) Labor Labor Formwor k Releas e agent Steel scrap

35 Initial System Boundaries Determine which h unit processes should be included. Example Compare wall board formulations what components of the system might be excluded?

36 Data Categories Inputs Energy (renewable/non-renewable) renewable) Materials (renewable/non-renewable) Labor Outputs Products (electricity, materials, goods, services) Waste (hazardous, non-hazardous) Emissions (air and water pollutants) Co-productsp

37 Criteria for initial inclusion Mass Energy Environmental relevance Toxicology Health Impacts Bioaccumulation

38 CEE 226 Autumn Material Production Modeling: Renewable Feedstocks 38

39 Lifecycle Inventory (LCI) 1. Identify the Problem 2. Formulate the problem a. Define the overall objective b. State performance measures c. Decide time frame d. Develop initial schema models e. Describe the reasoning 3. Collect and Process Real System Data 4. Validate the Model 5. Interpret and Present Results 6. Recommend Further Action The identification and quantification of relevant inputs and outputs for a given system throughout its life cycle Franklin and Associates EcoInvent BEES APME NREL ELCD Others 39

40 US Electricity Life Cycle Inventory Kim. S. and Dale, B. (2005) 40

41 APME LCI Database to page 4 Brine extraction - Brine purification - chlorine electrolytic hydrogen hydrogen chloride pentane toluene p-xylene p-xylene benzene cracker hydrogen cyclohexane Hydrogenation propylene ethylene butadiene acetic acid Acetic acid production - methanol natural gas carbon monoxide reformer hydrogen ammonia ammonia brine Brine electrolysis - NaOH Cl 2 H 2 toluene p-xylene separation - benzene - pipeline pp ethylene methanol Methanol production - CO H 2 Ammonia production - syngas HCl production - Crude oil extraction - HCl pentane xylenes Catalytic reforming - pygas H 2 pipeline propylene propylene ethylene butadiene Dehydrogenation - butenes Steam reforming - Natural gas extraction - crude oil Oil refining - naphtha Cracking - natural gas Natural gas processing

42 APME LCI Database from page 3 to page 5 thylene et natu ural gas prop pylene be enzene am mmonia Oxidation - Acrylonitrile production - HCN production - Cumene production - nitric acid Nitrobenzene production - acrylonitrile HCN cumene hyd drogen aniline Aniline production - acetone cyanohydrin Acetone cyanohydrin production - Catalytic rearrangement - trile acrylonit acetone cyanohydrin aceto one acetone phe enol phenol styre ene propylene oxide ethylene glycol ethylene oxide Ethylene oxide production - ethylene oxide ethylene Polymerisation for LDPE - LDPE resin propylene Propylene polymerisation - PP resin Ethylene glycol production - Oriented film HDPE pipe Pipe extrusion - ethylene glycol Blow moulding - LDPE bottles Film extrusion - extrusion - OPP film Injection moulding - Ethylbenzene production - ethylbenzene Propylene oxide production - Styrene production - propylene oxide styrene HDPE bottles Blow moulding - HDPE resin LDPE film Polymerisation for HDPE - PP mouldings Polymerisation for LLDPE - LLDPE resin 42

43 LC Impact Assessment 1. Identify the Problem 2. Formulate the problem a. Define the overall objective b. State performance measures c. Decide time frame d. Develop initial schema models e. Describe the reasoning 3. Collect and Process Real System Data 4. Validate the Model 5. Interpret and Present Results 6. Recommend Further Action Evaluation of the magnitude and significance of the potential environmental impacts of a product system using inventory analysis results 43

44 Characterization methods Loading assessment a less is better approach sums inventory inputs and outputs on a mass or energy basis into impact categories Equivalency assessment applies equivalency factors to inventory data and aggregates results e.g., GWP, ODP, AP CEE 226 Autumn Life Cycle Impact Assessment 44

45 Characterization methods Toxicity, persistence and bioaccumulation assessment inventory data are aggregated by considering chemical properties Generic exposure/effects assessment simplified models addressing persistence and fate in idealized environmental compartments to assess loadings Site-specific exposure/effects assessment site specific field studies and predictive models quantify fate and impacts CEE 226 Autumn Life Cycle Impact Assessment 45

46 PRé Consultants CEE 226 Autumn Life Cycle Impact Assessment 46

47 CEE 226 Autumn Life Cycle Impact Assessment 47

48 Global Warming Potentials Greenhouse gases GWP Carbon dioxide (CO2) 1 Methane (CH4) 23 Nitrous Oxide (N2O) 296 Hydrofluorocarbons (e.g., HFC 134a) 1300 Perfluorcarbon (e.g., CF4) 5700 Sulfur Hexafluoride (SF6) 22, IPCC 2007 CEE 226 Autumn Life Cycle Impact Assessment

49 Life Cycle Impact Categories Input related categories abiotic resource extraction biotic resource extraction land use Output related categories global change (climate, ecosystem, etc.) stratospheric t ozone depletion human toxicity ecotoxicity photo-oxidant formation acidification nutrification 49

50 Life Cycle Interpretation 1. Identify the Problem 2. Formulate the problem a. Define the overall objective b. State performance measures c. Decide time frame d. Develop initial schema models e. Describe the reasoning 3. Collect and Process Real System Data 4. Validate the Model 5. Interpret and Present Results 6. Recommend Further Action Draw conclusions and recommendations from inventory analysis and/or impact assessment weighting among various indicators identify major burdens and impacts select among alternative designs or materials Peer Review Internal Review External Review 50

51 Outline Industrial Ecology Life Cycle Assessment Sustainability Modeling, ISO, and Process-based LCA LCA Results Case Studies Consumer Products Weighting and Valuation Lab Tasks 51

52 Case Study Office Furniture Spitzley, D., B. Deitz, G.A. Keoleian (2006) Life Cycle Assessment of Office Furniture Products Center for Sustainable Systems, University of Michigan (CSS06-11) Adjustable Table Wood Casegood Executive Chair 52

53 LCA on Adjustable Table Functional Unit: 30 years of flat work space adjustable from 26 to 43 in height while supporting up to 25 lbs. Reference Flow: One 30x42 straight Adjstable height adjustable work surface (116 lbs) Materials and Energy Raw Material Acquisition T T T T T Part Forming Product Assembly Use & Service Retirement & Recovery Final Disposal Waste (solid, emissions, i effluent, etc.) Output t 53

54 Product Life Cycle Particleboard Production Extruded Aluminum Production Section Steel Production Cold Rolled Steel Coil Production Stainless Steel Production Steel Forming Processes Transportation Work Surface Production Column Assembly Base Assembly Transportation Product Consolidation Transportation Use Transportation End of Life Management Other Material Production Transportation Data from average databases Data from Manufacturer operations Data on average national processes Spitzley et al (2006)54

55 Product Composition Total product weight = 116 lbs Material modeling Work Surface = 37.2 lbs accounted for 99% 89% Particleboard of total product 8% Laminate mass 2% PVC 1% Adhesive Column = 45.2 lbs 56% Wrought Aluminum (inc. extruded and rolled) 27% Sheet Steel 13% Other Steels (inc. stainless) 3% Cast Aluminum 1% Polymers Base = 33.1 lbs 71% Section Steel 27% Sheet Steel 2% Cast Aluminum Spitzley et al (2006)55

56 Manufacturer Operations Example data: Manufacturing equipment data MIG welder (720 inch/hr) kwh/hr 684 cf comp. air/hr 360 gal water/hr Pneumatic screwdriver (data from Stanley Assembly Tech.) 1463 cf comp. air/hr Steel machining (average US data) 98 kwh/hr 8.9 kg scrap/hr Base assembly (approx. data) 24 MIG weld (2 min) Drill/Tap (5 min) Pneumatic Screwdriver (1 min) Overhead is not included in manufacturing data Spitzley et al (2006)56

57 End of Life US average durable goods (a) waste handling (US EPA, 2003) Material Recovery Rate (%) Ferrous Metals 28% Copper 60% Magnesium 60% Zinc 60% Aluminum 0% Glass 0% Polymers 5.5% (a) Durable goods include large and small appliances, furniture and furnishings, carpets and rugs, rubber tires, automotive batteries, and consumer electronics among other items. 57

58 Detailed Process Flow Transportation ti Subassemblies End of Life Process Energy Final Product OEM Processes Full life cycle model is comprehensive and detailed 203 nodes visible of 1715 Spitzley et al (2006)58

59 Life Cycle Analysis Results Spitzley et al (2006)59

60 Life Cycle Analysis Results Absolute Results ERC (MJ) ERC (MJ) 1.0 Intensity Results (per kg) ERC (MJ) ERC (MJ) 1.0 TMC (kg) GWP (kg CO 2 equiv) TMC (kg) GWP (kg CO 2 equiv) TMC(kg) GWP (kg CO2 eqv.) TMC(kg) GWP(kg CO2 eqv.) SW (kg) SW (kg) AP (H + AP (H+ mol eqv.) mol equiv) SW (kg) SW (kg) AP AP (H+ (H + mol eqv.) mol equiv) CP PM2.5 eqv.) CP (kg 2.5 equiv) CP PM2.5 eqv.) CP (kg 2.5 equiv) Spitzley et al (2006)60

61 Adjustable Table Energy Flows Base Column Surface Over 60% of life cycle energy consumed in aluminum extrusion process Baseline extruded aluminum uses 11% recycled content Increase of recycled content t to maximum of 22% yields 6% reduction in ERC Spitzley et al (2006)61

62 Adjustable Table CP Flow Over 68% of CP emitted in aluminum extrusion process Baseline extruded aluminum uses 11% recycled content Increase of recycled content to maximum of 22% yields 7% reduction in CP emissions Spitzley et al (2006)62

63 Wood Casegood Energy Flow Manufacturing of Particle Board Resin accounts for large portion of energy flow Mass contribution of ureaformaldehyde resin reduced from 9.5% to 4.9%. Reduction of ERC by over 10% Spitzley et al (2006)63

64 Outline Industrial Ecology Life Cycle Assessment Sustainability Modeling, ISO, and Process-based LCA LCA Results Case Studies Consumer Products Weighting and Valuation Lab Tasks 64

65 Valuation Techniques Highly Uncertain Policy Question Value Judgement Distance-to-Target to Environmental Control Costs Economic Damage Approaches Scoring Techniques 65

66 Distance to Target Derived from extent to which actual environmental performance deviates from some goal or standard. Ambient concentration of CO is 1.11 mg CO/m 3 Standard is 1.0 mg CO/m 3 Weight attached to standard d is 10% 66

67 Distance to Target - Downsides Standard is based on political achievability rather than scientific desirability. Politically determined standards are often arbitrary (Hird, 1994) Little transparency in targets (Lindeijer, 1996) Targets may relate to different time frames or geographies. Only emissions that have regulatory standards can be included. All targets are assumed to be equally important (Lindfors et al, 1995) Is this even weighting? 67

68 Environmental Control Costs Weights are derived from the expenditure necessary to control environmental damage. $2 to control pollutant A $1 to control pollutant B A has a weight twice that t of B Society has expressed a willingness to pay for achieving i a standard. d 68

69 Environ. Control Costs - Downside Control Costs = Damage Costs Revealed through the standard setting procedure If control costs = damage costs, then why any standard? Standard d emerges because damage costs > control costs! At best, control costs = min(damage costs) 69

70 Environmental Damage Costs Derived from Willingness to Pay (WTP) to avoid impacts identified in LCA. Economic values available for air pollution, casualties from road traffic accidents, road congestion. One unit ($) Acceptability of individual preferences as a policy guide Imperfect information (Pearce, 1994) 70

71 PRé Consultants CEE 226 Autumn Life Cycle Impact Assessment 71

72 Valuing the Ecosystem Value of Ecosystem Services = $33 trillion range: $16 - $54 trillion 1.8 x Global GNP 72

73 Estimation of Damage Costs - 1 Contingent Valuation public directly asked willingness to pay to gain or avoid some change in provision of a good or service Travel Cost Natural resources are used for recreation. Value of resource is equal to the cost of traveling to and from the site in terms of time and money Hedonic Pricing Changes in price of associated goods that do have markets. Price difference in two properties, one with good air quality, one with poor air quality. 73

74 Estimation of Damage Costs - 2 Replacement Cost cost of replacing or restoring a damaged asset to original state (cost of natural restoration in money or time) Dose-response Uses market prices to value some environmental impact. Used when there is a known relationship between some damage, such as pollution, and output/impact is known. (PM 10 leads to higher asthma, leading to days away from work, leading to lower productivity.) 74

75 Emissions Damage Cost Criteria Air Pollutants 2003 Urban ($/tpollutant) Urban fringe ($/tpollutant) Rural ($/tpollutant) dollars low mean high low mean high low mean high PM $5,037 $6,144 $7,251 $2,243 $2,750 $3,258 $635 $800 $965 NOx $99 $156 $212 $38 $65 $91 $8 $19 $29 SO2 $127 $170 $213 $51 $88 $125 $11 $20 $29 CO $1.20 $1.88 $2.56 $0.86 $ $1.51 $0.24 $0.35 $0.47 Pb $3,534 $3,955 $4,375 $1,865 $2,059 $2,253 $454 $480 $505 All regions ($/tpollutant) VOC $196 $1,960 $5,389 Greenhouse Gases Greenhouse Gas $/t Pollutant CO2 $21 N20 $7,112 CH4 $384 * All costs were converted to 2003 dollars, so they are higher than the values in the literature which ranged from dollars (Sources: Banzhaf, Tol and Matthews)

76 Discount Rate Selection Agency Discount Rate 4% (OMB) Social Discount Rates User costs 4% Environmental costs uses Weitzman s sliding discount rate Time Period Range in Years Discount Rate Immediate Future 1-5 4% Near Future % Medium Future %

77 Scoring Approaches Weights from group of experts or stakeholders Rank impacts in order Rank relative to other pollutants and impacts Delphi Technique (decision theory) Practicality varies with completeness Scientific vs. Socially Aware experts? Eco-indicator 77

78 Evaluation of Weighting Methods 78

79 Outline Industrial Ecology Life Cycle Assessment Sustainability Modeling, ISO, and Process-based LCA LCA Results Case Studies Consumer Products Weighting and Valuation Lab Tasks 79

80 Next Time for Lab Constructing Simplified Process Flow Diagram of System (POP model) Quantifying inputs and flows (quantity takeoffs) Constructing an Assembly (product) using Processes in SimaPro software Determining Environmental Impacts using SimaPro software 80

81 CEE 226 LCA for Complex Systems Autumn Quarter 81

82 Questions? Michael D. Lepech Stanford University stanford.edu/~mlepech 82