Presentation on theme: "Life Cycle Assessment: Laying the Foundation for a Transparent Supply Chain Shopping Bag Case Study September 26, 2013 Dr. Anahita Williamson Director."— Presentation transcript:
Life Cycle Assessment: Laying the Foundation for a Transparent Supply Chain Shopping Bag Case Study September 26, 2013 Dr. Anahita Williamson Director Kate Winnebeck LCACP, Senior EHS Specialist New York State Pollution Prevention Institute at RIT
Life Cycle Assessment (LCA) is a technique used to quantify the environmental impact of a product from raw material acquisition through end of life disposition (cradle-to-grave) Life Cycle Assessment Remanufacture Recycle Reuse Material Extraction Processing Component Fabrication Product Assembly Packaging & Distribution Use End of Use Processing Waste Treatment
LCA Methodology A Life Cycle Assessment is carried out in four distinct phases: (ISO 14040, 14044) –Step 1: Goal definition and scoping. Identify the LCA's purpose, the products of the study, and determine the boundaries. (what is and is not included in the study) –Step 2: Life-cycle inventory. Quantify the energy and raw material inputs and environmental releases associated with each life cycle phase. –Step 3: Impact analysis. Assess the impacts on human health and the environment. –Step 4: Report results. Evaluate opportunities to reduce energy, material inputs, or environmental impacts at each stage of the product life-cycle.
Step 1: Goal Definition and Scoping Define the goal: –Intended application of the study –Intended audience Define the scope: –Identify the product system to be studied –Define the functional unit –Define the boundaries of the product system –Identify assumptions and limitations of the study –Select impact categories to be included
Today’s Example You own a grocery store and customers are starting to request that you sell reusable shopping bags. You are curious which type of bag has the lowest environmental impact. In order to quantify and compare the bag options, a streamlined LCA is performed. Goal: –Determine which grocery bag – single use paper, single use plastic, reusable plastic, or reusable cotton – has the lowest environmental impact Sustainability Victoria, Comparison of existing life cycle analysis of shopping bag alternatives, Apr07.
Draw the System Boundaries Assumptions: –All bags are manufactured 100km from the customer –All bags travel 10km from the customer to the end of life –Half of paper bags are recycled at end of life, half go to landfill –Plastic & cotton bags go to landfill at end of life 1.As a group, draw the boundaries or process flow of the system
System Boundaries 50/50 to Landfill & Recycling Material Extraction Processing Bag Manufacture Packaging & Distribution UseEnd of Life Cutting down trees Paper bag Transform trees into paper Form paper into bags Packaging & Distribution Use Extracting petroleum Single use & reusable plastic bag Transform petroleum into plastic Form plastic into bags Packaging & Distribution UseLandfill
Functional Unit The functional unit is a measure of the function of the studied system –Provides a reference to which the inputs and outputs can be related –Enables comparison of two essentially different systems Examples –The functional unit for a paint system may be defined as the unit surface protected for 10 years –The functional unit for a printer may be defined as the number of printed pages of an acceptable print quality –The functional unit for power generation systems may be defined as 1kWh of electricity
The amount of shopping bags consumed by a household to carry 70 grocery items home from the supermarket each week for 52 weeks Bag Type Single use plastic Single use paper Reusable plastic Reusable cotton MaterialHDPE Unbleached Kraft paper PolypropyleneCotton Mass per bag7g42.6g95g85g Relative Capacity Bags per Year Mass bags per year 3640g g432.25g386.75g Functional Unit
Step 2: Life Cycle Inventory Highly data intensive Detailed mass & energy balances performed over life-cycle Advantages: measure data & define baseline metrics of life-cycle processes Challenges: Assumptions made when data unavailable
Outputs Products Air, Water and Solid Emissions Inputs Energy Raw Materials End of use processing Customer use Distribution Manufacturing Materials database Inventory collected from multiple sources Step 2: Life Cycle Inventory
Impact Assessment Results Impact assessment converts the inventory into impact categories or end points which details the human health and environmental effects.
High Density Polyethylene Inventory Peer reviewed datasets imbedded in software Data has been collected by others and represents actual operations Include: Known inputs Emissions to air Emissions to water Emissions to soil Wastes and emissions sent to treatment Ability to modify datasets based on your own data 2. As a group, choose one of the four bags and list the processes that are included in the inventory
Life Cycle Inventory Reusable Plastic Bag Polypropylene, granulate432.25g Extrusion, plastic film432.25g Transport, 100km manufacturing to customer tkm Transport, municipal waste collection, 10km customer to landfill tkm Disposal, polypropylene, to sanitary landfill432.25g Reusable Cotton Bag Textile, woven cotton, at plant386.75g Transport, 100km manufacturing to customer tkm Transport, municipal waste collection, 10km customer to landfill tkm Disposal, inert material, to sanitary landfill386.75g Single Use Plastic Bag Polyethylene, HDPE, granulate3640g Stretch blow moulding3640g Transport, 100km manufacturing to customer0.364tkm Transport, municipal waste collection, 10km customer to landfill0.0364tkm Disposal, polyethylene, 0.4% water, to sanitary landfill3640g Single Use Paper Bag Kraft paper, unbleached, at plant g Production of paper bags g Transport, 100km manufacturing to customer2.4623tkm Transport, municipal waste collection, 10km customer to landfill/recycling tkm Disposal, packaging paper, to sanitary landfill12311g Recycling paper12311g
Step 3: Impact Assessment Converts the inventory into impact categories or mid/end points which explain the environmental effect Impact categories may include: carcinogens, respiratory organics and inorganics, climate change, radiation, ozone layer, ecotoxicity, acidification/eutrophication, land use, minerals, fossil fuels Can apply weights to impact categories
Life Cycle Inventory NOx SOx Pesticides Heavy metals CO2 VOCs Particulates Chemicals Impact Categories Concentration in air, water, food Concentration greenhouse gases Changed pH and nutrient availability Change in habitat Fossil fuel availability Category Indicators Local effects on species Climate change Ozone layer depletion Radiation Respiratory effects Cancer cases and types Surplus energy Damage Categories Single Score Indicator Fate analysis Exposure & effect analysis Damage analysis Normalization & weighting Mineral & Fossil Resources Ecosystem Quality Human Health Impact Assessment
Total Normalized Impact
Normalized Environmental Impact
Step 4: Report Results Life cycle interpretation: findings of the inventory analysis or impact assessment are evaluated in relation to the goal and scope of the study to reach conclusions and recommendations 1.Identify significant issues 2.Evaluate results for completeness, consistency, and sensitivity of the data 3.Draw conclusions & make recommendations consistent with the goal & scope of the study
Interpreting Results Which bag has the lowest environmental impact? Which bag has the highest? Let’s consider cost of the bags. As the store owner, does the cost information change which type of bag you would promote? How? As a shopper, does the cost information change which type of bag you would use? How? Bag TypeSingle use plasticSingle use paperReusable plasticReusable cotton MaterialHDPEUnbleached Kraft paperPolypropyleneCotton Cost per bag$0.02$0.07$1$6 Cost per year$10.40$40.46$4.55$27.30
Anahita Williamson, PhD Director Phone: Kate Winnebeck, LCACP Sr. Environmental Health & Safety Specialist Phone: New York State Pollution Prevention Institute