Comparison of Cradle-to-Grave GHG Emissions among Spray Foam Expansion Agents

Transcription

1 Comparison of Cradle-to-Grave GHG Emissions among Spray Foam Expansion Agents

2 Outline 2 Goal & Scope of Study Spray Foam Formulation Installation Use/End-of-Life Emissions Use-Phase Energy Savings Sensitivity Analysis Conclusions & Future Work

3 Goal and Scope of Study 3 Goal Compare lifecycle greenhouse gas emissions (GHG) of various spray polyurethane foams (SPFs) and highlight areas having significant influence on overall results Evaluate the effect of foam expansion agent (FEA) selection and usage rate (FEA loading) on lifecycle GHG emissions

4 4 Goal and Scope of Study, con t Scope Application: Residential wall FEAs Studied: HFC-141b, HFC-245fa, FEA-1100 Geography: Baltimore, MD Chicago, IL Houston, TX FEA Loading: Low: 3-6 wt% FEA (as wt% of total A & B side) Mid: 6-9 wt% FEA Low: 9-12 wt% FEA Impacts studied: Climate change potential (as measured by lb CO 2 eq per Intergovernmental Panel on Climate Change, IPCC 4 th edition)

5 Goal and Scope of Study, con t 5 Functional Unit The functional unit of an LCA incorporates the functionality of the product studied and is the basis for lifecycle impacts and comparisons among spray polyurethane foams (SPFs) All SPFs are compared on a square-foot basis, but additionally they are compared using the following functional basis: 1. Equal R-value Basis: R-value constant (R-13), vary thickness 2. Equal Thickness Basis: Thickness constant (3.5 inches), vary R-value

6 Goal and Scope of Study, con t 6 System Boundaries Cradle-to-Grave System Boundaries Emissions Energy Raw Material #1 Manufacturing Natural Resources Raw Material #2 Manufacturing Raw Material #3 Manufacturing Raw Material #4 Manufacturing SPF Formulation Manufacturing SPF Installation SPF Use SPF End-of-Life

7 7 Typical Spray Foam Formulations Isocyanate (MDI) Polyol Spray Foam Formulation (A-Side) Foam Exp Agent Formulation to Installer Fire Retardant Spray Foam Formulation (B-Side) Catalyst Surfactant

8 Formulation Data Collection & Results 8 Data collected from formulators Key Information: Raw material inputs Amount of Polyol, FEA, Isocyanate Ranges specified for Catalyst, Fire Retardant, Surfactant Performance inputs R-value per inch Foam density Data organized into groups and aggregated by: FEA used (HFC-141b, HFC-245fa, FEA-1100) FEA loading (low, mid, high) Cradle-to-Gate (CTG) GHG emissions Ranged from 3.0 to 5.5 lb CO2 eq per lb formulation Largest contributors were isocyanate, polyol and FEA manufacturing

9 9 Spray Foam Installation Direct FEA Emissions 10% of Initial FEA in Formulation Spray Foam Formulation (A-Side) Installation SPF Use Spray Foam Formulation (B-Side) Direct FEA Emissions 5 wt% of Installed Foam Foam Waste

10 Installation Data Collection & Results 10 Key Information: Amount of formulation per functional unit Thickness and foam density determine the amount (in pounds) of each formulation Direct emissions of FEA during installation Assumed to be 10 wt% of initial FEA in formulation Amount of SPF discarded as waste after installation Assumed to be 5 wt% of total SPF installed Includes direct FEA emissions from discarded SPF Electricity consumed during installation was assumed to be negligible based on hot-spot analysis

11 11 Installation Data Collection & Results, con t Lifecycle GHG Emissions through Installation [lb CO 2 eq per ft 2 foam insulation] HFC-141b HFC-245fa Yield Loss during Installation FEA Emissions during Installation Formulation Manufacturing FEA Mid (6-9wt%) Low (3-6wt%) Mid (6-9wt%) High (9-12wt%) Low (3-6wt%) Mid (6-9wt%) High (9-12wt%)

12 12 Add results for 2 nd functional unit? Lifecycle GHG Emissions through Installation [lb CO 2 eq per ft 2 foam insulation] HFC-141b HFC-245fa Yield Loss during Installation FEA Emissions during Installation Formulation Manufacturing FEA Mid (6-9wt%) Low (3-6wt%) Mid (6-9wt%) High (9-12wt%) Low (3-6wt%) Mid (6-9wt%) High (9-12wt%)

13 Direct FEA Emissions during Use & End-of-Life 13 FEA is assumed to leak during lifetime of the foam and end-of-life Direct FEA emissions based on several sources A.D. Little:..highly conservative assumption is made that 75% of the initial blowing agent is emitted within a relevant time scale. L.D. Harvey: % emitted/year (60-75% over 50 years) If the building and the insulation placed in a landfill, then essentially all of the remaining blowing agent will reach the atmosphere. Bio, 2011: 69% Emitted during lifetime In this evaluation it was assumed that 75% of the initial FEA is emitted during SPF use and end-of-life A sensitivity is performed that evaluates the affect of this assumption on the overall results

14 14 Lifecycle GHG emissions (excluding energy savings) Cradle-to-Grave GHG Emissions w/o Energy Savings [lb CO 2 eq/ft 2 foam insulation] HFC-141b HFC-245fa FEA Emissions during Use and End-of-Life Yield Loss during Installation FEA Emissions during Installation Formulation Manufacturing FEA-1100 Mid (6-9wt%) Low (3-6wt%) Mid (6-9wt%) High (9-12wt%) Low (3-6wt%) Mid (6-9wt%) High (9-12wt%)

15 15 2 nd functional unit? Cradle-to-Grave GHG Emissions w/o Energy Savings [lb CO 2 eq/ft 2 foam insulation] HFC-141b HFC-245fa FEA Emissions during Use and End-of-Life Yield Loss during Installation FEA Emissions during Installation Formulation Manufacturing FEA-1100 Mid (6-9wt%) Low (3-6wt%) Mid (6-9wt%) High (9-12wt%) Low (3-6wt%) Mid (6-9wt%) High (9-12wt%)

16 Energy Savings during SPF Lifetime 16 All insulations seek to reduce energy usage by reducing heat transfer through a medium To quantity energy savings from SPF use, one could: Energy use w/o SPF Insulation Energy use w/spf Insulation - = Energy savings from SPF Insulation However.. In typical residential applications insulation is generally used, making the no insulation scenario somewhat unrepresentative The above scenario may quantify the benefit of using insulation (versus no insulation), but in this study we seek to compare among typical SPFs

17 Energy Savings during SPF Lifetime, con t 17 In this evaluation, energy savings from SPF use were calculated as incremental differences from a common SPF baseline: Energy use w/ HFC-141b SPF Energy use w/ specific SPF - = Incremental energy savings as compared to HFC-141b baseline

18 Energy Savings during SPF Lifetime, con t 18 Trane s TRACE 700 software used to perform energy modeling Typical 2-story residential dimensions/parameters used Key Inputs 50 year SPF Insulation Lifetime (use) Baltimore, Chicago and Houston geographies were modeled Cooling demand modeled as 100% electricity Heating demand modeled as 58% natural gas, 34% electricity, 7% heating oil. Cradle-to-gate GHG emissions for energy savings Based on US-average supply chains 500 lb CO 2 eq per MMBtu cooling load 290 lb CO 2 eq per MMBtu heating load

19 19 Lifecycle GHG Emissions: Equal R-Value basis, as compared to HFC-141b SPF 10 HFC-245fa FEA Cradle-to-Grave GHG Emissions [lb CO 2 eq per ft 2 foam insulation] Energy Savings FEA Emissions during Use and End-of-Life Yield Loss during Installation FEA Emissions during Installation Formulation Manufacturing -25 Low (3-6wt%) Mid (6-9wt%) High (9-12wt%) Low (3-6wt%) Mid (6-9wt%) High (9-12wt%)

20 20 Lifecycle GHG Emissions: Equal Thickness basis, as compared to HFC-141b SPF 20 HFC-245fa FEA Cradle-to-Grave GHG Emissions [lb CO 2 eq per ft 2 foam insulation] Energy Savings FEA Emissions during Use and End-of-Life Yield Loss during Installation FEA Emissions during Installation Formulation Manufacturing -50 Low (3-6wt%) Mid (6-9wt%) High (9-12wt%) Low (3-6wt%) Mid (6-9wt%) High (9-12wt%)

21 Conclusions 21 When evaluating the lifecycle climate change potential of spray polyurethane foams in residential wall applications, the GWP of the FEA used can significantly influence relative results. In this application, FEA-1100 has superior lifecycle climate change performance than HFC-141b and HFC- 245fa, largely due to difference in FEA GWP. Other variables, such as geography and %FEA loading can also affect results; however, in an sensitivities evaluated, FEA-1100 had superior lifecycle climate change performance.

22 Future Work 22 Extend the scope of this study to include addition applications for FEA-1100, as relative benefits are specific to particular applications and competitive landscape. Obtain external peer-review for this study and subsequent LCA studies

23 23 Background Slides

24 24 References International Code Council International Energy Conservation Code. Intergovernmental Panel on Climate Change (IPCC) Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. IPCC, Geneva, Switzerland, 104 pp. Technical University of Denmark (DTU), supported by the European Commission Joint Research Centre International Life Cycle Data System (ILCD) Handbook, General Guidance Document for Life Cycle Assessment. National Renewable Energy Laboratory (NREL) US Lifecycle Inventory Database (USLCI). Latest revision Association of European Plastic Industry. 2005, Eco-Profiles of the European Plastic Industry. Ecoinvent Centre Ecoinvent data v 2.0, Final reports ecoinvent 2000 No U.S. Patent 6,303, Separating 1,1,1,3,3-Pentafluoropropane from Hydrogen Fluoride. SRI Reports Process Economics Program Report No. 201, Chlorofluorocarbon Alternatives. L.D. Danny Harvey Net climatic impact of solid foam insulation produced with halocarbon and non-halocarbon blowing agents, Building and Environment.,42(2007): A.D. Little Global Comparative Analysis of HFC and Alternative Technologies for Refrigeration, Air Conditioning, Foam, Solvent, Aerosol Propellant, and Fire Protection Applications. National Oceanic and Atmospheric Administration (NOAA). Preliminary Laboratory Results and Radiative Properties for E- and Z-1,1,1,4,4,4-hexafluoro-2-butene. Bio Intelligence Service in coordination with the European Commission (DG ENV) Service Contract on Management of Construction and Demolition Waste- SR1. US Environmental Protection Agency (EPA), AP 42, Volume I, 5th Edition.