2_Symposium LCA 2017_AmlanMukherjee

Symposium Measuring Asphalt Industry Sustainability Amlan Mukherjee, PhD Associate Professor, Michigan Technological University Heather Dylla, PhD Director of Sustainability National Asphalt Pavement Association Outline  Life Cycle Assessment (LCA) supporting the Product Category Rules (PCR)  Scope  Declared Unit  System Boundaries  Data Types: Trends in Primary Data  Pointers towards improving plant sustainability Product Category Rules A set of defensible rules for a LCA:  Compliant with ISO 14044/14025  Allows consistent estimation of impacts across industries Identify the following:  The scope of the product: HMA + ?  System boundary: how far upstream we go?  Data: sources and integrity The declared unit: US Ton of Asphalt Mixture  Not functional unit Challenges in Defining Scope Motivating question: Should the EPD certify one representative mix for all mixes from a plant, or should each specific mix have an EPD? What about different kinds of mixes? Challenges in Defining Scope Product scope: asphalt mixture  Only Hot or Warm Mix  Families of mix designs  Modified asphalts  Quicklime/Lime treatment  Warm mix additives  Recycled materials Meeting DOT specifications Defining System Boundary Motivating question: What is the System Boundary for the proposed LCA? Various challenges  Exclusion criteria  Allocation Data sources Guiding question What producers have control over? Life Cycle Perspective Cradle-to-Gate: A1-A3 Data Types Upstream Data: Raw materials and transportation  Spans across disparate supply chains Plant Operations Data  Directly reported by plant managers – energy, mix, product specification  Sometimes transportation data included Bitumen Production Process Energy Source Extracted Crude Oil Raw Material Barge Transportation Refining Process Polymer Modification Ground Tire Rubber We need a Binder placeholder EPDwhile AI develops IssuedLCA by AI 1.00 kg of Petroleum Binder + Co Products Asphalt Mixture EPD Virgin Aggregate Energy Source (Fuel, Gasoline, Electricity) Primary Data Extraction/ Mining Aggregate Processing Transportation Raw Material  Portland Cement Association - Fuel/Electricity Inputs – Sand and Gravel production: 19,940 Btu/ton – Coarse Aggregate from crushed stone: 30,469 Btu/ton 10 Recycled Aggregate Energy Source (Fuel, Gasoline, Electricity) Not Included Previous life Processing Transportation RAP/RAS Recycled Material  Cut-off allocation method  RAP Production: (Loader, Grinder & Screen) – EPA Study: 20 gal/hr (diesel) @ 350 ton/hr ~ 56,397 Btu/ton  RAS Production: (Loader, Grinder) – EPA Study: 35 gal/hr (diesel) @ 53 ton/hr ~ 200,000 Btu/ton 11 Challenges: Upstream Data Availability  US LCI data is limited  Open and freely available vs proprietary data  Transparency of datasets  Reliability: consistency across shared system boundaries Appropriateness  Programmatic issues regarding access  Comparability of LCA outcomes 12 Number of Plants Surveyed Excel spreadsheets provided to plants Plant visits: personal meetings with plant managers 51 plants from different regions  Plant operating energy consumption  Electricity  Natural gas  Other fuels  Plant emissions (estimated using AP-42 – reported by plants)  Plant production rate (tons/hour) and efficiency  Plant water usage: dust control and as additive  Mix design and percentage production 13 Primary Data Trends: Electricity Electricity (kWh) vs Total Produc on (US Ton) 1.00E+07 Av Electricity kWh/ton 4.50E+00 Electricity use: kWh 4.00E+00 North Central - Electricity Midwest/GP - Electricity 3.50E+00 Northeast - Electricity 1.00E+06 Northwest - Electricity 3.00E+00 Southeast - Electricity Southwest - Electricity 2.50E+00 Mid-Atlan c: Electricity Av Electricity kWh/ton 2.00E+00 1.50E+00 1.00E+00 1.00E+05 0.00E+00 5.00E-01 1.00E+05 2.00E+05 3.00E+05 4.00E+05 5.00E+05 6.00E+05 7.00E+05 Total Plant Produc on - Ton 0.00E+00 NE 14 CN MW MA NW SW Primary Data Trends: Energy Total Energy (BTU) vs Total Plant Produc on (US Ton) 1.00E+12 Average Energy Btu/ton 3.50E+05 3.00E+05 Total Energy Use: BTU 1.00E+11 Northcentral Midwest/GP 2.50E+05 Northeast Northwest 2.00E+05 Southeast 1.00E+10 Southwest 1.50E+05 Mid-Atlan nc 1.00E+05 1.00E+09 0.00E+00 5.00E+04 1.00E+05 2.00E+05 3.00E+05 4.00E+05 5.00E+05 6.00E+05 7.00E+05 Total Plant Produc on - Ton 0.00E+00 NE 15 CN MW MA NW SW Average Energy Btu/ton Data Trends: Aggregate Production Energy Electricity 16 Mix Family Definition Reference a baseline virgin mix Reduction in virgin binder content by 50%  Either by RAP introduction  Or by RAP + RAS introduction Families defined by initial virgin mix binder content  5% virgin mix  8% virgin mix 17 Reduction in GWP / 1% reduction in binder content 35 5% Virgin Mix % Reduc on in GWP - kg of CO2 Eq 30 8% Virgin Mix 25 20 5% Ini al Virgin Mix 15 8% Ini al Virgin Mix 10 0.00% 0.50% 1.00% 1.50% 2.00% % Asphalt Binder Replacement 18 5% Virgin Mix - 11.4% - by RAP - 10.9% - by RAP+RAS 2.50% 3.00% 3.50% 8% Virgin Mix - 8.8% - by RAP - 8.4% - by RAP+RAS Summary A PCR was developed for Asphalt Mixtures  Challenges with scope and system boundaries addressed Challenges with upstream life cycle inventory data  Need for transparency and completeness Primary data was collected from 51 plants in the US  There are meaningful trends in use patterns  Foundations of a tool for influencing design 19 Thank You 20 ...Outline  Life Cycle Assessment (LCA) supporting the Product Category Rules (PCR)  Scope  Declared Unit  System Boundaries  Data... Pointers towards improving plant sustainability Product Category Rules A set of defensible rules for a LCA:  Compliant with ISO 14044/14025  Allows consistent estimation of impacts across industries... specifications Defining System Boundary Motivating question: What is the System Boundary for the proposed LCA? Various challenges  Exclusion criteria  Allocation Data sources Guiding question What producers