Environmental Life Cycle Assessment PSE 476/WPS 576/WPS

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1 Environmental Life Cycle Assessment PSE 476/WPS 576/WPS Lecture 10: End of Life Richard Venditti Fall 2012 Richard A. Venditti Forest Biomaterials North Carolina State University Raleigh, NC Richard_Venditti@ncsu.edu Go.ncsu.edu/venditti

2 Waste Hierarchy

3 Reduce, re-use, recycle. Example: want to understand the burdens of containing groceries during transport Reduce: don t use a bag, 0 burden/trip Re-use (production of bag = 1 burden) Use bag once, 1 burden/trip Use bag twice, 0.5 burden/trip Use bag 3x, 0.33 burden/trip Recycle (to recycle costs 0.4 burdens, arbitrary) Then for using the bag and recycling once: ( ) / 2 trips = 0.7 burdens/trip (data for example only, not meant to represent an actual process) 3

4 Types of waste. Biodegradable waste: food and kitchen waste, green waste, paper (can also be recycled). Can be broken down, in a reasonable amount of time, into its base compounds by microorganisms and other living things, regardless of what those compounds may be. Recyclable material: paper, glass, bottles, cans, metals, certain plastics, fabrics, clothes, batteries etc. Inert waste: construction and demolition waste, dirt, rocks, debris. Will not degrade due to microbial decomposition. Electrical and electronic waste (WEEE) - electrical appliances, TVs, computers, screens, etc. Composite wastes: waste clothing, Tetra Packs, waste plastics such as toys. Hazardous waste including most paints, chemicals, light bulbs, fluorescent tubes, spray cans, fertilizer and containers Toxic waste including pesticide, herbicides, fungicides Medical waste.

5 Municipal solid waste? MSW: everyday items that are discarded by the public Also referred to as trash, or rubbish Includes packaging, food scraps, grass clippings, sofas, computers, tires and refrigerators, for example. Does not include industrial, hazardous, or construction waste.

6 Trends in U.S. Waste Generation Adopted from EPA 2011 MSW Facts and Figures

7 Trends in U.S. Waste Recycling Adopted from EPA 2011 MSW Facts and Figures

8 Current U.S. waste treatment 20 million tons % 29 million tons % % 136 million tons % Total: 250 million tons 65 million tons Adopted from EPA 2011 MSW Facts and Figures 8

9 Source of MSW? Residential waste (houses and apartments): 55-65% of total MSW generation Commercial and institutional locations (businesses, schools, hospitals..): 35-45%

10 Materials in MSW? Dominated by organic matter, biodegradable

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12 Products in MSW?

13 Durable vs non-durable goods. A durable good or a hard good is a good that does not quickly wear out, or more specifically, one that yields utility over time rather than being completely consumed in one use. Examples: Bricks, refrigerators, cars, or mobile phones, cars, household goods (home appliances, consumer electronics, furniture, etc.), sports equipment, and toys. Nondurable goods or soft goods (consumables) are immediately consumed in one use or ones that have a lifespan of less than 3 years. Examples: cosmetics and cleaning products, food, fuel, beer, cigarettes, medication, office supplies, packaging and containers, paper and paper products, personal products, rubber, plastics, textiles, clothing and footwear. Source: Wikipedia

14 Products, Million tons, 2010

15 Products, Million tons, 2010

16 Recycling Rates of Selected Products Adopted from EPA 2011 MSW Facts and Figures

17 Products with highest % recovery. Lead acid batteries, 96% Corrugated boxes, 85% Newspapers, 72% Steel packaging, 69% Major appliances, 65% Yard trimmings, 58% Aluminum cans, 50% Mixed paper, 45% Source: Wikipedia

18 Landfill: an introduction

19 Landfill Cross Section (simplified) Monitoring Wells Vegetation Cover System Gas Collection Waste Leachate Collection System Liner System Water Table Morton Barlaz, CE, NCSU

20 CO2, Energy Offset Carbon Flow In Landfills Emissions Capture Fugitive Gas (CH4, CO2, VOCs) Decomposing Waste Residential Industrial Commercial Biosolids Stored Carbon Leachate (CO 2, VOCs) Morton Barlaz, CE, NCSU

21 Carbon Footprint CO 2 e = fugitive methane emissions + emissions associated with construction, operation, post-closure and leachate treatment - avoided emissions from energy recovery - carbon storage Notice: CO2 emissions from decay are not counted (biogenic). Fugitive methane emissions = CH4 prodn. * (100- % collected) * (100- % oxidized) Morton Barlaz, CE, NCSU

22 Biodegradable Substrates Paper, yard waste and food waste are comprised of cellulose and hemicellulose These compounds are converted to CH 4 and CO 2 by bacteria under anaerobic conditions Several groups of bacteria are involved Morton Barlaz, CE, NCSU 22

23 Refuse Decomposition Refuse decomposition is affected by: Climate, surface hydrology, ph, temperature, operations Exerts an influence on: Gas composition and volume Leachate composition 23 Morton Barlaz, CE, NCSU

24 CH4 yield (M 3 CH4/dry Mg) Reactor Data: Methane Yields Cellulose: (C150 6 H 10 O 5 ) n + nh 2 O 3n CO 2 + 3n CH Hemicellulose: (C 5 H 8 O 4 ) n + nh 2 O 2.5n CO n CH 4 Newsprint Office OCC Coated Paper Branches Grass Leaves Food Hardwood Softwood Plywood (SW) Morton Barlaz, CE, NCSU OSB Particle Board Medium Density Fiberboard

25 Methane Rate (m3/yr) Methane Production Rate Curve for One Year of Waste 3.00E E E E E E E Time (Yr) Based on 286,000 short tons of refuse at time zero Copyright Morton A. Barlaz, and NC State Lo = 1.5 ft 3 /wet lb ( m 3 /wet Mg) University

26 An example: Paper Recycling Paper is collected and sometimes sorted The paper is slushed into water, separating fibers, pulping Contaminants are removed Screening Centrifugation Washing Bleaching Others Fibers are then remade into paper Source: afandpa.org, 2011

27 US Paper Recycling Recovery Rate: 1999 Total Paper Consumption: 105 million tons Total Paper Recovered: 47 million tons Recovery Rate: = 45% 2004 Total Paper Consumption: 102 million tons Total Paper Recovered: 50 million tons Recovery Rate: = 49% 2011 Total Paper Consumption: 79 million tons Total Paper Recovered: 53 million tons Recovery Rate: = 66.8% Source: afandpa.org, 2011

28 Paper/board Recovery Rate in the US: Record high 66.8% RR. Paper purchases declined (2.3 million tons) while recovered paper increased 1.3 million tons. Source: afandpa.org, 2012

29 Recovered and Landfilled Paper Source: afandpa.org, 2012

30 Where Recovered Paper Goes: Source: afandpa.org, 2012

31 Recovery of Corrugated Containers (OCC) 19 MMT used domestically, 8 MMT exported, Purchases increased 7.2% in 2010, Recovered OCC increased by 11.2% Source: afandpa.org, 2012

32 Recovery of Old Newspapers (ONP) Includes ONP, uncoated mechanical, and coated ONP inserts. 7.5% decrease in consumption of ONP Source: afandpa.org, 2012

33 Recovery of Printing-Writing Papers Purchases of PW Papers declined by 5%. Source: afandpa.org, 2012

34 End of Life Example: Catalog Paper Carbon footprint

35 End of life: Catalog Paper Source: NCASI

36 End of life: Printing and Writing Papers Table 4-5. End-of-Life of Printing and Writing Paper Products Paper product Recovery Landfill * Burning and energy recovery * Office paper 71.8% 23.0% 5.2% Catalog 32.7% 54.8% 12.5% Telephone directory 19.1% 65.9% 15.0% Magazine 38.6% 50.0% 11.4% * Landfill and burning and energy recovery ratios are based on U.S. average for all municipal solid waste in 2006 (81.4% landfilled, 18.4% incinerated).

37 Life Cycle Inventory: End of Life: Carbon in Products How much carbon exists in products. Needed for end of life and carbon storage in products. Half life, number of years for the existing paper in use to halve itself C permanently stored (in landfills) Product Carbon content (fraction) Half-life (years) Carbon permanently stored (fraction) bleached kraft board bleached kraft paper (packaging & industrial) 0.61 coated mechanical coated woodfree average containerboard newsprint recycled boxboard recycled corrugating medium

38 32.7% to Recycle 12.5% Burning with Energy Recovery Emissions Methane 54.8% to Landfill X % stored as permanent Carbon (100yrs) CO2 Burnt for Electicity

39 How important is end of life? Carbon in mill landfills from manufacturing wastes (kg CO2 eq./boc) Carbon in landfills from products at end of life (kg CO2 eq./boc) Carbon in products in use (kg CO2 eq./boc) Changes in forest carbon (kg CO2 eq./boc) Ctd Mech Ctd Free Total carbon storage changes (kg CO2 eq./boc) Emissions from end of life (including transport) Emissions from product transport Emissions from manufacturing wastes Emissions from other raw materials (including transport) Emissions from wood and fiber production (including transport) Emissions from purchased electricity and steam Emissions from fuel used in manufacturing (including transport) Of which, total transport (includes all transport components): Total emissions, including transport (kg CO2 eq./boc): Carbon footprint (kg CO2 eq./boc)

40 How important is end of life? (ctd free = catalog) End of Life Fuel Mfg

41 Paper Recycling: Other environmental impacts (avoid parts thinking):

42 Life Cycle Inventory: End of Life Allocations in recycling.

43 Two Main Allocation Situations: Recycling Allocation: a virgin product is recycled or reused in a subsequent life There exists operations that are required by the virgin and the recycled products (shared operations) Example shared operations: virgin raw material production, final disposal Many ways to allocate the burdens of the common operations Open loop recycling allocation is the most controversial issue in LCA currently!!!! 43

44 Closed and Open Loop Recycling: Closed loop: material or products are returned to the same system after use and used for the same purpose again (Baumann, Tillman, 2004) Open loop: a product is recycled into a different product Production of P Use Product Disposal Recover Production of P Use of Product A Disposal Recover Production of Product B Disposal 44

45 Allocation Methods in LCA: Example: virgin paper recycled twice and then disposed. Closed loop recycling example with products P1, P2, and P3. Primary material production (V 1 ) Production of Product P1 (P 1 ) Recycling of Product P1 (R 1 ) Production of Product P2 (P 2 ) Recycling of Product P2 (R 2 ) Production of Product P3 (P 3 ) Use of Product P1 (U 1 ) Use of Product P2 (U 2 ) Use of Product P3 (U 3 ) End of life (W 3 ) 45

46 Allocation Methods in LCA: Example: virgin paper recycled twice and then disposed. Closed loop recycling example. CO2e Lb/ton product Raw Matl Virgin Prod Collect/transp Recycle Process Collect/transp Recycle Process Waste Mgmt V1 P1 R1 P2 R2 P3 W3 Shared Operation Potentially Shared Operation Potentially Shared Operation Not Shared Operation Potentially Shared Operation Not Shared Operation Shared Operation CO2e ton/ton product Table 7. Net GHG of office paper from various life cycle stages from the Paper Task Force (2002, pg. 132), waste management is 80/20 landfill/incinerate. 46

47 Net GHG, lb CO2eq/ton Allocation Methods in LCA: Choice of allocation method determines whether virgin or recycled products are promoted: Recycled result is the average of products 2 and Virgin Burden Recycled Burden Paper Task Force 5000 Shared Burden Cutoff MLWMBR 50/50 Closed Loop Recycling Quality Loss RMAGWT 47

48 Homework assignment #6 Using the methods described in HHG to LCA, page , verify the preceding results. Show the individual results of product 1, 2 and 3 and also the average of the two recycled products, 2 and 3, which is the data that appears in the bar graph. Show all work.

49 Waste management hierarchy Biodegradable waste Inert waste Municipal solid waste Durable goods Non-durable goods Fugitive Methane Emissions Steps in Paper Recycling Recovery Rate Closed loop recycling Open loop recycling Shared operations Allocation Summary