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Chapter 2. Life Cycle Analysis (LCA)

1. Introduction

• LCA is an analysis to trace the flows of energy,raw materials, and waste streams that were,required to create, use and dispose of the product.

• It is a systematic tool for assessing theenvironmental impacts associated with a productor service system.

• A central characteristic of life cycle assessment is

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ce c c e s c o e cyc e ssess e sthe holistic focus on products or processes andtheir functions, considering upstream anddownstream activities.

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Chlorine

Vent light ends

EDC recycle

NaOH solution

A typical VCM manufacturing process (Gate-to-Gate)

Directchlorination reactor

NeutralizationEDC

pyrolysisVCM

purification

Ethylene

Heavy ends

HCl recycle

Crude EDC

VCM product

Flue gas vent

EDCpurification

Aqueous stream

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Oxychlorinationreactor

Decanter

Air

H2O

Condenser

Recycle

Global VCM process (Cradle-to-Gate)

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3

Cradle-to-Grave

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LIFE CYCLE ASSESSMENT - LCARAW MATERIALS

ENERGY CO NVERSION

EXTRACTION

MW

W

M

M

E

2

MATERIALPURIFICATION

MANUFACTURINGPROCESS

USE

M

W

M

W

M

W

E

E

E

1

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RECYCLE

DISPOSAL ORRECYCLING

MM

EW

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I - Integrated Pollution Control (IPC) 2 - LCA

M - Materials; E - Energy; W - Wastes and emissions

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ISO14000 LCA standards• Goal and scope definition (ISO-14040, 14041)

Define the goal and intended use of the LCA, and th t i tscopes the assessment concerning system

boundaries, function and flow, required data quality, technology and assessment parameters.

• Life Cycle Inventory analysis, LCI (ISO-14041)

Collect data on inputs (resources and intermediate d t ) d t t ( i i t ) f ll

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products) and outputs (emissions, wastes) for all the processes in the product system.

ISO14000 elements (continued)• Life Cycle Impact Assessment, LCIA (ISO-14042)

Translate inventory data on inputs and outputs into i di t b t th d t t ’ t ti lindicators about the product system’s potential impacts on the environment, on human health, and on the availability of natural resources.

• Interpretation (ISO-14043)

The results of the LCI and LCIA are interpreted di t th l f th t d d h

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according to the goal of the study and where sensitivity and uncertainty analysis are performed to qualify the results and the conclusions. Not all LCA's include this step.

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ISO14000: A LCA framework

Goal & scopedefinition

Inventory &analysis

definition

Interpretation

Applications:•Product development& improvement

•Strategic planning•Public policy making•Marketing

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Impactassessment

Marketing•Others

2. Standard procedures for a LCA

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a. Goal and scope• The system function and functional unit: the

economic or social good provided by the goods or i i ti ( l t i l )services in question. (e.g. electrical cars)

• Impact categories: which environmental concerns are included and which are excluded. (e.g. global warming, smog formation)

• The system boundary: which processes are

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included and which ones are excluded. (e.g. municipal waste disposal)

• The audience: whether it will be a public and peer reviewed document. (e.g. published paper or report)

Global VCM process (Cradle-to-Gate)

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b. Life-cycle inventories & analysis

A life-cycle audit is conducted on each stages of product or each unit within the defined boundaries to obtain a life-cycle inventory of wastes, emissions, energy consumption, water consumption and costs

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for the product.

FOREGROUND SYSTEM:

Set of processes whose selection or mode of operation

is affected directly by decisions based on the studyis affected directly by decisions based on the study.

BACKGROUND SYSTEM:

All other processes which interact directly with the foreground system, usually by supplying material or energy to the foreground or receiving material energy from it A

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the foreground or receiving material energy from it. A sufficient (but not necessary) condition for a process or group of processes to be in the background is that the exchange with the foreground takes place through a homogeneous market.

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FOREGROUND AND BACKGROUND (SUB-) SYSTEMS

BackgroundIndirect

GHG emissions

Direct

GHG emissions

sub-system

Foreground

b t

Energy (and energy carriers)Materials

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GHG emissionssub-system

Product or service

Global VCM process (Cradle-to-Gate)

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Key issues in LCI

• How to select a functional unitHow to select a functional unit– Used to connect social benefits (goods and services) to

environmental impacts

• How to allocate emissions and resources to multiple products

• How to consider recycling at the end of product lif

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life• How to quantify the land use and water use• Specific data vs. average data

c. Life-cycle impact assessment• Impact Assessment aggregates inventory data to

indicators for each impact category. • A typical list of impact indicators includes:yp p

– Global Climate Change – Stratospheric Ozone Depletion – Smog formation – Acidification – Eutrophication

Human Toxicity

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– Human Toxicity – Ecotoxicity – Natural Resource depletion (habitat, water, fossil fuels,

minerals, biological resources) – Land use and biodiversity

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IMPACT CATEGORIES

RESOURCES:

Abiotic Depletion Potential

Energy Depletion Potential

EMISSIONS:

Global: Global Warming Potential

Ozone Depletion Potential

Regional/local: Acidification Potential

Photochemical Oxidant

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Smog formation potential

Human Toxicity

Aquatic/Terrestrial Ecotoxicity

Nutrification Potential

RESOURCE DEPLETION

Abiotic Depletion Potential: extraction of non-Abiotic Depletion Potential: extraction of nonrenewable raw materials such as ores.

Energy Depletion Potential: extraction of non-renewable energy carriers; can be included in

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Abiotic Depletion Potential.

Issues: weighting to reflect scarcity value?

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GLOBAL ENVIRONMENTAL IMPACTS

Global Warming Potential: contribution toGlobal Warming Potential: contribution to atmospheric absorption of infra-red radiation leading to increase in mean global

temperature.

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Ozone Depletion Potential: contribution to depletion of stratospheric ozone, leading to increase in ultraviolet radiation reaching earth’s surface.

REGIONAL & LOCAL ENVIRONMENTAL IMPACTS: I - PHYSICO-CHEMICAL

Acidification Potential: contribution to acid deposition onto soil and into water.

Smog Formation Potential: contribution to formation of tropospheric (i.e. ground

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to formation of tropospheric (i.e. ground level) ozone.

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REGIONAL & LOCAL ENVIRONMENTAL IMPACTS: II - BIOLOGICAL

Human Toxicity: contribution to human health problems through exposure to toxic substancesproblems through exposure to toxic substances via air, water or soil (especially through the food chain).

Aquatic/Terrestrial Ecotoxicity: contribution to health problems in flora and fauna caused by exposure to toxic substances.

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pEutrophication Potential: contribution to

reduction of oxygen concentration in water (or soil) through providing nutrients which increase production of biomass.

LIFE CYCLE IMPACT ASSESSMENT - LCIA

Classification Characterisation ValuationInventory

2CO

CFCs

HCFCs

CH 4

HC

Global warming

Ozone layerdepletion

Photochemicaloxidant formation

GWP

ODP

POCP

Ranking ofenvironmental

impacts (weightingfactors)

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NOx

SO2

HClAcidification AP

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d. Interpretation

• Use normalization, scoring and other methods to clarify data for decision makersy

• Review data quality (e.g. uncertainty, confidence level)

• Make recommendations

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3. Applications of LCA

a. Green product and process design, development and improvement

• Identify green pathways for a new product

• Identify “hotspot” in the life cycle chain of i ti d t

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an existing product or process

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Raw material acquisition

Environment

Pollution prevention Material manufacture

Renewability

Sustainability

Product use

Clean production

Product manufactureIndustrial Ecology

Health impact

Green Engineering

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Product use

Product disposal

Environment

Health impact

Degradability

Eco-toxicity

Clean technologies for cloth cleaning

28Franklin Associates Ltd., (1993)

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LCA observations

For washing machine manufacturerFor washing machine manufacturer

Problem: major energy and water consumption in the stage of product use.

Solutions: Make machines which use less energy and water.

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LCA observations

For cloth manufacturer

Problem: Major energy consumption in the stageProblem: Major energy consumption in the stage of product use (warm washing and drying).

Solutions: Manufacture cold water washable and fast dryable cloth.

For detergent producer

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For detergent producer

Problem: Major impact on the environment from the direct discharge of the spent detergent.

Solutions: Cold water usable, biodegradable easily

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b. Product comparisons

• Life-cycle inventories and life-cycle assessments have been used to compareassessments have been used to compare products that serve similar functions, although great controversies still exist on the use of life-cycle inventories and life-cycle assessment for product comparison.

• Examples:

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• Examples:– Paper vs. plastic bags– Wood/bamboo chopsticks vs. plastic spoons– Plastic cups vs. paper cups

Key issues in LCIA for product comparison

• Equivalency of products for comparison– Electric cars vs. gasoline combustion engine cars

– Paper vs. plastic bags

– Cloth diapers vs. disposable diapers

• Renewable versus non-renewable source– Paper bags vs. plastic bags

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• Biodegradable versus non-biodegradable product at the end of their lives.– Paper bags vs. plastic bags

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Table 3. A life cycle ranking of milk and juice packaging alternatives (Spitzley et al., 1997).

P2 Options Energy use(16.7%)

Solid waste(16.7%)

Cost(33.3%)

Performance(33.3%)

Overall Score*

Flexible pouch 2.1 0.14 1.1 6.2 2.8

Gable top carton 10 1.1 1.8 5.0 4.1

Class bottle (Refillable)(Single use)

4.98.8

1.110.0

1.210.0

10.07.5

4.79.0

HDPE bottle

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(Refillable)(Single use)

2.99.7

0.050.55

0.73.4

3.81.2

2.03.2

Polycarbonate 3.3 0.04 1.0 5.0 2.6

*Overall score = 1/3*(1/2*Energy use + 1/2*solids waste) +1/3*cost + 1/3*performance

Example 1: A life cycle cost (LCC) comparison betweengalvanized carbon steel and stainless steel was conductedon the highway bridge by including the capital cost andoperating cost incurring over the whole life-cycle of thebridge (Leslie, 1999). As shown in Table 2, the initial

t f b t l b id i h th th t i lcost for carbon steel bridge is cheaper than the stainlesssteel bridge. However, over the whole life cycle thestainless steel bridge appears to be having lower cost.

• Based on assumptions:• Cost of capital = 9.0%; Inflation rate = 3.5%; Real

interest rate = 5.3%

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interest rate 5.3%• Expected life cycle duration = 80 years• Downtime per maintenance event = 120 days; Value of

lost production = $5000/day

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Costs Stainless steel Carbon steel

Material 88,646 31,420

Fabrication 0 0

Other installation 15,611,354 15,611,354

Total initial costs 15,700,000 15,642,774

Maintenance 0 0

Replacement 0 76,872

Lost production 0 2,218,524

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Material-related costs 0 0

Total operating costs 0 2,295,396

Total life cycle costs 15,700,000 17,938,170

c. Strategic planning

• The overall goal is to incorporate life-cycleThe overall goal is to incorporate life cycle environmental thinking into corporate decisions in environmental strategic planning, research and development, product/process design, manufacturing, decommissioning and closure/restoration. Life-cycle assessments have also been used in the corporate level to select

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also been used in the corporate level to select material suppliers, to evaluate the environmental concerns associated with their facilities or product lines and core businesses.

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d. Public sector usesEnvironmental labels (called eco-labels) have been developed to increase the public’sbeen developed to increase the public s environmental awareness.

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“Carbon footprint” and Eco-product

38A. Inaba, Carbon footprint Japan (2009)

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• Life cycle assessment has also been used by governments for setting research and development policy, stimulating markets and setting regulations.

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e. Uncertainties in LCA

• Lack of emission data from other sources within the lifecycle (i.e. incineration, landfills).

• Uncertainty on recycling rate of used product.

• Uncertainty on the allocation of emissions for a single product when multiple products are produced in the same process

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produced in the same process.– Gasoline from the oil refinery

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• Equivalency of products for comparison– Paper vs. plastic bags

Uncertainties on product comparison

Paper vs. plastic bags

• Renewable versus non-renewable source– Paper bags vs. plastic bags

• Biodegradable versus non-biodegradable product at the end of their lives.

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– Paper bags vs. plastic bags

Summary

• LCA integrates environmental impacts over the entire life cycle, from “cradle to grave” and has y gapplications in product design, strategic environmental planning, and public policymaking.

• LCA is a useful tool in green product design, development and improvement and in the

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p pdevelopment of clean technologies by identifying the environmental impact “hotspots” associated with a product or a material.

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Recommended reading materials

• Baumann H. and A.-M. Tillman, “The Hitch-hiker’s Guide to LCA”, Studentlitteratur, Lund, 2004.

• Sample applications of LCA for product, process, corporate and t li d l tgovernment policy development

http://www.lcacenter.org/library/library.html• Cooper, J.S. “Specifying Functional Units and Reference Flows

for Comparable Alternatives,” International Journal of Life Cycle Assessment, 8, 337-349 (2003).

• Jiménez-González, C., S. Kim, M.R. Overcash (2000) “Methodology for Developing Gate-to-Gate Life Cycle Inventory

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gy p g y yInformation,” International Journal of Life Cycle Assessment, 5(3) 153-159

• Heijungs, R., R. Kleijn (2001) “Numerical approaches towards life cycle interpretation: five examples,” International Journal of Life Cycle Assessment, 6(3).

LCA Resources

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LCI databases• Swiss National LCI Database EcoInvent

http://www.ecoinvent.ch/• United States Database Project

http://www.nrel.gov/lci/• Canadian Raw Materials Database

http://crmd.uwaterloo.ca/• The European Union’s European Reference Life Cycle Data System ELCD

http://lca.jrc.ec.europa.eu/lcainfohub/datasetCategories.vm• LCA-National Project in Japan

http://lcacenter.org/InLCA-LCM03/Narita-abstract.pdf• Australian LCA Network

http://simapro.rmit.edu.au/lca/datadownloads.html and http://auslcanet rmit edu au/datapage html

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http://auslcanet.rmit.edu.au/datapage.html• LCA Food Database- Denmark

http://www.lcafood.dk/lcamodel.htm• Swedish National LCA database http://publicdb.imi.chalmers.se/CommDB/• Korea National LCI Database

http://www.kncpc.re.kr/eng/topics/Lci.asp

LCIA Impact assessment tools• USES-LCA 2.0

http://www.ru.nl/environmentalscience/research/life_cycle/multimedia_toxic/

• IMPACT 2002+http://www.sph.umich.edu/riskcenter/jolliet/impact2002+.htm

• Eco-indicator 1999http://www.pre.nl/eco-indicator99/eco-i di t 99 i t d ti ht

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indicator_99_introduction.htm• TRACI

http://www.epa.gov/nrmrl/std/sab/traci/• ReCiPe:

http://www.lcia-recipe.net/

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Comprehensive LCA software

• SimaPro LCA software

http://www.pre.nl/simapro/

• GaBi LCA software

http://www.gabi-software.com/

• TEAM LCA software

https://www.ecobilan.com/

• Economic Input Output LCA assessment:

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• Economic Input-Output LCA assessment:

http://www.eiolca.net/

Other LCA software: Umberto, LCAiT, KCL-ECO

Specialty LCA software

• GREET (Transportation and fuel cycle)htt // t t ti l / d lihttp://www.transportation.anl.gov/modeling_simulation/GREET/index.html

• GHGenius (Transportation, energy)http://www.ghgenius.ca/

• BEES (Green Building Material Selection)

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BEES (Green Building Material Selection)http://www.bfrl.nist.gov/oae/software/bees/

• RETScreen (Energy system analysis)http://www.retscreen.net/ang/home.php