Environmental Life Cycle Assessment An LCA Introduction and an investigation of Biodiesel LCAs Joyce Smith Cooper Mechanical Engineering University of

Environmental Life Cycle Assessment

An LCA Introduction and an investigation of Biodiesel LCAsJoyce Smith Cooper Mechanical EngineeringUniversity of Washington

[email protected]

LCA and Biodiesel

Materialprocessing

Product manufacturing

Product use, maintenance,

upgrade

recovery

disposal

Other life cycles

Assessment Questions:Why? What? Who? Where? How? When?

With what environmental implications?At what cost?

What opportunities exist for partnerships, elimination of toxics, material recovery, …..?

Materialextraction

Defining the Product Life Cycle

Process

MaterialsMaterialsEnergyEnergy

ProductsProducts

ByproductsByproductsWastesWastes

LCA and Biodiesel

A coffee maker’s life cycle

From Pré Consultants, "The Eco-indicator99: A damage oriented method for Life Cycle Impact Assessment, Manual for Designers," http://www.pre.nl/eco-indicator99/index.html

LCA and Biodiesel

Life Cycle AssessmentLCA is a technique technique for assessing the environmental

aspects and potential impacts associated with a product by: compiling an inventory of relevant inputs and outputs of a product system evaluating the potential environmental impacts associated with those

inputs and outputs interpreting the results of the inventory and impact analyses in relation to

the objective of the study.

Goal and Goal and Scope Scope

Definition Definition

Inventory Inventory AssessmentAssessment

InterpretationInterpretation

Impact Impact AssessmentAssessment

Direct Direct ApplicationsApplications

•Product Product development and development and improvementimprovement•Strategic Strategic planningplanning•Public policy Public policy makingmaking•MarketingMarketing

From ISO14040-1997, Environmental management-- Life cycle assessment-- Principles and framework

LCA and Biodiesel

Goal and Scope of the study

• The goal of a LCA describes the intended application (what is being

assessed?), the reasons for carrying out the study, the intended audience (to whom the results of

the study are intended to be communicated)

• The scope of the LCA considersSystem function Included materials and processesType of impact assessment

From ISO14040-1997, Environmental management-- Life cycle assessment-- Principles and framework

LCA and Biodiesel

Different ways to provide the same function

• Hold coffeePlastic cup, polystyrene cup, ceramic cup,

china cup, thermos, …

• Maintain a tidy haircutPlastic comb, metal comb, razor …

• Mowing your lawnPower mower, reel mower, a goat …

• Protecting a surface from corrosionPainting, anodizing, make from plastic ….

From Wenzel, H., M. Hauschild, L. Alting, 2000, Environmental Assessment of Products: volume 1: Methodology, tools, and case studies in product development, Chapman Hall Publishers, New York.

LCA and Biodiesel

Functional Unit

• ISO14040-1997: “a measure of the performance of the functional outputs of the product system”

• Includes:A magnitude A durationA level of quality

LCA and Biodiesel

System Boundaries

• ISO14040-1997: What materials/ equipment will be included

How will this be determined

What phases of the life cycle will be included

• The realityoften by material weight (% of product)facilities, equipment, and infrastructure are

often neglected

LCA and Biodiesel

The Life Cycle Inventory

• Create a process flow diagram/ mass balance for the life cycle.

• IdentifyThe product flows between unit

processesMaterial and energy use and waste that

comes from or goes to the environment

LCA and Biodiesel

The Unit Process

Unit Process

OutputsProductCo-Products= open loop reuse/ recycleWaste (fugitive or to treatment: air, water, solid)

InputsRaw or

Intermediate Materials

Energy

For each unit process, identify inputs, outputs, and recovery as follows:

Closed Loop Reuse/ Recycle

LCA and Biodiesel

Process Data Sources

• Measurements• LCI databases: USDatabase Project, Boustead,

SimaPro, GaBi, DEAM, BUWAL, APME (plastics data)• Literature data:

LCA reports Engineering References: Encyclopedia of Chemical

Technology, Kirk-Othmer, Ulman, etc. Journal and conference papers National laboratory research reports Emission factors (AP-42, etc.) EPA sector notebooks Computation/ Parametric Models (for example, GREET)

Explanations Name Category SubCategoryInfrastructure

ProcessUnits

Gasoline Equipment Combustion

InfrastructureProcess

(blue shading indicates no input required) no

Unit gal

Inputs from Technosphere

Gasoline no gal 1.00E+03

Barge no ton-miles 7.37E+01Combination truck no ton-miles 1.36E+01Pipeline no ton-miles 1.07E+02Rail no ton-miles 8.70E+00

Inputs from Nature

Outputs to Nature1,3-Butadiene air

lb 4.89E-03

Acectaldehyde air lb 9.59E-02Acrolein air lb 1.16E-02Benzene air lb 1.17E-01Carbon dioxide (fossil) air lb 1.74E+04Carbon monoxide air lb 1.13E+03Formaldehyde air lb 1.48E-01Methane air lb 7.68E+00Nitrogen oxide air lb 5.09E-01NOx (unspecified) air lb 2.79E+02PAH air lb 2.10E-02Particulates (PM10) air lb 2.21E+00Propylene air lb 3.23E-01Toluene air lb 5.11E-02SOx (unspecified) air lb 4.18E+00VOC (unspecified) air lb 2.37E+01Xylenes air lb 3.56E-02

Product / co-product outputs

“Gasoline combustion in industrial equipment”Data from the US Database Project at www.nrel.gov/lci/

user name of [email protected] and a password of lci

http://www.nrel.gov/lci/



“Electricity Production”Data from the US Database Project at www.nrel.gov/lci/

user name of [email protected] and a password of lci

Explanations Name Category SubCategoryInfrastructure

ProcessUnits

Electricity Generation in the U.S.

InfrastructureProcess

(blue shading indicates no input required) no

Unit kWh

Inputs from Technosphere

Bituminous/Subbituminous coal no

lb5.30E-01

Lignite coal no lb 4.90E-02

Residual fuel oil no gal 2.20E-03

Natural gas no ft3 1.82E+00

Nuclear fuel (uranium dioxide) no

lb1.40E-06

Hydroelectric energyno

MJ2.79E-01

Biomass/Wood no MJ 1.73E-01

Wind no MJ 5.76E-03

Solar (photovoltaic)no

MJ6.54E-04

Geothermal no MJ 4.37E-02

Other fossil no MJ 7.26E-02

Inputs from Nature

Outputs to Nature

Product / co-product outputs

Electricity Generation in the U.S.

kWh1




LCA and Biodiesel

Impact Assessment

• Impact assessment looks at how inventory flows (cause) contribute to impacts (effect)

• Impact assessment can include Classification

inventory flows are placed in impact categories Characterization

the contribution of each inventory flow is estimated for each impact of interest

Normalization the contribution of the product to each impact at the

global, national, regional, or local level is assessed Valuation/ Weighting

subjective preferences are used to prioritize impact categories and impacts

LCA and Biodiesel

Impact Assessment

• ClassificationInventory materials are categorized as:

Abundant or rare, Hazards, Regulated materials, Recyclable materials, Materials that contribute to global warming,

acidification….

LCA and Biodiesel

Classification by Material Abundance

• Materials can be classified as those in infinite supply: Ar, Br, Ca, Cl, Kr, Mg, N, Na, Ne, O,

Rn, Si, Xe ample supply: Al (Ga), C, Fe, H, K, S, Ti adequate supply: I, Li, P, Rb, Sr potentially limited supply: Co, Cr, Mo(Rh), Hi, Pb

(As, Bi), Pt (Ir, Os, Pb Rh, Ru), Zr (Hf) potentially highly limited supply: Ag, Au, Cu (Se,

Te), He, Hg, Sn, Zn, (Cd, Ge, In, Tl) (lists by-product metals in parentheses after their

reservoir parent)

From Graedel, T., B. Allenby, Design for Environment, Prentice Hall (1996)

LCA and Biodiesel

Classification

• Qualitative process of categorizing inventory flows

Impact Categories in TRACI Abrev Unit of MeasureGlobal Warming GW kg CO2Acidification AC moles H+ equivEutrophication EU kg NOzone Depletion OD kg CFC-11Ecotoxicity EC lbs 2,4-D equivHuman Health Cancer HHC lbs C6H6 equivFossil Fuel FF MJPhotochemical Smog PS g NOX equivWater Use WU galLand Use LU t&e speciesHuman Health Noncancer HHNC lbs C7H7 equivHuman Health Criteria HHCR total DALYs

LCA and Biodiesel

Classification

• Acidification

• Eutrophication

AMMONIAHYDROCHLORIC ACIDHYDROFLUORIC ACIDNITRIC OXIDENITROGEN OXIDES (NOX)SULFUR DIOXIDESULFUR OXIDES (SOX)

AMMONIAAMMONIUMBIOLOGICAL OXYGEN DEMANDCHEMICAL OXYGEN DEMANDNITRATENITRIC OXIDENITROGENNITROGEN OXIDES (NOX)PHOSPHATEPHOSPHORUS

LCA and Biodiesel

Classification: Global Warming

• -(CF2)4CH(OH)-• (CF3)2CFOCH3• (CF3)2CHOCH3• (CF3)2CHOCHF2• (CF3)2CHOH• (CF3)CH2OH• C2F6• CARBON DIOXIDE• CARBON TETRAFLUORIDE• C-C3F6• C-C4F8• CF3 CF2CH2OH• CH3OCH3• FIC-1311• HCFE-235DA2• HFC-125• HFC-134• HFC-134A• HFC-143• HFC-143A• HFC-152• HFC-152A

• HFE-338MCF2• HFE-347MCC3• HFE-347-MCF2• HFE-356MCF3• HFE-356MEC3• HFE-356PCC3• HFE-356PCF2• HFE-356PCF3• HFE-374PCF2• HFE-7100• HFE-7200• HG-01• HG-10• H-GALDEN 1040X• METHANE• NF3• NITROUS OXIDE• PERFLUOROBUTANE• PERFLUOROHEXANE• PERFLUOROPENTANE• PERFLUOROPROPANE• SF5CF3• SF6

• HFC-161• HFC-227EA• HFC-23• HFC-236CB• HFC-236EA• HFC-236FA• HFC-245CA• HFC-245FA• HFC-32• HFC-365MFC• HFC-41• HFC-4310MEE• HFE-125• HFE-134• HFE-143A• HFE-227EA• HFE-236EA2• HFE-236FA• HFE-245CB2• HFE-245FA1• HFE-245FA2• HFE-254CB2• HFE-263FB2• HFE-329MCC2

LCA and Biodiesel

Classification: Carcinogens

• 1,1,1,2-TETRACHLOROETHANE• 1,1,2,2-TETRACHLOROETHANE• 1,1,2-TRICHLOROETHANE• 1,1-DICHLOROETHANE• 1,1-DICHLOROETHYLENE• 1,1-DIMETHYLHYDRAZINE• 1,2,3,4,6,7,8-

HEPTACHLORODIBENZOFURAN• 1,2-DIBROMOETHANE• 1,2-DICHLOROETHANE• 1,2-DICHLOROPROPANE• 1,3-BUTADIENE• 1,3-DICHLOROBENZENE• 1,3-DICHLOROPROPENE• 1,4-DICHLOROBENZENE• 1,4-DIOXANE• 11,12-BENZOFLUORANTHENE• 1-CHLORO-2,3-EPOXYPROPANE• 1-CHLORO-4-NITROBENZENE• 1-NAPHTYL N-METHYLCARBAMATE• 2,3,4,7,8-

PENTACHLORODIBENZOFURAN

• 1,2-DIBROMOETHANE• 1,2-DICHLOROETHANE• 1,2-DICHLOROPROPANE• 1,3-BUTADIENE• 1,3-DICHLOROBENZENE• 1,3-DICHLOROPROPENE• 1,4-DICHLOROBENZENE• 1,4-DIOXANE• 11,12-BENZOFLUORANTHENE• 1-CHLORO-2,3-EPOXYPROPANE• 1-CHLORO-4-NITROBENZENE• 1-NAPHTYL N-METHYLCARBAMATE• 2,3,4,7,8-PENTACHLORODIBENZOFURAN• 2,3,7,8-TCDD• 2,3,7,8-TETRACHLORODIBENZOFURAN• 2,4,6-TRICHLOROPHENOL• 2,4,6-TRINITROTOLUENE• 2,4-D [ACETIC ACID (2,4-DICHLOROPHENOXY)-]• 2,4-DIAMINOTOLUENE• 2,4-DINITROTOLUENE• 2,6-DINITROTOLUENE• etc

LCA and Biodiesel

Characterization

• Characterization is the quantification of the contribution of each inventory flow to each impact of interest

• Whereas inventory analysis can be seen as a model which includes all types of complications (cut-off, multifunctionality, etc.) characterization uses the results of complicated models:Fate and transportExposure assessmentDose-responseEtc.

LCA and Biodiesel

Characterization

• Computational structure

where hi= the contribution of the product system to impact iqij= the equivalency (or characterization) factor for

intervention j for impact igj= components of the inventory vector for

intervention j (remember g=Bs)

∑=j

jiji gqh

LCA and Biodiesel

Global Warming Potentials as Equivalency Factors

• Process X emits 5 kg methane and 4 kg nitrous oxide gCH4 = 5 kg, gN2O = 4 kg

The equivalency factors are the 100-year Global Warming Potentials (GWPs):

qglobal warming- CH4 = GWPCH4 = 21 g CO2/ g CH4

qglobal warming- N2O = GWPN2O = 310 g CO2/ g N2O THEREFORE the potential contribution to global warming for

methane is qglobal warming- CH4 x gCH4 = 5,000 g x 21 g CO2/ g CH4=105,000

g CO2

AND the total contribution of Process X to global warming is: hglobal warming = (105,000 + 1,240,000) g CO2 = 1,345 kg CO2

LCA and Biodiesel

Impact Assessment

• Characterization Inventory materials are weighted by their

contribution to different impacts

• NormalizationCharacterization results are compared to

important levels of impacts (at the national level, for the technology being replaced, etc.)

• Valuation Impacts are weighted by their value to

decision makers

LCA and Biodiesel

Biodiesel LCAs

• Biodiesel is a renewable diesel fuel substitute. can be made from a variety of natural oils and fats.

Biodiesel is made by chemically combining any natural oil or fat with an alcohol such as methanol or ethanol. Methanol has been the most commonly used alcohol in the commercial production of biodiesel.

• In Europe, biodiesel is widely available in both its neat form (100% biodiesel, also known as B100) and in blends with petroleum diesel. European biodiesel is made predominantly from rapeseed oil (a cousin of canola oil).

• In the United States, initial interest in producing and using biodiesel has focused on the use of soybean oil as the primary feedstock mainly because the United States is the largest producer of soybean oil in the world.

From Sheehan, et al. (1998) “Life Cycle Inventory of Biodiesel and Petroleum Diesel for Use in an Urban Bus,” NREL/SR-580-24089 UC Category 1503

LCA and Biodiesel

Why LCA of Biodiesel?

• Proponents of biodiesel as a substitute for diesel fuel (in blends or in its neat form) can point to a number of potential advantages for biodiesel that could support a number of strategies for addressing national issues:Reducing dependence on foreign petroleum…Leveraging limited supplies of fossil fuels….Mitigating greenhouse gas emissions….Reducing Air Pollution and Related Public

Health Risks….Benefiting our domestic economy….


LCA and Biodiesel

Biodiesel Synthesis Pathways

From Holbein, et al. (2004) “Canadian Biodiesel Initiative: Aligning Research Needs and Priorities With the Emerging Industry,” Prepared for Natural Resources Canada

LCA and Biodiesel

Biodiesel LCAs

• Several biodiesel LCAs have been performed (US, Canada, Germany…)

• The foremost US study was a LCI funded by the USDOE and US Department of Agriculture:

Sheehan, et al. (1998) “Life

Cycle Inventory of Biodiesel

and Petroleum Diesel for Use

in an Urban Bus,”

at http://www.nrel.gov/docs/legosti/fy98/24089.pdf

LCA and Biodiesel

The US Biodiesel LCA

• Reductions in Petroleum and Fossil Energy Consumption Substituting 100% biodiesel (B100) for petroleum diesel in buses

reduces the life cycle consumption of petroleum by 95%. This benefit is proportionate with the blend level of biodiesel used.

When a 20% blend of biodiesel and petroleum diesel (B20) is used as a substitute for petroleum diesel in urban buses, the life cycle consumption of petroleum drops 19%.

It was found that the production processes for biodiesel and petroleum diesel are almost identical in their efficiency of converting a raw energy source (in this case, petroleum and soybean oil) into a fuel product. The difference between these two fuels is in the ability of biodiesel to utilize a renewable energy source.

Biodiesel yields 3.2 units of fuel product energy for every unit of fossil energy consumed in its life cycle. The production of B20 yields 0.98 units of fuel product energy for every unit of fossil energy consumed.

By contrast, petroleum diesel’s life cycle yields only 0.83 units of fuel product energy per unit of fossil energy consumed. Such measures confirm the “renewable” nature of biodiesel.


LCA and Biodiesel


• Reductions in CO2 Emissions Given the low demand for fossil energy associated with

biodiesel, it is not surprising that biodiesel’s life cycle emissions of CO2 are substantially lower than those of petroleum diesel.

Biodiesel reduces net emissions of CO2 by 78.45% compared to petroleum diesel. For B20, CO2 emissions from urban buses drop 15.66%.

In addition, biodiesel provides modest reductions in total methane emissions, compared to petroleum diesel. Methane is another, even more potent, greenhouse gas. Thus, use of biodiesel to displace petroleum diesel in urban buses is an extremely effective strategy for reducing CO2 emissions.


LCA and Biodiesel


• Changes in Air Pollutant EmissionsThe effect of biodiesel on air quality is more

complex. Biodiesel, as it is available today, offers substantial improvements in some air pollutants, while it leads to increases in others.

The use of B100 in urban buses results in substantial reductions in life cycle emissions of total particulate matter, carbon monoxide and sulfur oxides (32%, 35% and 8% reductions, respectively, relative to petroleum diesel’s life cycle).


LCA and Biodiesel


• Particulates, Carbon Monoxide and Sulfur Oxides... are targeted by EPA because of the important role they play in

public health risks, especially in urban areas where the acute effects of these pollutants may be greater.

Given the concern over urban air quality, it is important to note that most of these reductions occur because of lower emissions at the tailpipe. For buses operating in urban areas, this translates to an even greater potential benefit:

Tailpipe emissions of particulates less than 10 microns in size are 68% lower for buses run on biodiesel (compared to petroleum diesel). In addition, tailpipe emissions of carbon monoxide are 46% lower for buses run on biodiesel (compared to petroleum diesel). Biodiesel completely eliminates emissions of sulfur oxides at the tailpipe.

The reductions in air emissions reported here are proportional to the amount of biodiesel present in the fuel. Thus, for B20, users can expect to see 20% of the reductions reported for biodiesel used in its neat form (B100).


LCA and Biodiesel


• Increased Emissions of Nitrogen Oxides (NOx)…NOx is one of three pollutants implicated in the

formation of ground level ozone and smog in urban areas (NOx, CO and hydrocarbons).

The use of B100 in urban buses increases life cycle emissions of NOx by 13.35%. Blending biodiesel with petroleum proportionately lowers NOx emission. B20 exhibits a 2.67% increase in life cycle emissions of NOx.

Most of this increase is directly attributable to increases in tailpipe emissions of NOx. B100, for example, increases tailpipe levels of NOx by 8.89%.


LCA and Biodiesel


• Hydrocarbons—higher on a life cycle basis, but lower at the tailpipe… The increase in hydrocarbon emissions is due to release

of hexane in the processing of soybeans and volatilization of agrochemicals applied on the farm.

Total life cycle emissions of hydrocarbons are 35% higher for B100, compared to petroleum diesel. However, emissions of hydrocarbons at the tailpipe are actually 37% lower.

These results point out opportunities for improving the life cycle of biodiesel. Future biodiesel research should focus on ways of reducing hexane releases from today’s current levels in soybean crushing plants.

Improvements in use of agrochemicals on the farm would have similarly beneficial effects.


LCA and Biodiesel

The UK Biodiesel LCA: with Impact Assessment

• A UK-based LCA included impact assessment considering two types of biodiesel production. One where the biodiesel is produced using more conventional means and one where it is produced : Using low nitrogen methods of cultivation With the rapeseed straw as an alternative heating fuel for

the drying, solvent extraction, refining and esterification process.

With biodiesel as the fuel for agricultural machinery and transportation.

• Among the 2, conventional production is considered a conservative representation as follows.

From Mortimer, et al. (2003) “EVALUATION OF THE COMPARATIVE ENERGY, GLOBAL WARMING AND SOCIO-ECONOMIC COSTS AND BENEFITS OF BIODIESEL,” Prepared for the Department for Environment, Food and Rural Affairs

LCA and Biodiesel

A UK Biodiesel LCIA: Carbon Dioxide and GHG Emissions

• Biodiesel is described as ‘carbon neutral’ such that any CO2 emissions associated with it comes from a source outside that of combustion of the fuel.

• In fact there are many sources of CO2 associated with biodiesel production. Most of the emissions come from the esterification process, the production of fertilizer and the extraction of the oil from the seed. These CO2 emissions are not always produced directly from the

process but taken from the energy requirement. What this means is that the energy a process uses has an associated emission. For example electricity used in the esterification process may well come from a coal power plant, so the amount of electricity used can be related to the amount of CO2 released from the plant.

• It was found that for every ton of biodiesel produced 916 ± 52 kg CO2 was released into the atmosphere.

• This dominates the greenhouse gas emissions: for each ton of biodiesel produced the equivalent of 1,516 ± 88 kg of CO2 are released.

From http://www.esru.strath.ac.uk/EandE/Web_sites/02-03/biofuels/why_lca.htm andMortimer, et al. (2003) “EVALUATION OF THE COMPARATIVE ENERGY, GLOBAL WARMING AND SOCIO-ECONOMIC COSTS AND BENEFITS OF BIODIESEL,” Prepared for the Department for Environment, Food and Rural Affairs

LCA and Biodiesel

A UK Biodiesel LCIA: Carbon Dioxide Emissions


LCA and Biodiesel

• For every ton of biodiesel produced 16,269 ± 896 MJ of energy is required.


• By quantifying the amount of energy required to produce biodiesel it is possible not only to see what processes require the most energy but also to establish an energy balance over the life cycle. I.e. the energy you get out against the energy you put in.

LCA and Biodiesel

A UK Biodiesel LCIA: What does it mean?

• Not surprisingly the largest energy demands match up with the CO2 emissions.

• A ton of biodiesel will contain around 40,800MJ of energy. Energy Balance = Energy OUT / Energy IN = 40,800 / 16.269 = 2.5

• For these number to mean anything however there has to be something against which to compare them. In the case of biodiesel this would be the LCA of fossil diesel. From http://www.esru.strath.ac.uk/EandE/Web_sites/02-03/biofuels/why_lca.htm and

Mortimer, et al. (2003) “EVALUATION OF THE COMPARATIVE ENERGY, GLOBAL WARMING AND SOCIO-ECONOMIC COSTS AND BENEFITS OF BIODIESEL,” Prepared for the Department for Environment, Food and Rural Affairs

LCA and Biodiesel

A UK Biodiesel LCIA: Bio- vs. Fossil- Diesel

• CO2 Emissions For each MJ of biodiesel produced 0.025Kg of CO2 is

released. For each MJ of fossil diesel produced 0.087Kg of CO2 is

released.

• GHG Emissions For each MJ of biodiesel produced 0.041Kg of GHG CO2

equivalent is released. For each MJ of fossil diesel produced 0.095Kg of GHG CO2

equivalent is released.

• Energy Requirements For each MJ of biodiesel produced 0.45 MJ is required. For each MJ of fossil diesel produced 1.26 MJ is required.


Documents

Environmental Life Cycle Assessment An LCA Introduction and an investigation of Biodiesel LCAs Joyce Smith Cooper Mechanical Engineering University of