Presentation on theme: "Environmental Life Cycle Assessment"— Presentation transcript:
1 Environmental Life Cycle Assessment Firoz Jameel, Jesse Daystar and Richard A. Venditti*Department of Wood and Paper ScienceNorth Carolina State UniversityRaleigh, NC*Corresponding author:(919)
2 Introduction Learning Objectives of this section: Be able to define a LCATo understand an LCA’s importanceTo identify important aspects of an LCAThis is the introduction
3 Sustainability?How do we supply societies needs without harming the environment or future generations’ ability to meet their needs?We have many options to meet our demands.How to choose the “best” option?Life cycle assessment helps to inform our choices.
4 What is a Life Cycle Assessment ? Life Cycle Assessment (LCA) is a tool to assess the potential environmental impacts of products, systems, or services at all stages in their life cycle [ISO 14001:2004].Types of LCACradle to Gate: raw materials to finished good (no use or end life considerations)Cradle to Grave: Considers everything from harvesting materials to the disposal of the finished goodsLife Cycle Assessment (LCA) is a tool to assess the potential environmental impacts of products systems or services at all stages in their life cycle. The chart above depicts the typical stages of the life cycle of a product. The five important ones illustrated are raw materials (supplier), transport, manufacturing, use, and disposal. Packaging Is generally combined with manufacturing.
5 Example LCA Process Production Use Disposal Recycle Raw Materials TransportationUseDisposalRecycleEnergyWasteEmissions to air and waterRecycled MaterialsRaw MaterialsThe unit processes for each LCA can vary. Often times there will be transportation between each unit process but this is not always the case.
6 Why is an LCA Important? Helps ensure compliance with government regulationsHelps decrease the environmental impact of a given productIdentifies ways to improve sustainabilityIdentifies ways to “green” all aspects of product’s lifeCan reshape company strategyCan help marketingCan reshape company imageDevelop product advantage of competitionAn LCA is also important because it helps ensure compliance with government regulations. If the government mandates that a certain type of emission must be reduced, an LCA can help identify certain ways to reduce that type of emission and ensure compliance with that regulation.Furthermore, it can improve the environmental impact of a certain product by improving its sustainability or by “greening” different aspects of a products life. Improving the sustainability includes finding more renewable sources for basic materials and reducing a products dependence on non-renewable resources. Greening different aspects of a product’s life means figuring out ways to improve the environmental impact of the product at all stages of its life, including manufacturing, usage, and disposing it.An LCA can identify ways for the product to become more environmentally friendly. It can help elicit changes to the manufacturing process and the materials used so that the product is much friendlier to the environment. LCAs can also reshape corporate strategies. It can alter a company’s mindset and help it pursue more environmentally friendly goals.Finally, an LCA can help with marketing. It can be used to justify/support a claim that a product is “green,” an issue that most people believe is very important in purchasing a new product. This can also improve a company’s image.6
7 Important Aspects of Life Cycle Assessment InterpretationImpact AssessmentInventory AnalysisGoal and Scope DefinitionThe following are the normal steps for a LCA.Definitions:Goal and Scope definition: Identifies the intended purpose of the LCA and determines what items shall be considered.Inventory analysis: identifies the major steps of the life cycle and analyzes the associated requirements (materials needed, energy required, etc) and the wastes produced at each step.Impact assessment: An impact analysis “aims to examine the product system from an environmental perspective using impact categories and categoryindicators connected with the [inventory analysis’] results. The [impact assessment] phase also provides information for the life cycle interpretationphase.” (ISO 14042)Interpretation: “The objectives of life cycle interpretation are to analyze results, reach conclusions, explain limitations and providerecommendations based on the findings of the preceding phases of the LCA or LCI study and to report the resultsof the life cycle interpretation in a transparent manner.” (ISO 14043)
8 Goal and Scope Definition Learning Objectives of this section:To understand how to properly define the goals of an LCATo understand how to establish the boundaries of an LCAThe purpose of this section is to explain how to establish the goals and the scope of an LCA
9 Defining Goals Should state the intent of the study Intended applicationIntended useIntended audienceShould also include reason for the studyFirst, the analyst needs to define the goals of the LCA. This means stating the intent of the study, including the intended application (what aspect of the LCA it will analyze), the intended use (what will be done with the results), and the intended audience. Also, a reason for conducting the study should be provided.Defining the goals and scope thoroughly is extremely important to the an LCA. This step is unique to each LCA and will determine the processes and steps that will be considered.
10 Defining Scope Define functional unit of product Help establish system boundaries for the LCADetermine data collection methodsWhen defining scope, the analyst needs to keep the following things in mind. The analyst needs to specify the intended purpose of the LCA and what key issues it will address. The analyst also needs to define boundaries and determine what needs to be included in the LCA. This is because it helps restrict the size of the LCA.Depending on the goals, the analyst should decide where boundaries need to be drawn and what should and shouldn’t be included. Boundaries also need to be drawn within the LCA. This helps determine what input/output goes where. general, inputs and outputs that are deemed to be energy intensive, environmentally intensive, or require large amounts of it.Finally, the analyst should determine proper data collection methods. Data can come from a variety of places. The two main types of data are primary data (data taken by the analyst) and secondary data (data taken from published or other sources). Either way, the data should be precise, complete, consistent, and reproducible.
11 Goal and Scope Definition: Your Turn Exercise: Define the goal and scope of an LCA designed to study the life cycle of a peanut butter and jelly sandwichYou’ve been hired by a large peanut butter conglomerate to study the life cycle of a PB and J sandwich. Your first goal is to define your goals and the scope of the study.Goals & IntentIntended Application: To inform the Wake County Public School food purchasers of the environmental impact of a PB&JIntended Use: To determine the global environmental impacts of serving a PB&J for Wake County Public SchoolsIntended Audience: Wake County Public School food systemScopeSystem boundaries:Include: impact from the creation of the raw ingredients of the peanut butter, jelly, bread and containers for transportation.Include: energy of production of bread, peanut butter, jelly and the packaging.Include: impact from transportation of ingredients, packaging, productAnalysis ends with the food being ingested by a person.
12 Important Aspects of Life Cycle Assessment InterpretationImpact AssessmentInventory AnalysisGoal and Scope DefinitionThe following are the normal steps for a LCA.Definitions:Inventory analysis: identifies the major steps of the life cycle and analyzes the associated requirements (materials needed, energy required, etc) and the wastes produced at each step.12
13 Inventory Analysis Learning Objectives of this section: To understand what needs to be included in an inventory analysisTo understand the steps and processes included in an inventory analysisInventory analysis: identifies the major steps of the life cycle and analyzes the associated requirements (materials needed, energy required, etc) and the wastes produced at each step.
14 Inventory Analysis: What Needs to be Included? All relevant stages of the life of a productRaw Materials/Energy NeedsManufacturingTransportation, Storage & DistributionUse, reuse, and maintenanceRecycle & Waste ManagementProductionTransportationUseDisposalRecycleEnergyWasteEmissions to air and waterRecycled MaterialsRaw MaterialsAn LCA should analyze the following five aspects of the life of a product- Raw Materials, Manufacturing, Distribution, Use, and Disposal.Use example: Refrigerator that consumes electricity everyday has a large use impact.
15 Inventory Analysis: Setup In an LCA, it is necessary to standardize all units of measureFor measuring energy useUse mega joules (MJ) to measure potential energy from non-renewable sourcesUse kilowatt hours (kW-h) to measure electrical energyFor measuring waste materials and emissionsUse tons to measure airborne emissions and solid wasteUse gallons or liters to measure waterborne emissionsCreate a standard basis for comparisonExample: per product piece, or per kg of productEstablish rigid boundaries for the Inventory Analysis
16 Inventory Analysis: Raw Materials & Energy Needs Two types of Raw MaterialsPrimary- first use materialSecondary- second use material (recycled)Analyze energy requirementsEnergy required to harvest the raw materialsEnergy required to convert the raw materials to the finished productLook at materials associated with maintaining the raw materialsDefine and quantify emissions and wastes associated with the production of the raw materialsIf the materials are not recycled or reused (not post-consumer), this is considered a primary raw material. For primary raw materials, the impact of the acquisition and refining of it needs to be taken into account. Usually, industry wide data will suffice.If the material does come from post-consumer sources, this is considered a secondary raw material. The impact of the process of converting this material needs to be taken into account. What is generally included in this step of analyzing the raw materials is a look at the products used to maintain the raw material (fertilizer, pesticides, etc), infrastructure used to acquire it (machinery and roads), and the outputs associated with the production of the materials.
17 Inventory Analysis: Manufacturing Manufacturing should take into account the followingToolsMolds, machinery, etc.ProcessesWaste MaterialPackagingAll emissions producedEnergy usedWhen conducting the inventory analysis of the manufacturing process, it is important to take the following areas into account: tools, processes, waste material, and packaging. For tools, acquire data about the manufacture and upkeep of these tools as this will help you determine how eco-friendly these tools are. Also take into account the amount of energy it takes to operate these tools. For processes, it is important to analyze the energy consumed in each process and include all byproducts (emissions, waste, etc).Waste material, such as scrap material, should be taken into account. The process of disposing or reusing these materials should be analyzed. With regards to packaging, analyze the materials used by looking at the source of the material and determining if it is possible to reuse these materials.The analyst also needs into account all the emissions that are produced during the manufacturing process. This includes all waterborne and airborne emissions. Also, the amount of energy used in the entire manufacturing process needs to be accounted for. Included should also be the source of the energy. In general, energy is either primary or secondary energy. Primary energy is energy that comes from outside of the manufacturing process (like from an electrical grid). Secondary energy is energy that is produced by the manufacturing process and is used to power part of the process. An example of this is the incineration of waste products to create energy. Also, energy can either come from renewable or non-renewable sources. The analyst needs to determine where this energy is coming from.
18 Inventory Analysis: Transportation, Storage and Distribution Equipment used to move goodsAirplanes, trucks, trains, etcDistanceStorage and DistributionWarehousesWholesalersRetailersFor transportation, look at the amount of energy required to ship the goods from one location to another and all emissions produced. With regards to distribution, figure out how most of the consumers will acquire the product. Will the product first be shipped from a warehouse to a store, then driven by the consumer back home? Determine how the product will reach its end destination and estimate how much energy will be produced and determine which emissions will likely be produced.
19 Inventory Analysis: Use, Reuse and Maintenance Inventory or materials and energy required to fully utilize the productUseEnergy required for normal useEmissions from normal use of the productReuseReusing product for the intended purposeReusing the product in a different mannerMaintenanceReplacement partsMaintenance fluidsOils, grease, polish, paint, etcgasolineCO2, H2Omotor oil, oil & air filter, hoses, tires, etc.spent motor oil, oil & air filter, hoses, tires, etc.spare parts for newer carsTo analyze use, determine how much energy is required for the everyday use of the product and all potential emissions. The same process is used to analyze the product if it is reused for its intended purpose. If not used for its intended purpose, it becomes much more difficult to assess its impact on the environment. For maintenance, look at the impact of producing replacement parts, disposal of obsolete parts and the impact of producing and disposing maintenance fluids.
20 Inventory Analysis: Recycle and Waste Management Salvage of useful partsProduction of secondary raw materialsWaste ManagementDisposal of non-salvageable productLandfills, hazardous waste dumps, etcIncinerationCompostingTo determine the impact of recycling, it is important for the analyst to determine which pieces of the product can be reused and the environmental impact of the process of converting this material into its final product.For waste management, it is important to look at all the different ways the product can be disposed of. If it is biodegradable, it is likely that it can be composted or incinerated. In the case of incineration, it is important to look at potential emissions from burning the product. If the product is not composted/incinerated, it is placed in a landfill. It is necessary to look at how much space it takes in the landfill and the emissions produced by the product as it decomposes. Some of these emissions, like methane, can be harmful.
21 Inventory Analysis: Types of Pollution Three main types of pollutionAirborne emissionsCarbon dioxide, sulfur dioxide, etcWaterborne emissionsWastewater, untreated chemicals, etcSolid wasteScrap materials, process waste, etcThroughout the inventory analysis, it is important for the analyst to consider many of the byproducts that can be deemed pollution. Three main types are airborne emissions, waterborne emissions, and solid waste. Where each type of emission is produced should be included in the LCA. Airborne emissions are pollution that is released into the atmosphere. This type of pollution spreads very quickly and can lead to long term problems. It if very hard to remove airborne pollutants and preventive steps should be taken to reduce their presence in the atmosphere.
22 Inventory Analysis: ISO Standard Overall steps for LCA are defined in ISO 14044Steps for conducting an inventory analysis are explained in ISO 14041Steps involvedPreparing for data collectionData collectionValidation of dataRelating data to unit processRelating data to functional unit and data aggregationRefining system boundariesProper protocol for conducting an inventory analysis is explained in ISO The six main steps are listed above.The first is preparing for data collection. This means ensuring that the data is going to be standardized to ensure a consistent understanding. This includes describing each individual process that data will be collected for and describing how the data will be collected.Second, the data has to be collected. Data is either collected from primary or secondary sources. For primary data, qualitative and quantitative descriptions of each unit process along with inputs and outputs should be included to help with this. For secondary data, information about where it was published should be included. Afterwards, the data must be validated and by checking for anomalies in the data. This can be accomplished by conducting mass balances, energy balances, and comparative analyses of the emissions factors. At this point, data anomalies should be replaced from another acceptable source or measured again.Next, the data must be related to the unit process. This means that the data needs to line up with the processes. A standard of measure needs to be created (e.g. 1 MJ per 1 Kg product produced to measure energy requirements).Following this, the data needs to be related to the functional unit and data aggregation. This means standardizing the data so that it can fit and can be easily compared within the entire system.Finally, all the system boundaries should be redefined if necessary. This means eliminating certain areas because it is revealed that they are no longer pertinent or including new unit processes that may be important.
23 Inventory Analysis: Example Example product: copy paperRaw MaterialsWood, water, various chemicals, energyChemical and Energy RecoveryManufacturingMachinery, processes, packaging materialTransportation and DistributionStorage of paper in warehouses, selling of it via wholesalers/retailersUseProducts associated with the use of copy paperDisposalWaste products, Recycling, landfillingEnergy recoveryIn this slide, we conduct a mock inventory analysis for copy paper. In the raw materials phase, the analyst needs to determine what materials are necessary for the production of paper. Such materials include wood, water, chemicals such as bleaches and acids, energy, etc.The analyst must also look at where the energy for conducting the manufacturing process comes from. In most paper mills, the energy is self supplied fusing energy recovering techniques as they burn used chemicals. In the manufacturing phase, the analyst needs to look at the environmental impact of the machinery and processes of producing paper. Examples of machines include Chippers, Debarkers, Digesters, Bleaching Towers, Paper machines, etc. Examples of processes include bleaching the pulp, screening the pulp to make the sheets, packaging it, etc. In this step, the analyst needs to account for all emissions and waste produced.In the next step, the transportation and distribution step, we need to look at the environmental impact of transporting the copy paper. It can be transported by any variety of means (airplane, train, truck, etc) and the impact of this, especially emissions released, needs to be analyzed. For use, the analyst needs to determine what products will be used with the copy paper (toner, the copier, etc) and the environmental impact of using these products with the copy paper.For disposal, the analyst needs to determine the feasibility of recycling the product and the likelihood of doing so. The analyst also needs to analyze the impact of the paper in the landfill, from spatial issues to decomposition. Most of the waste produced in the manufacturing process is incinerated to produce energy.
24 Inventory Analysis: Your Turn Exercise: Conduct an Inventory Analysis of a Peanut Butter and Jelly Sandwich:Example Inventory Analysis:Raw Materials:Peanut butter: peanuts, sugar, oilsJelly: sugar, fruit, coloringBread: flower, butter, preservativesProcess raw materials: water, energyManufacturing:Machinery, processes, packaging material, waste disposalTransportation:transporting raw materials, finished goods to warehouse, goods from warehouse to store, store to consumer end use locationUse:Products associated with use of PB&J, ex. Napkin, knifeProcessesRaw material farmingTransportationRaw material acquisitionProduct ManufacturingUseWaste managementProcess Inputs & OutputsInputsIngredients & materialsEnergyWaterOutputs:EmissionsEffluentsSolid wastesOther releasesProductsCo-products
25 Important Aspects of Life Cycle Assessment InterpretationImpact AssessmentInventory AnalysisGoal and Scope DefinitionThe following are the normal steps for a LCA.Definitions:Impact assessment: An impact analysis “aims to examine the product system from an environmental perspective using impact categories and categoryindicators connected with the [inventory analysis’] results. The [impact assessment] phase also provides information for the life cycle interpretationphase.” (ISO 14042)25
26 Impact Assessment Definition: Impact assessment is the process of identifying the future consequences of a current or proposed action. (cbd.int/impact)Learning Objectives of this section:To understand what needs to be included in an impact assessmentTo identify the usual steps and processes included in an impact assessmentImpact assessment: details the environmental impact of these materials, processes, and equipment. This step is where the analyst should gather corresponding data for each process as well as detail all outputs for the process. Outputs can include intended outputs like the final product, and by products such as airborne emissions, waterborne emissions, and solid waste.
27 Impact Assessment: ISO Standard Overall steps for LCA are defined in ISO 14044Protocol for an impact assessment is explained in ISO 14042Mandatory elements for an impact assessmentSelection of impact categoriesAssignment of inventory analysis resultsCalculation of category indicator results (characterization)Optional elementsCalculation of the magnitude of category indicators (normalization)GroupingWeightingTo conduct the impact assessment, the analyst needs to do at least the mandatory steps. First, the analyst must select the impact categories that will be studied. A general criteria is to create categories that pertain to the end goal of the study, address key environmental issues, and leave no holes in the impact assessment. All categories should be clearly named and the decision to select such a category should be justified.After this, results from the inventory analysis should be assigned to the different impact categories. This should be done to highlight environmental issues with each part of the inventory analysis. These can go into multiple impact categories depending on how the categories are defined and the environmental impact of the item in question.Finally, the analyst must calculate the category indicator results, a step commonly referred to as characterization. This final step aggregates and standardizes the data so that it can be easily compared. This involves selecting characterization factors (particular impact that is being studied) to convert the inventory analysis to similar units of measure.While these are the only mandatory steps of an impact assessment, the following three can help improve it. The first of these three is called normalization. This step transforms data by dividing it by a specific reference value (like a set amount of time or space). An example would be tons of emissions per day or something along those lines. This step is helpful because helps check for inconsistencies and can help explain the significance of the data. The second optional step is grouping. This involves refining the impact categories selected. This can be done either by grouping them together by rank (highest priority to lowest priority) or by sorting the categories by characteristics. The final optional step is weighting. This step essentially determines what impact gets a greater emphasis and is more important. If this step is done, it must be done in a clear and transparent manner.
28 Impact Assessment: What Needs to be Included? All environmental impacts associated with the production, use and disposal of the productEcological Systems DegradationResource DepletionHuman Health & WelfareAdd environmental indices here also.After taking an inventory of the products and the potential emissions, its important to analyze the impact of these products. Three important areas are ecological systems degradation, resource depletion, and human health and welfare.Ecological system : An ecosystem is a natural unit consisting of all plants, animals and micro-organisms (biotic factors) in an area functioning together with all of the non-living physical (abiotic) factors of the environment. (^ Christopherson, RW (1996) Geosystems: An Introduction to Physical Geography. Prentice Hall Inc.Resource depletion: the exhaustion of raw materials within a regionHuman Health & Welfare: the health and welfare of people living in surrounding areas to production facilities or raw material acquisition sites.
29 Impact Assessment: Ecological Systems Degradation Ecological system : An ecosystem is a natural unit consisting of all plants, animals and micro-organisms (biotic factors) in an area functioning together with all of the non-living physical (abiotic) factors of the environment. (Christopherson, 1996)ChemicalToxicityPhysicalHabitat LossBiologicalForeign SpeciesFor ecological systems degradation, its important to look at the potential effects that the emissions released by the product and the potential affect it can have on its surroundings. Most of these chemicals released have some adverse effect or another. They can cause any range of problems from spoiling drinking water to causing acid rain.It is important to look at the toxicity of these chemicals and how potent they can be if mistreated. These chemicals and emissions can cause habitat loss (such as deforestation from acid rain).Furthermore, if parts of your product are imported from abroad, it can lead to the importation of foreign species that can forever alter the surrounding environment.Invasive species-Kudzu
30 Impact Assessment: Ecological Systems Degradation – Risks Assessment FClFreon 11Ecological Response to IndicatorIntensity of Potential EffectTime Scale of RecoverySpatial ScaleTransport MediaThere is no global agreement in weighting risksHole in ozone layer caused by FreonTo help determine these risks, its important to look at the following: how the environment responds to the pollutant, the potential damage of the pollutant, how long it takes to recover from the damage, the extent of the damage, and how the pollutant is spread (airborne, waterborne, etc).
31 Impact Assessment: Resource Depletion Resources are either renewable or non-renewableRenewableHydroelectric energy, biomass products, most crops, etcNon-renewableOil, minerals, metals, etcIdeally want to recycle as many non-renewable based components as possibleThe analyst must determine if a resource is renewable or non-renewable. If a resource is non-renewable, the analyst may want to find ways to reduce the amount of non-renewables in a process or determine more ways of recycling them.Example: Unsustainable forest practices can lead to lack of usable forest land and trees.
32 Impact Assessment: Human Health & Welfare Analyze impact of product on human healthDiseases that could potentially be caused by using the productCigarettes: CancerDiseases that can be caused by wastes produced by the product or the production of itSolid particulates emitted in stack gasses for a coal burning plant: CancerProducts that harm human health can have a negative impact on a company’s imageFinally, it is important to analyze the product’s life cycle’s impact on human health. Hopefully, if all proper precautions are taken, there should be no adverse effects. However, it is important to list potential health problems caused by the product that you are aware of.
33 Environmental Indices IGW – global warmingISF – smog formationIOD – ozone depletionIAR – acid rainIINH – human inhalationIING – ingestion toxicityICINH -human carcinogenic inhalationICING – carcinogenic ingestion toxicityIFT – fish toxicityIXXGlobal Warming- indicates the potential to increase earths insulation layer resulting in higher global temperaturesSmog Formation- Indicates the potential to create smog. NOXs highly impact this indexOzone Depletion- Indicator of the potential for ozone depletion. Such compounds as Freon impact this index greatlyAcid Rain- The potential for the process to make the moisture in the atmosphere acidic. This moisture is then released as rain.Human Inhalation- Indicates the potential for causing respiratory problems in humansIngestion Toxicity- Indicates the potential for harmful ingestion to occurHuman Carcinogenic Inhalation- Indicate the risk associated with inhaling carcinogenic matterCarcinogenic ingestion toxicity- Indicates the risk of ingesting carcinogenic materailsFish Toxicity- indicates the potential for pollutants to affect fish33
34 Impact Assessment: Example Example product: copy paperEcological systems degradationImpact of cutting down treesImpact of discharged chemicals in the water waste on the water qualityResource depletionResource is renewable because it is trees,but it is not rapidly replaceableThe paper is easily recyclable, reducingprimary raw material neededFor energy, mostly self sufficientHuman health and welfareImpact of chemicals used on human healthImpact of stack emissions from chemical and energy recovery on health of population around millOnce again, we shall conduct a mock impact assessment of copy paper. When analyzing the potential degradation of ecological systems, it is important to look at the environmental impact of all steps. Examples of such degradation include the cutting down of trees (leading to deforestation and habitat loss if done irresponsibly), inadvertently releasing chemicals used to treat the product into the water (leading to a polluted water source and once again causing habitat loss), and airborne emissions from the production of the paper (can lead to the release of greenhouse gasses and acid rain).For resource depletion, the analyst needs to take a more in depth look at the actual raw materials. For paper, the primary raw material is of course wood from trees. While trees are a renewable resource, they are slow growing and therefore take a lot of time to replace. Therefore, the analyst should determine whether or not it is feasible to use secondary raw materials and recycle the paper. Fortunately, paper is easily recyclable. With regards to energy, a paper plant can supply a large part of the energy needed through burning waste products in the energy recovery processes.Finally, the analyst should investigate potential health problems related to the use and production of paper. Potential problems can include the effects of accidentally consuming poorly treated chemicals released into the water supply. Also, airborne emissions from the manufacture and energy recovery processes adversely affects human life because of the odor produced and the potentially toxic chemicals released.
35 Impact Assessment: Your Turn Exercise: Conduct the impact assessment for a Peanut Butter and Jelly SandwichExamine:Ecological system degradation1. impact of fertilizer runoff2. deforestation for farm landResource Depletion1. energy resources such as oil or coal2. impact of the soil nutrient depletionHuman Health and Welfare1. health impacts of fertilizers used on humans due to ingestion2 health impacts of air pollutants due to peanut processing and transportation such as CO2
36 Important Aspects of Life Cycle Assessment InterpretationImpact AssessmentInventory AnalysisGoal and Scope DefinitionThe following are the normal steps for a LCA.Interpretation: “The objectives of life cycle interpretation are to analyze results, reach conclusions, explain limitations and providerecommendations based on the findings of the preceding phases of the LCA or LCI study and to report the resultsof the life cycle interpretation in a transparent manner.” (ISO 14043)36
37 Interpretation Learning Objectives of this section: To be able to identify what needs to be included in an interpretationTo understand how this step can be best usedInterpretation: the stage at which the analyst deduces potential ways to make the process more environmentally friendly
38 Interpretation: ISO Standard Overall steps for LCA are defined in ISO 14044Proper protocol for interpretation is explained in ISO 14043Aside from presenting results, the interpretation should conduct these checksCompleteness checkSensitivity checkConsistency checkInclude conclusions and recommendationsThe analyst, aside from presenting results, needs to check the entire LCA by conducting these three checks: a completeness check, a sensitivity check, and a consistency check. The completeness check ensures that all relevant data is present and is not omitted. If certain data is missing and is deemed unnecessary, this should be justified. However, if it is deemed necessary, the preceding steps of the LCA should be revisited.The sensitivity check should assess the reliability of the data and ensure that it has not been affected by uncertainties in other areas. Finally, the consistency check ensures that the LCA adheres the stated goals and scope. After these checks are completed, the analyst should provide their conclusions and recommendations.
39 Interpretation: The Feedback Mechanism Analyze opportunities to reduce or mitigate the environmental impact throughout the whole life cycle of a product, process or activity.Analysis may include both quantitative and qualitative measures of improvementChanges in product designChanges in raw material usageChanges in industrial processesOriginal productAfter Improvement AnalysisThe final stage of the LCA is the improvement analysis. This is where the analyst looks at the previous steps and determines ways to reduce a given product's impact on the environment. This can include changing product design, raw materials, or the industrial process. Changes in product design help effect change in the use by consumer and waste management. The diagram shows the process of manufacturing ethanol. In much of the western world, ethanol is produced using products that can also be used for food. However, due to a shortage of food across the world, manufacturers of ethanol have been forced to find new raw materials. They conducted an LCA and determined in the improvement analysis that they should shift away from corn and move towards other biomass, like trees and grasses.
40 Interpretation: Example Example product: copy paperChanges in product designDetermining potential areas of improvement for the product designLighter weight paper?Lower brightness paper?Changes in raw materialsUsing more secondary materials in place of primary materialsUse alternative chemicalsChanges in industrial processChanging from Acid to Alkaline papermakingChanging from chlorine containing bleaching processes to chlorine free bleaching processesOnce again, our example for an improvement analysis will be copy paper. In this, the analyst needs to decide potential changes to the product design. This can range from trying to make the copy paper brighter to making it more eco friendly. It is up to the discretion of the group leading the LCA to decide what is the most important.Next, we need to look at the changes in raw materials. The analyst can present alternatives such as using secondary material and different chemicals that preserve the structural integrity of the paper and pollute less.Finally, the analyst must look at potential changes to the industrial process. One example of this is the change over from acidic papermaking to alkaline paper making. This required the addition of new steps and chemicals.
41 Interpretation: Your Turn Exercise: Interpret the results of your LCA and present them to the groupSignificant issues: Much of the impact of a PB&J comes from the transportation of the products.Examine for completenessRecommendationsRaw Materialanalyze higher yielding peanut strandsPackaginguse more environmentally friendly packagingManufacturingModify process to increase energy efficiency
42 Carbon Footprint Model for Bleached Pulp and Paper ProductsTrevor H. Treasure, Jesse S. Daystar and Richard A. Venditti*Department of Wood and Paper ScienceNorth Carolina State UniversityRaleigh, NC*Corresponding author:(919)42
43 Waste Paper What do we do with it all? More than 700 lb/person annual paper consumption in the USA40% of all municipal waste is paperWhat should be done with waste paper?With the increased threat of global warming, it is important to understand where greenhouse gasses are produced and how to minimize their production. With the large amount of paper produced, consumed and disposed of in the united sates, it is important to understand repercussions of different waste management and production methods.This analysis examines different waste management processes and determines the option with the smallest carbon footprint43
44 Life Cycle Assessment -Recycling Paper Products InterpretationImpact AssessmentInventory AnalysisGoal and Scope DefinitionThe following study is not a complete life cycle analysis. It only considers greenhouse gasses and does not include an impact assessment around these emissionsGoal and Scope definition: Identifies the intended purpose of the LCA and determines what items shall be considered.44
45 Goal and Scope Definition GoalsTo compare the carbon footprint of three waste management scenarios for copy paper1. Landfilling 2. Incineration 3. RecyclingTo perform a systematic and quantitative evaluation of these three waste management optionsTo provide a tool for consumers and waste management personnel for determining the best waste management practicesThe LCA model will be used to compare the carbon footprint of three different waste management scenarios for copy paper: landfilling, incineration, recycling.The goal is to compare the carbon footprint of these waste management techniques if they were used by themselves.45
46 Goal and Scope Definition Three waste management scenarios considered.LandfillingIncineratingRecyclingThis study will not consider the effect of recycling on the value of wood or its consequences on the wood marketA full impact assessment will not be performedThis analysis only accounts for carbon emissionsOther significant pollutants are emitted but are not accounted for in this study, example heavy metals46
47 Assumptions 1 of 2Increased recycle production has no effect on tree productionMethane emissions from land fills have been converted to carbon dioxide equivalents using a ratio of 21:1 (IPCC 1995, table 4, pg. 26)Avoided CO2 releases based on fuel mix for national electricity gridHeating value of copy paper 6213 BTU/lb (PTF White Paper No.3)Net heating value of methane 21,433 BTU/lb (engineeringtoolbox.com)47
48 Assumptions 2 of 2Responsible silviculture replant to harvest ratio equals 1:1Carbon sequestration based on wood makeup and weight percent carbon of cellulose, hemicelluloses, and ligninAll mills are considered to be average in energy and production efficiencyOffice paper is assumed to be 20% inert, inorganic filler materialOffice paper fibers: 20% softwood and 80% hardwood48
49 Life Cycle Assessment -recycling paper products InterpretationImpact AssessmentInventory AnalysisGoal and Scope DefinitionInventory analysis: identifies the major steps of the life cycle and analyzes the associated requirements (materials needed, energy required, etc) and the wastes produced at each step.49
50 Raw Material Composition Paper Composition% % Soft Wood20%% Hard Wood80%ComponentSoftwoodHardwoodCellulose42%45%Hemicellulose27%30%Lignin31%25%Component% carbon by weightMajor Hemicellulose - SW44.68%Minor Hemicellulose - SW47.31%Major Hemicellulose - HW37.76%Minor Hemicellulose - HW43.60%Lignin60.93%Office paper for this analysis is assumed to be 100% fiber. Based on 100% fiber 20% is hardwood while 80% softwood. Both softwood and hard wood have different chemical compositions. This must be taken into account when calculating the carbon sequestered in tree growth.Trees are made up of Cellulose, Hemicellulose and Lignin. Each of component has a certain percentage of carbon per mass. Cellulose is the most carbon rich component and sequesters the most carbon.Pine tree:Source: Dr. Dimitris S. Argyropoulos, course pack for WPS 33250
51 Carbon Equivalents Carbon Equivalents Conversion ` CO2 Tons 12 g carbon/mol=Carbon Equivalents44 g CO2/molMethane Tons12 g carbon/mol=Carbon Equivalents16 g CH4/mol12+(4x1)=16Methane Tons combusted12 g carbon/mol=Carbon Equivalents16 g CH4/mol51
52 Process Flow Diagram 1 of 2 Virgin Production + Landfilling Energy/fuelCO2 EmissionsEnergy/fuelCO2 EmissionsFillerThe production, use and disposal of office paper can be broken down into several unit processes. Emissions can then be calculated for each unit process. The tree growth process sequesters 823 tons of carbon. Tree harvesting, paper mill production, and transportation to market all release carbon into the environment.smoke stackCo2 signCoal TrainGas PumpEnergy/fuelCO2 Emissions52
53 Process Flow Diagram 1 of 2 Energy/fuel=0CO2 Emissions=0CO2 EmissionsEnergy/fuelEnergy/fuelCO2 EmissionsMethane EmissionsWhen the waste paper reaches the landfill it will decompose and produce methane. This methane can be dealt with in a number of ways. First it can be released into the environment as methane. Second, it can be flared which produces CO2 which is 21 time less potent of a green house gas than methane. Finally, and most environmentally friendly, methane can be combusted to make electricity. This electrical production is then considered a carbon credit which offsets the processes total emissions. The carbon not converted to methane is either sequestered in the ground or released as CO2.Paper prod Picture:Carbon Stored in landfillElectricity production53
54 Process Conversions 1 ton methane is equal to 21 ton CO2 equivalents lb CO2Per tonSourceGreen Wood Transportation305Green woodPaper Task Force White PaperVirgin Production2995PaperTransportation to Market33Collection and Landfill Equipment84Landfill% by wieghtSourceCO2 Landfill Emmisions15.2%Paper task force white papersMethane Landfill Emissions22.9%Carbon Sequestured61.9%Mathane Recovered50.0% Assume 50% (CORRIM)CO2 from Methane Combustion75.0%Carbon Offset from Electrical ProductionSourceCO2 Offset from Electrical Production127CO2 lbs per MMBTUPaper Task Force White PaperNet BTU21433BTU per lb MethaneEngineering Tool Box1 ton methane is equal to 21 ton CO2 equivalents54
55 Virgin Production + Landfill Energy Requirements and Carbon Emissions MMBTUUNIT PROCESSEmissionsTon Carbon EquivalentsTree Growth-7911909Tree Harvest and Transport13937913Paper Mill1418205Paper Transport to Market4.5~0Use of Product527Collection Vehicle & Landfill Equipment11.5-1863Landfill30.538690Total812Negative values represent either energy created or carbon sequestered55
56 Process Flow Diagram 1 of 2 Virgin Production + Incineration CO2 EmissionsEnergy/fuelEnergy/fuelCO2 EmissionsThe first part of this process is identical to the landfill scenario. Each unit process uses energy and has a corresponding CO2 emissions.smoke stackCo2 signCoal TrainGas PumpEnergy/fuelCO2 Emissions56
57 Process Flow Diagram 2 of 2 Energy/fuel=0CO2 Emissions=0Energy/fuelCO2 EmissionsEnergy/fuelCO2 EmissionsThis half of the process adds another unit process before landfilling. The waste paper is burned to produce electrical energy which is then put back into the grid. The electricity production is assumed to offset electricity produced elsewhere creating carbon credits for this process. The amount of carbon credits assigned is based on the national average carbon emitted per unit of energy produced.CO2 EmissionsMethane EmissionsCarbon57
58 Virgin Production + Incineration Calculations Incinerator carbon equivalents emissions=tons carbon in woodVirgin paper mill yield %Fiber in paperEnergy produced from paper combustion=tons papertons virgin production6213 BTU2000 lbslb paperton1,000,000 BTU1 MMBTUWhite paper #3Incinerator carbon equivalents emissionsCarbon in wood X PM Yield% X %fiber in paperEnergy produced from paper combustionTons paper*6213btu/lb paper1*2000/1,000,000Landfill ashEqual to the filler content58
59 Ton Carbon Equivalents Virgin Production + Incinerate Energy Requirements and Carbon EmissionsEnergyMMBTUUNIT PROCESSEmissionsTon Carbon EquivalentsTree Growth-7911909Tree Harvest and Transport138.637913Paper Mill1418205Paper Transport to Market4.5~0Use of Product0.0297Collection Vehicle & Landfill Equipment6.5-11643Incineration89.028680Total866UnitsNegative values represent either energy created or carbon sequestered59
60 Process Flow Diagram 1 of 3 Recycled Production + Recycling Energy/fuelCO2 EmissionsEnergy/fuelCO2 EmissionsEnergy/fuelCO2 EmissionsThe recycling production has several more steps than the previous two processes. One major difference is that there is no carbon sequestered in the feed stock. Since the feedstock is recycled paper, it would be redundant to account for carbon sequester for recycling and for the virgin production. Instead, the model accounts only for the carbon that is stored in the paper after its production and use.Truck picture:Energy/fuelCO2 EmissionsFillerRejects to waste treatment60
61 Process Flow Diagram 2 of 3 Recycled Production + Recycling Energy/fuelCO2 EmissionsEnergy/fuel=0Carbon sequestered in productPossible decrease in demandOne scenario that this model does not attempt to analyze is the effect of recycling on the wood market. Some possible outcomes of increased recycling could be decreased demand and value of pulp wood. Decreased demand might motivate tree farmers and land holders to find more profitable uses for their forest land. The model does not consider these cause and affect situations. The model assumes that the tree production is independent of recycling production.NOTE: Tree growth loss is assumed to be zero for this studyForest used in more profitable ways such as construction61
62 Process Flow Diagram 3 of 3 Recycled Production + Recycling Energy/fuelCO2 EmissionsCO2 EmissionsMethane EmissionsSince fibers cannot be recycled indefinably, there are some rejects from the paper mill that are sent to the landfill. The model assumes that 85% of the fibers can be reused (Recycled Fiber and Deinking).Reference: Gottshing, Lothar; Pakarinen, Heikki; Recycled fiber and Deinking, p. 510, rejects superior grade to graphic paper62
63 Recycled Production + Recycle CalculationsRecycled Production + RecycleCarbon sequestered in use=tons carbon in woodTons virgin productionVirgin paper mill yield %Tons recycled papertons organicsFiller content(1-.382)Carbon sequestered in landfill=Paper Task Force: White PapersTons organics in sludge=Tons recycled paper% FillerTotal sludge63
64 Recycled Production + Recycle Energy Requirements and Carbon Emissions MMBTUUNIT PROCESSEmissionsTon Carbon Equivalents989Recovered Paper Collection26.5283Material Recovery Facility5.3205Transport to Recycle Mil620300Recycle Paper Mill470Transportation to Market4.5Use-380227Collection Vehicle and Landfill Equipment4.9-1133Landfill1921077Total156.1Negative values represent either energy created or carbon sequestered64
65 Unit Process Emissions All values are tonsVirgin Prod. + LandfillVirgin Prod. + IncinerateRecycle Prod. + RecycleCarbon sequestered in tree growth-791N/ARaw material acquisition13937.3Paper mill production1418470Transport to market4.5Carbon sequestered in product-395Collection and landfill equipment/ sorting1164.9Landfill265.10.0161Carbon sequestered in landfill-235-143Incinerate89Total Carbon Equivalents812866141Total Carbon Equivalents per ton0.8120.8660.141Note:Negative values represent carbon sequesteredThe recycling paper mill process emits much less carbon equivalents than the other two optionsCO2 emissions for recycling production are much less than virgin productionCarbon sequestered in the recycling process is sequestered in the product. For virgin production it is accounted for in the growing of treesCO2 emissions for landfilling are much less in the recycling processLandfilling (emissions-credits)65
66 % Difference From Landfilling Carbon Equivalents Emissions Comparison % Difference from LandfillingLandfill reported in tons for comparisonVirgin Prod. + LandfillVirgin Prod. + IncinerateRecycle Prod. + RecycleRaw material acquisition1390%-73%Paper mill production1418-67%Collection and landfill equipment/ sorting11-44%-57%Landfill265-100%-39%Carbon sequestered in landfill-235Total Carbon Equivalents8127%-83%Total Carbon Equivalents per ton0.812This table shows the percent change but not the magnitude.The total carbon equivalents per ton is 68% less for the recycling option while it is 11% more for the incinerationThe emissions due to the paper mill are decreased by 60% for recycled paper. This is not the largest percent change but it’s magnitude is the largest.Incinerating greatly decreased the landfill emissions. This is a result of burning the majority of the material and only sending the ashes to the landfill.66
67 Sensitivity Analysis Virgin Production + Landfill Sensitivity Analysis on Carbon Equivalents per ton for Virgin Production + LandfillPercent Change10%-10%% Change from base CaseSoftwood %0.8080.8170.58%Transportation emissions0.8280.7971.90%Landfill methane recovery0.7630.8626.12%Base case value of .812 carbon equivalents per ton of productionLandfill methane recovery rate has the largest impact on carbon emissionsMethane is 21 times more harmful than CO2A sensitivity analysis illustrates the effects different process parameters have on the total carbon equivalents per tonHere the virgin production and landfilling scenario is considered. The softwood/hardwood blend and transportation emissions do not affect the total carbon equivalents by more than 1%The process is highly sensitive to the methane recovery rate. Here, values of 40 and 60 percent recovery were examined. A 10% change in methane recovery rate changed the overall carbon equivalents by around 6%.67
68 Sensitivity Analysis Virgin Production +Incinerate Sensitivity Analysis on Carbon Equivalents per ton for Virgin Production + IncineratePercent Change10%-10%% Change from base CaseSoftwood %0.8630.8690.35%Transportation emissions0.8810.8511.73%Landfill methane recovery0.8660.00%Base case value of .866 carbon equivalents per ton of productionThe carbon emissions of this waste management practice are not greatly impacted by these sensitivitiesThe virgin production and incineration option was less sensitive to these parameters Transportation was sensitivity had the largest impact in this management option.68
69 Sensitivity Analysis Recycled Production + Recycling Sensitivity Analysis on Carbon Equivalents per ton for Recycled Production + RecyclePercent Change10%-10%% Change from base CaseSoftwood %0.1410.00%Transportation emissions0.1450.1362.95%Landfill methane recovery0.1100.17121.50%Base case value of .141 carbon equivalents per ton of productionLandfill methane recovery rate has the largest impact on carbon emissionsTransportation emissions significantly impacted the totalFor recycling production and recycling, methane recovery has a large impact on the total carbon equivalents. The recycling mill rejects are sent to the landfill where they produce methane.69
70 ton C produced/ton paper InterpretationWaste Management Methodton C produced/ton paperVirgin Production + Landfill0.650Virgin Production + Incinerate0.725Recycle Production + Recycle0.207The Recycling scenario has the smallest carbon footprintLandfill carbon footprint is highly dependent on the methane recovery rateIncreased recycling may reduce green house gas emissionsIncreased recycling may impact the wood marketThese impacts are outside the scope of this study70
71 Interpretation: Environmental Improvement Opportunities Potential Process ImprovementIncrease methane recovery in landfillsDecrease transportation of products and raw materialsIncrease paper production efficiencyEnergyUse renewable transportation fuelsUtilize renewable electrical powerIncrease energy efficiency in production process71
72 Wood for Building Houses An Example of LCA Adam TaylorAssistant Professor Forestry, Wildlife & Fisheries 203 Forestry Products, 2506 Jacob Drive Knoxville, TN 37996 Phone:72
73 What Do You Think? http://www.ussi.ca/residential_steel.html Substitutes for wooden building materials are often promoted on the basis of environmental benefits. In this case, the steel industry is advocating the use of steel framing to save trees. This seem logical but what do you think? Are there other factors that need to be considered?73
74 AcknowledgmentAll of the information in this presentation is based on work conducted by CORRIM74
75 CORRIM Consortium for Research on Renewable Industrial Materials Aims to provide a database of information for quantifying the environmental impacts and economic costs of building materialsThe Consortium for Research on Renewable Industrial Materials (CORRIM) was organized to update and expand a 1976 report by the National Academy of Science regarding the impacts of producing and using renewable materials. The original report focused specifically on the energy impacts associated with using various renewable materials. Since the 1976 report was written a variety of environmental issues and energy-related concerns have surfaced, yet little scientific or quantifiable information regarding these issues and concerns has been gathered. Without a scientifically sound database of the environmental and economic impacts associated with using renewable materials, it is difficult for policymakers to arrive at informed decisions affecting the forestry and wood manufacturing industries. Moreover, individual industries, including those that use wood as a raw material have little information available to them that could provide a basis for strategic planning and investments to improve their environmental stewardship. The new CORRIM report aims to provide a database of information for quantifying the environmental impacts and economic costs of wood building materials through the stages of planting, growing, manufacturing, construction, operational use, and demolition.75
76 MotivationThe environmental consequences of changes in forest management, product manufacturing, and construction are poorly understoodLack of up-to-date, scientifically sound, product life-cycle data in the United States, particularly life-cycle data regarding wood and bio-based productsFor example, concerns about the sustainability of present forest practices have lead to changes in forest harvesting in the US. As a result, the US wood products sector has lost a substantial market share to non-wood substitutes and foreign suppliersMotivation for Creating CORRIM: Public interest in the environmental impacts of forest management has reached new heights, resulting in a demand for strategies and policies to improve environmental performance. Unfortunately, the environmental consequences of changes in forest management, product manufacturing, and construction are poorly understood, and ironically, may be detrimental to global environmental quality. This situation is greatly accentuated by an almost total lack of up-to-date, scientifically sound, product life-cycle data in the United States, particularly life-cycle data regarding wood and bio-based products.For example, concerns about the sustainability of present forest practices have lead to changes in forest harvesting in the US. As a result, the US wood products sector has lost a substantial market share to non-wood substitutes and foreign suppliers.Ultimately, concerns about forests and the wood produced have a direct and significant impact on the US building materials and home building industries. Harvest reductions are quickly reflected in the availability of wood, and in turn, the price of building materials. This triggers consumers to use wood from other regions of the world or use non-wood substitutes. While the economic impacts have been analyzed and reported, the environmental consequences of these changes in material flow and uses are poorly understood.Decisions that discourage the use of wood and other non-wood building products are made each day at all levels of industry and government. While many decisions may be motivated by a desire to protect the environment, individuals making these decisions may not consider the negative consequences associated with using non-wood substitutes.Consequences include the impacts that non-wood products can have on the environment and the impacts that management can have on forestland. The decision to avoid using wooden building materials is often counterproductive to the intent. It is critical that a better information base of quantitative data regarding the environmental impacts of a variety of building products be developed. Decisions based on quantitative or scientific information is needed to have a more positive effect on the environment and economy.76
77 Mission: To create…A consistent database to evaluate the environmental performance of wood and alternative materials from resource regeneration or extraction to end use and disposal, i.e., from "cradle to grave. (Figure 1).A framework for evaluating life-cycle environmental and economic impacts.Source data for many users, including resource managers, manufacturers, architects, engineers, environmental protection and energy analysts, and policy specialists.An organizational framework to obtain the best science and peer reviewMission: The 1998 CORRIM research plan proposes to develop a scientific base of information relating to the environmental performance of wood based building products. The plan identifies several factors that can affect the efficient use of energy and materials in building materials manufacturing. These factors include appropriate forest management and methods to increase carbon sequestration, improve the efficiency of manufacturing processes, reduce waste and potentially toxic materials, and sustain healthy forest ecosystems. The intent is to create:• A consistent database to evaluate the environmental performance of wood and alternative materials from resource regeneration or extraction to end use and disposal, i.e., from "cradle to grave. (Figure 1). • A framework for evaluating life-cycle environmental and economic impacts.• Source data for many users, including resource managers, manufacturers, architects, engineers, environmental protection and energy analysts, and policy specialists.• An organizational framework to obtain the best science and peer review77
78 Membership in CORRIM Research Institutions and Voting Board Members University of WashingtonOregon State UniversityUniversity of MinnesotaUniversity of IdahoFORINTEK, CanadaVirginia TechNorth Carolina State UniversityPurdue UniversityUniversity of MainePenn State UniversityState University of New YorkAPA, The Engineered Wood AssociationWestern Wood Products AssociationComposite Panel Association Research FoundationWashington State UniversityLouisiana State UniversityMississippi State University78
79 Life Cycle Assessment -applied to building products InterpretationImpact AssessmentInventory AnalysisGoal and Scope DefinitionThe following are the normal steps for a LCA.Goal and Scope definitionInventory analysisImpact assessmentInterpretationGoal and Scope definition: Identifies the intended purpose of the LCA and determines what items shall be considered.79
80 GoalsTo develop a database and modeling system for environmental performance measurements associated with materials useTo respond to specific questions and issues related to environmental performance and the cost effectiveness of alternative management and technology strategies.Objectives: CORRIM’s research is focused on two objectives: 1) to develop a database and modeling system for environmental performance measurements associated with materials use and, 2) to respond to specific questions and issues related to environmental performance and the cost effectiveness of alternative management and technology strategies. This database and information source will enable decision-makers to make consistent comparisons and systematically characterize the options for improving environmental performance. By comparing across alternatives, the analyses will reveal marginal costs that contribute to marginal environmental changes and other economic impacts. This type of analysis also provides projections of future environmental performance. Examples include:A systematic evaluation and quantification of the environmental performance of wood products and wood-using systems: Alternatives for improving energy efficiency, carbon sequestration, recycling, reuse, and sustainability with tradeoffs between environmental and economic performance measures.An assessment of how changes in forest culture and wood use affect forest health and the nation’s energy requirements.The likely impact of mandated carbon-emission reductions, carbon taxes, or tradable permit systems on forest culture and forest product use.A thorough examination of ways to conserve wood.80
81 Scope Houses built with different materials Minneapolis (cold climate) - wood & steelAtlanta (warm climate) - wood & concrete81
85 Life Cycle Assessment -applied to building products InterpretationImpact AssessmentInventory AnalysisGoal and Scope DefinitionThe following are the normal steps for a LCA.Goal and Scope definitionInventory analysisImpact assessmentInterpretationInventory analysis: identifies the major steps of the life cycle and analyzes the associated requirements (materials needed, energy required, etc) and the wastes produced at each step.85
86 Life Cycle Inventory Analysis for Wood Building Materials Forest Management (Regeneration)(Transportation)EMISSIONSRaw Material Acquisition (Harvest)EFFLUENTSMATERIALS(Transportation)SOLID WASTESProduct ManufacturingENERGY(Transportation)OTHER RELEASESCollected survey data (regional): Regeneration and forest management, Harvesting Product Manufacturing (lumber, plywood, OSB, other) Building: designed (to code), construction, occupation and use through final demolition.Building ConstructionWATER(Transportation)Use/MaintenancePRODUCTS(Transportation)COPRODUCTSRecycle/Waste Management(Transportation)86
87 System Boundaries Forest Resources: NW and SE (25-100+ years) Harvesting ( < 1 Year) logs NW and SEProcessing ( < 1 Year)lumber SE and NW (green and dry) plywood NW and SE OSB SE Glulam, LVL, I-JoistsConstruction ( < 1 Year)wood and steel Minneapolis (cold) wood and concrete Atlanta (warm)Use and Maintenance (40 – 100+ years)Disposal (< 1 Year)“Cradle”“Gate to Gate”“Grave”87
88 Regional product detail Multi-material detail Regeneration to waste disposal Primary source for wood data Secondary source for non wood data (ATHENA)Boundaries:Regional product detailMulti-material detailEnvironmental Performance:Air, water, toxic substances, energy, carbon, wastemid-point parameters for human health riskStrategic Research Plan (1998)Study Guideline (2000) – ISO consistentProtocol:88
89 Building Product LCI’s For building productsfor lumber, plywood, OSB, LVL, glulam, I-joists, trussesUnit process descriptions (saw, dry, plane etc.)Mill surveys at unit process levelNon-wood inputs (energy by source, raw materials)Emissions and solid waste outputsYields, flows (co-products) and mass balancesUnit factor estimates (raw materials, air, water, and solid emissions, energy, carbon) before and after impacts from purchased energy and transportation89
90 U.S. LCI Database Project ATHENA & NRELPublicly available info on common materials, products and processesCould lead to “eco-impact labels”similar to food labeling90
91 Life-Cycle Inventory results 1.0 MSF 3/8-in. basis plywood production INPUTSOUTPUTSMaterialsUnitsPer MSFMaterialsUnitsPer MSF3/8-in. basis3/8-in. basisBarkft.36.56E+01Bark wasteBark ashTotalProductsPlywoodCo-productsWood chipsPeeler coreGreen clippingsPanel trimSawdustAir emissionsAcetaldehydeAcetoneAcroleinBenzeneCOCO 2 fossilDust (PM10)FormaldehydeMethanolNO xParticulatesPhenolSO 2SO xlb.1.31E+01Wood/resinlb.1.89E+037.75E+00Roundwood (log)2.09E+01lb.1.59E+01Phenol-formaldehydealb.8.90E+009.91E+02Extender and fillerslb.1.11E+004.25E+02Catalyst alb.3.30E-014.62E+01lb.1.98E+023.10E+01Soda ash aVeneer downfall3.44E+00Bark blb.6.81E+001.07E+02Dry veneerlb.1.51E+019.63E+00Solid dry veneer6.68E+01Green veneer6.89E+02Electrical energyElectricitykWh1.39E+021.12E-024.80E-03Fuel for energyb4.95E-07Hog fuel (produced)blb.3.83E+024.77E-04Results include plywood production only; no emissions are included for the production and use of electricity, fuel, and phenol-formaldehyde resin.There are many inputs and outputs to consider. A weakness of the LCA process is the difficulty of collecting all of this information.1.91E+00Hog fuel (purchased)lb.3.40E+012.78E+02Wood wastelb.5.00E-01CO 2 non-fossil2.78E+02Liquid propane gasgal.3.59E-012.08E-011.80E-02Natural gasft.31.63E+021.28E-01Dieselgal.3.95E-012.34E-01Organic substances2.20E-02a These materials were excluded based on the 2% rule.3.47E-018.27E-03b Bark and hogged fuel are wet weights whereas7.74E-04all other wood materials are oven dry weights;1.01E-01bark weight is included in the “hog fuel (produced)” weight.VOClb.6.26E-0191
92 Life Cycle Assessment -applied to building products InterpretationImpact AssessmentInventory AnalysisGoal and Scope DefinitionThe following are the normal steps for a LCA.Goal and Scope definitionInventory analysisImpact assessmentInterpretationImpact assessment: An impact analysis “aims to examine the product system from an environmental perspective using impact categories and category indicators connected with the [inventory analysis’] results. The [impact assessment] phase also provides information for the life cycle interpretation phase.” (ISO 14042)92
93 An example of LCI comparisons: Minneapolis Steel minus WoodExtraction (primary materials in kg)Values are for steel example (Minneapolis option) minus wood option . The wood frame house option uses more wood (thus the negative value for wood fiber) but less of the other inputs.93
94 An example of LCI comparisons : Atlanta Concrete minus WoodExtraction (primary materials in kg)Values are for concrete example (Atlanta option) minus wood option . The wood frame house option uses more wood (thus the negative value for wood fiber) but less of other inputs.It takes almost 3,000 kg of limestone and a much larger amount of aggregate to replace the 2,500 kg of wood fiber required for the KD-wood design. The furred out wood frame used to house the insulation for the concrete block exterior wall uses only slightly less wood than for the KD-wood design94
95 GWP: Minneapolis and Atlanta Global Warming Potential IndexCO2 Equivalence Effects: (CO2, N2O, CH4)95
96 Summary - Minneapolis Building Other Design vs. Wood (% Change) Minneapolis designWoodSteelDifferenceOther Design vs. Wood (% Change)Embodied Energy (GJ)65176411317%Global Warming Potential (CO2 kg)37,04746,8269,77926%Air Emission Index (index scale)8,5669,7291,16314%Water Emission Index(index scale)177053312%Solid Waste(total kg)13,76613,641-125-1%96
97 Summary - Atlanta Building Other Design vs. Wood (% Change) Atlanta DesignWoodConcreteDifferenceOther Design vs. Wood (% Change)Embodied Energy ( GJ)3984616316%Global Warming Potential (CO2 kg)21,36728,0046,63731%Air Emission Index(index scale)4,8936,0071,11423%Water Emission Index70%Solid Waste(total kg)7,44211,2693,82751%97
98 Other Studies – Same Results 1992 New Zealand studyWood office building 55% of energy/70% carbon versus concreteSteel wall 4x energy of wood wall1992, 1993 Cdn studiesWood 1/3 energy and CO2 versus steel and concreteWood consistently lower emissions and less energy98
99 Life Cycle Assessment -applied to building products InterpretationImpact AssessmentInventory AnalysisGoal and Scope DefinitionThe LCI data require interpretationInterpretation: “The objectives of life cycle interpretation are to analyze results, reach conclusions, explain limitations and providerecommendations based on the findings of the preceding phases of the LCA or LCI study and to report the resultsof the life cycle interpretation in a transparent manner.” (ISO 14043)99
100 Not All Energy is EqualMuch of the total energy needed to process wood is provided by biofuels from mill residuals and does not contribute to carbon emissions since the forest carbon is CO2 neutral. Increased use of biofuels could reduce the emissions even more for wood products. OSB releases substantially more emissions because it uses more resins.While the equivalent emissions from steel or concrete will be highly dependent upon use, it is relatively easy to compare the impact of a concrete slab floor to the equivalent of a cubic meter of wood floor with joists.The chart ignores the carbon stored in the wood products.100
101 Emissions to Water: Minneapolis Not all pollution is equalWorst offending toxin exampleCompare output to EPA acceptable limits for the pollutant.101
102 Emissions to Water: Minneapolis On Equal Health Risk Basis 102
103 Energy in Building Life Cycle Minneapolis HouseAtlanta HouseWoodSteelConcreteStructure (GJ)646759395456Maintenance (GJ)73110Demolition (GJ)79Embodied energy total (GJ)72784051257375 years of heat &cooling energy (GJ)78004575Energy used during building use is much greater than the energy embodied in the structure. These buildings were designed to have equivalent performance in terms of heating costs. Changes to the design that reduce the need for heating and cooling could have a larger impact on total energy usage than the types of building materials used.103
104 Carbon Dynamics vs. Steady State LCI provides a cross sectional profile of all processes -- a steady state analysisTracking carbon pools over time offers a dynamic alternative for a more financial cost/benefit perspectiveLCA’s steady-state analysis is a weakness of the process. Dynamics of carbon (or other renewable resources) are not considered. The time value of money is also not considered.104
105 The fact that wood products store carbon is independent of the energy required to produce products. Since forest carbon is neutral on any given sustainable rotation, the carbon in the portion of the log that ends up in products extends the carbon stored in the forest to storage in products which subtracts from the carbon emissions to produce the product for the life of the product. The net carbon impact of using wood products i.e. carbon emissions from energy used less the increased carbon stored in the product is substantially better than carbon neutral. While OSB is more energy intensive, it is also more dense and stores the most carbon over the product life offsetting the greater use of energy. Concrete does not store carbon but may absorb a small amount of CO2 over its life (not shown).The question of what happens at end of life depends upon if the product is recycled in product, collected as a biofuel for energy, land filled or burned as waste. The worst case of burning as waste losses the carbon stored as shown in the prior chart. With the higher cost of fossil fuels i.e. higher value of carbon in the future such as expected from a carbon tax or cap and trade system, most wood products will likely be collected for not less than their energy value. If collected and used as a coal substitute the chart is unchanged as the carbon stored in product is transformed to a permanent displacement of coal energy emissions, since wood and coal heating values are similar.105
106 Concrete frame/wood frame Atlanta Steel frame /wood frameMinneapolisSteel frame/wood frameMinneapolisThe figure shows the GWP (carbon eq) emissions from the steel and concrete house relative to wood house i.e the steel house emits 26% more emissions than the wood house even though only 6% of the mass of the house was changed from steel to wood not including the carbon stored in the wood. When the carbon stored in the wood is included it substitutes for many of the emissions produced by the building and hence the steel house is actually 120% higher GWP than the wood house.The concrete house is somewhat higher at 31% higher emissions before accounting for the wood in the house and 156% higher when it is included.106
107 Carbon In Forest Pools Harvest rotation years FIA data on old stands No harvest44, 80, 120 yr rotations, no action, & empirical old stands.Killing and removing trees reduces the carbon in the forest. Carbon is retained in wood products or in paper for a period of time.Harvest rotation years107
108 Carbon Dynamics Need to be Considered Averages over time intervalsCARBON DYNAMICS IN FORESTS, WOOD PRODUCTS AND (CONCRETE) SUBSTITUTESThe ‘rotation length’ is the time between forest harvests.When you can ‘substitute’ wood for more fossil-carbon-intensive materials (such as concrete), you are reducing GWP.108
109 Carbon Emissions in Representative Building Life Cycle Stages CO2Minneapolis HouseAtlanta HouseMetric TonsWoodSteelConcreteEmissions in MfgConstruction & Demo37.146.821.428.0Emissions from Biofuel18.104.22.168.7Emissions from Maintenance4.1Emissions from Heating & Cooling390232Subtotal of Sources434443261267Forest Sequestration(467)(246)(103)(85)Wood product Storage(22.4)(11.8)(17.1)(14.1)Subtotal of Sinks and Stores(489)(258)(121)(100)Net emissions(55)185140167109
110 Interpretation: Environmental Improvement Opportunities Redesign the houseuse less fossil-intensive products (wood is good!)reduce energy use (both active and passive)improve durability to increase useful lifeImprove the productgreater use of biofuelengineered products for greater raw materials efficiencyincrease process efficiencies, especially in dryingpollution control improvementsincrease product durabilityReduce, reuse and recycle demolition wastes110
111 LCA Strengths & Weaknesses ProSystem wideQuality and objectivityMultiple impact factorsConDependent on quality of LCILCI difficult to establishSteady stateResources changeTime value of money111
112 Life Cycle Assessments Biomass to Ethanol from Different Regional feedstocksJesse Daystar, Richard Venditti* Based on work of Kemppainen and ShonnardDepartment of Wood and Paper ScienceNorth Carolina State UniversityRaleigh, NC*Corresponding author:(919)112
113 Biomass to Ethanol Potential ethanol production U.S. Department of Agriculture Biomass EstimationEstimated 3.56 million dry tons on a sustainable basis in U.S. per day2U.S. Oil Consumption868.6 million gallons/day1Potential ethanol production9.58 million gallons per day of oil equivalents2113
114 Life Cycle Assessment -applied to cellulosic ethanol InterpretationImpact AssessmentInventory AnalysisGoal and Scope DefinitionThe following are the normal steps for a LCA.Goal and Scope definitionInventory analysisImpact assessmentInterpretationGoal and Scope definition: Identifies the intended purpose of the LCA and determines what items shall be considered.114
115 GoalsTo compare the environmental impacts of two processes that utilize different regional cellulosic feedstocks to produce ethanol.Yellow Poplar regional to MichiganRecycled Newsprint115
116 Scope "Cradle to gate” Different from “cradle to grave” Acquisition of raw material through production of ethanolDifferent from “cradle to grave”Will not investigate the impacts of the use of ethanolWhy Cradle to Gate?End use of ethanol for both alternatives is identicalCradleProduction Gate116
117 Life Cycle Assessment -applied to cellulosic ethanol InterpretationImpact AssessmentInventory AnalysisGoal and Scope DefinitionThe following are the normal steps for a LCA.Goal and Scope definitionInventory analysisImpact assessmentInterpretationInventory analysis: identifies the major steps of the life cycle and analyzes the associated requirements (materials needed, energy required, etc) and the wastes produced at each step.117
118 Simulation and Modeling Yellow Poplar diesel & gasolineFelling & SkiddingChippingEthanol ProductionPre-manufacturingdieselTransportationelectricityRaw material & energyBoustead ModelEmissions Factors & EFRATASPEN Simulation & EFRATThe process is split into two different sub processes: pre-manufacturing and manufacturing. The Boustead model is used to calculate the emissions from the pre-manufacturing stage while the ASPEN model is used to calculate emissions from the production stage. EFRAT software is used to calculate the environmental impact for both sub processes.Here chipping is included in the manufacturing stage because chipping is part of the NREL ASPEN model.118
119 Simulation and Modeling News Print diesel & gasolineCollection & SortingPulpingEthanol ProductionPre-manufacturingdieselTransportationelectricityRaw material & energyBoustead ModelEmissions Factors & EFRATASPEN Simulation & EFRATAgain the production process I split into two subcategories. Here the Boustead Model is used to calculate emissions of pulping and all other processes and emissions in pre-manufacturing stage. The APSEN model was originally designed to use a wood feedstock. As a result, it has no modeling capabilities for pulping.119
120 Feedstock Composition % dry wt basiscomponentYellow Poplar(NREL)3Yellow Poplarupper Michigan timbernewsprintcellulose42.649.1563.77xylan19.0516.895.26arabinan0.791.040.61mannan3.933.764.96galactan0.241.01acetate4.643.380.00lignin27.6824.4521.26ash1.000.313.54moisture47.968.45.0The Yellow Poplar native to Michigan has a similar composition to NREL Poplar. The Michigan timber has higher cellulose and a lower moisture percentages.The newsprint substantially higher cellulose percentage and a much lower moisture content. This is an advantage when transporting the raw material.120
121 Boustead Model Standard Data Sets Custom Data Sets Transportation distances, materials used, utilitiesThe Boustead Model is a computer modeling tool for life cycle inventory calculations. It calculates inventories on a per unit product basis. It can be customized to track unique compounds. Already built into the model, there are many common pollutants and feedstocks data.This model was used in the inventory analysis to calculate the emissions of the pre-manufacturing processes for the both scenarios.Life Cycle Inventory Results121
122 NREL Process Modeling Modeling software ASPEN Developed by M.I.T. and the Department of EnergyProcess modelingProcess optimizationASPEN is one of leading chemical process simulation software packages. The process model used for this study was designed by NREL using ASPEN.Here is a screen shot of a process in ASPEN.Life Cycle Inventory Results122
123 Pre-manufacturing Energy Usage upper MI timbernewsprintKg/hMJ/hPremanufacturing, Chemicalsammonia1,19488,62063847,370ammonium sulfate1082,2161693,376antifoam26821,62835628,696calcium phosphate1,1611,899diesel470557gasoline9381,0889781,134lime6938,1245706,647sulfuric acid1,8399,4951,6808,651subtotal132,88997,773Premanufacturing, Operationsfelling (gasoline)211,688skidding (diesel)33transportation (diesel)1576,7522329,917chipping (gasoline)12633pulping (electricity)9,07311,28918,990This table lists all the pre-manufacturing energy usages.In both processes, ammonia has the largest energy association. Pretreatment and detoxification unit process consumes large amounts of ammonia in both processesThe timber process has a much smaller electricity usage in chipping than the newsprint has in pulping.The newsprint has a higher transportation energy usage.123
124 Simplified Process Flow Ammonia, Lime, AcidFeed HandlingPretreatment (Detoxification)Hydrolysis & FermentationProduct & Water RecoveryEthanolStorageWaste CombustionUtilitiesWaste Water Treatment(Solid Separation)CellulaseElectricitySteamFeedstockRecycle waterEnzymeChipsSugarsRecycle WaterNutrientsAirSteamExcess CondensateThis simplified process flow diagram shows the major unit processes and streams.Each unit process and feed material has an impact that is accounted for in the inventory analysis.Feed Handling: Moves chips from piles onto conveyers and into reactorsPretreatment: This process converts the hemicelluloses to sugarsCellulase: This process uses sugars from the pretreatment in conjunction with other nutrients to grow the enzymes needed to hydrolyze the celluloseHydrolysis and Fermentation (SSF): In this process enzymes break down cellulose into sugars then yeast ferments those sugars to produce alcoholsProduct and Water Recovery: The mixture of ethanol, water, and by products is separated and the ethanol is purified to 99.5%Waste Combustion: Lignin and unreacted solids are combusted to create process steam and electricityWaste Water Treatment: Here process water is cleaned for further use and solid waste is processedStill Solids124
125 Detailed Process FlowThis is a more detailed flow diagram with mass flows and an energy balance. This process flow was made by Kemppainen and Shonnard.125
126 Energy Balance Upper Michigan Timber Process loses 9.7% of total energy through processes inefficiencies30% of total energy consumed in cooling water systemThis is higher than newsprint due to higher boiler throughputEnergy balance has an accuracy of 2%
127 Energy Balance News Print 2.2% more energy leaves with ethanol product for newsprint compared to timber processEnergy balance has an accuracy of 0.3%The cooling water system energy requirement is less for the newsprint process. This results from lower lignin biomass and lower boiler throughput.
128 Process Air EmissionsHere is the inventory of the chemical emissions that occur in both processes.As seen in previous slides, ammonia is a serious emission that mostly occurs in the pre-manufacturing process.Carbon dioxide contributes most to the total emissions. In the newsprint process, more carbon dioxide is emitted due to purchased electricity from utilities.
129 LCA Progress So Far So far we have Defined scope ☐So far we haveDefined scopeDefined goal/objectivePerformed inventory analysisPerformed energy balanceNextImpact assessmentLCA interpretationLCA improvement☐129
130 Life Cycle Assessment -applied to cellulosic ethanol InterpretationImpact AssessmentInventory AnalysisGoal and Scope DefinitionThe following are the normal steps for a LCA.Goal and Scope definitionInventory analysisImpact assessmentInterpretation habitatImpact assessment: An impact analysis “aims to examine the product system from an environmental perspective using impact categories and category indicators connected with the [inventory analysis’] results. The [impact assessment] phase also provides information for the life cycle interpretation phase.” (ISO 14042)130
131 Impact Modeling Environmental Fate and Risk Assessment Tool (EFRAT) Developed by Michigan Technological Institute Department of Chemical EngineeringModel basissimulation outputpreprogrammed chemical and soil propertiesEvaluates8 environmental indicesSafety factorsEconomic factors131
132 Environmental Indices IGW – global warmingISF – smog formationIOD – ozone depletionIAR – acid rainIINH – human inhalationIING – ingestion toxicityICINH -human carcinogenic inhalationICING – carcinogenic ingestion toxicityIFT – fish toxicityIXXGlobal Warming- indicates the potential to increase earths insulation layer resulting in higher global temperaturesSmog Formation- Indicates the potential to create smog. NOXs highly impact this indexOzone Depletion- Indicator of the potential for ozone depletion. Such compounds as Freon impact this index greatlyAcid Rain- The potential for the process to make the moisture in the atmosphere acidic. This moisture is then released as rain.Human Inhalation- Indicates the potential for causing respiratory problems in humansIngestion Toxicity- Indicates the potential for harmful ingestion to occurHuman Carcinogenic Inhalation- Indicate the risk associated with inhaling carcinogenic matterCarcinogenic ingestion toxicity- Indicates the risk of ingesting carcinogenic materailsFish Toxicity- indicates the potential for pollutants to affect fish132
133 Environmental Indices (Kg/L EtOH) Fish ToxicityIngestion ToxicityHuman Inhalationcarcinogenic ingestion toxicityHuman Carcinogenic InhalationGlobal WarmingSmog FormationAcid RainUpper Michigan Timberpremfg process a3.83E-061.52E-070.1291.83E-116.1E-130.5261.85E-053.59E-03mfg process2.3226.10.415-0.336.66E-043.46E-02total (kg/L EtOH)0.5420.1966.68E-042.82E-02Newsprintpremfg processb3.20E-061.65E-070.1192.42E-118.08E-130.4781.78E-053.36E-031.0226.90.4330.2915.44E-043.09E-020.5520.7695.60E-043.43E-02a Impacts from producing chemicals used in the ethanol process, for felling, skidding, and transportation of timber and of chipping.b Impacts from producing chemicals used in the ethanol process, of transportation of newsprint, and of pulpingOzone depletion is not examined in this study.Note: Global warming index for timber is negative in the manufacturing process. This results from providing electricity to the grid offsetting electricity made elsewhere with non renewable sources such as coal.These values are non weighted and on a per liter basis.Both the remanufacturing and the manufacturing processes contribute significantly to many of the indices133
134 Normalized Environmental Indices Each environmental index is multiplied by a weighting factorThe sum of all weighted indices=IL-CC – life cycle composite indexLife cycle composite index gives an overall value to process impactsWeighting factors used are determined by the group or individual performing the assessment. Therefore, the weighted values can be subjective and may vary from study to study. It is essential that non-weighted values are shown in order to maintain a state of transparency.IGW – global warmingISF – smog formationIOD – ozone depletionIAR – Acid RainIINH – human inhalationIING – ingestion toxicityICINH -human carcinogenic inhalationICING – carcinogenic ingestion toxicityIFT – fish toxicity134
135 Normalized and Weighted Environmental Indices (Kg/L EtOH) Higher Weighting FactorUpper MITimberNewsprint(Kg/L)IndexWeighted IndexWeighting FactorICINH6.10E-131.45E-182.4E-068.08E-131.93E-18ICING1.83E-114.33E-172.42E-115.70E-17IFT2.321.78E-087.7E-091.027.85E-09IING26.11.01E-073.8E-0926.91.04E-07IINH0.5422.09E-090.5522.13E-09IAR3.83E-022.12E-115.5E-103.43E-021.91E-11ISF6.68E-048.80E-141.3E-105.60E-047.40E-14IGW0.1968.93E-144.6E-130.7692.49E-13IL-CCMI Timber1.21E-07 Newsprint1.14E-7Here are all the indices weighted, non-weighted, and the weighting factors. The indices are arranged with the one with highest weighting factor at the top to the lowest at the bottom of the table.The sum of all these indices yields a life cycle composite index (IL_CC)The Yellow Poplar process has a higher overall LL_CCThe two processes differ most in the fish toxicity and global warming indices.Human ingestion toxicity contributes 83% and 91% to the LL_CC for Yellow Poplar and newsprint, respectively.Yellow Poplar process has more hemicellulose to convert to acetic acid resulting in a higher IFT valueNewsprint requires outside energy which results in a higher IINH .Newsprint process has about 6% lower life cycle composite index.Lower Weighting Factor135
136 Life Cycle Assessment -applied to cellulosic ethanol InterpretationImpact AssessmentInventory AnalysisGoal and Scope DefinitionThe LCI data require interpretationInterpretation: “The objectives of life cycle interpretation are to analyze results, reach conclusions, explain limitations and providerecommendations based on the findings of the preceding phases of the LCA or LCI study and to report the resultsof the life cycle interpretation in a transparent manner.” (ISO 14043)136
137 Life Cycle Improvement Analysis Process improvements to reduce emissionsCellulase seed reactor vent recycle streamCellulase seed reactor vent stream as combustion airIn the interpretation process modifications to the process are analyzed to determine the effects on the 8 environmental indices.137
138 Life Cycle Improvement Analysis Seed Reactor Recycle Stream Recycle 75% of Cellulase seed reactor vent back to the Cellulase seed reactorRecycle stream already at operating pressureRecycle stream contains 90% of required O2 concentrationYellow Poplar4.8% reduction of compressed air7.5 % reduction in total utilities2.2% reduction in IL-CCNewsprint50% reduction in compressed air8.6% reduction in utility consumption6.4% increase in IL-CCIn the newsprint process, the recycle stream does reduce compressed air and utility consumption but does not result in a lower IL-CC. Ethanol is recycled back to the seed reactor instead of escaping through the vent . From the seed reactor, this ethanol diffuses into the fermentation media and travels through the distillation and evaporation processes. Finally, the excess ethanol is carried to the pretreatment process in process water. In the pretreatment an increase in ethanol emissions offsets the reduction in utilities.1138
139 Life Cycle Improvement Analysis Seed Reactor vent stream recycle Indices compared to original processYellow PoplarAll indices decreasedLess volatile organic compounds releasedNewsprintIncrease in IFT, IING, and ISFDecrease in IGW and IARThis table shows the impacts of the recycle loop on all eight indices. The largest changes occur in the timber smog formation and newsprint global warming indices.139
140 Life Cycle Improvement Analysis Seed Reactor vent stream as combustion air Volatile Organic Compounds (VOC) from the seed reactor are combusted and used for energyYellow Poplar0.4% utilities reduction20% decrease in ISF, and IING2.7% reduction in IL-CCNews Print2.1% utilities reduction18.0% reduction in IL-CC140
141 Life Cycle Improvement Analysis Seed Reactor vent stream as combustion air Indices compared to original processThe smog formation indices decrease significantly as a result of utilizing the heating value of ethanol to offset natural gas usageReduction in the ingestion index also results from less ethanol in the vent stream141
142 Life Cycle Assessment Conclusions NewsprintProsLess fossil fuel required in pre-manufacturingLower ecotoxicityLower overall IL-CCConsManufacturing process is not energy self sufficientHigher index for IING, IINH, ICING, ICINH, and IGWYellow Poplar TimberManufacturing process is self sufficient and exports electricity to the gridLower global warming indexLower impacts to human healthMore fossil fuel required in pre-manufacturingHigher ecotoxicityHigher overall IL-CC142
143 Life Cycle Assessment Conclusions Main chemical contributors to indicesacetic acidCarbon monoxideEthanolFossil fuel energy required to produce transportation fuelYellow Poplar (ethanol)- 14% of energy contentNewsprint (ethanol)- 27% of energy contentPetroleum (gasoline/diesel)- 20% additional energy neededFuture WorkImpacts of large scale timber harvesting need to be examineAdditional studies comparing biomass-to-ethanol facilities to petroleum refineries needed to evaluate local health impacts1143
144 LCA Overall Review What you learned how to Define the goals and scope of a LCAPerform inventory analysisPerform an impact assessmentExamples reviewedCopy paper case studyBuilding material case studyBioethanol case study144
145 Copy Paper Case Study Review The Recycling scenario has the smallest carbon footprintLandfill carbon footprint is highly dependent on the methane recovery rateIncreased recycling may reduce green house gas emissionsIncreased recycling may impact the wood marketThese impacts are outside the scope of the study145
146 Housing Case Study Review Atlanta houseWood-512 GJ embodied energyConcrete-573 GJ embodied energy26% higher emissions120% higher emissions when including carbon sequesteredMinneapolis727 GJ embodied energySteel frame-840 GJ embodied energy31% higher emissions156% higher emissions when including carbon sequestered146
147 LCA Overall ReviewLCA has a great potential to help decrease the impacts of industrial processesLCAs can be a powerful marketing toolLCA can be an effective means to quantify and minimize emissionsLCA may become increasingly important with the introduction of carbon credits147
148 ReferencesEnergy Information Administration, Petrolium basic statistics;Kelly, Stephen; Forest Biorefineries: Reality, Hype or Something in Between?; Paper Age, March 2006;Kemppainen, Amber; Shonnard, David; Comparative Life-Cycle Assessment for Biomass-to-Ethanol Production from Different Regional Feedstocks; Department of Chemical Engineering, Michigan Technological University; Biotechnol. Prog. 2005, 21,Wooley, R.; Ruth, M.; Sheehan, J.; Ibsen, K.; Majdeski, H.; Galvez. A. Lignocellulosic Biomass to Ethanol Process Design and Economics Utilizing Co-Current Dilute Acid Prehydrolysis and Enzymatic Hydrolysis Current and Future Scenarios; National Renewable Energy Laboratory, NREL/TP , July 1999