Environmental Life Cycle Assessment

Environmental Life Cycle Assessment
Firoz Jameel, Jesse Daystar and Richard A. Venditti* Department of Wood and Paper Science North Carolina State University Raleigh, NC *Corresponding author: (919)

Introduction Learning Objectives of this section:
Be able to define a LCA To understand an LCA’s importance To identify important aspects of an LCA This is the introduction

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.

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 LCA Cradle 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 goods 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. 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.

Example LCA Process Production Use Disposal Recycle Raw Materials
Transportation Use Disposal Recycle Energy Waste Emissions to air and water Recycled Materials Raw Materials The unit processes for each LCA can vary. Often times there will be transportation between each unit process but this is not always the case.

Why is an LCA Important? Helps ensure compliance with government regulations Helps decrease the environmental impact of a given product Identifies ways to improve sustainability Identifies ways to “green” all aspects of product’s life Can reshape company strategy Can help marketing Can reshape company image Develop product advantage of competition An 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

Important Aspects of Life Cycle Assessment
Interpretation Impact Assessment Inventory Analysis Goal and Scope Definition The 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 category indicators connected with the [inventory analysis’] results. The [impact assessment] phase also provides information for the life cycle interpretation phase.” (ISO 14042) Interpretation: “The objectives of life cycle interpretation are to analyze results, reach conclusions, explain limitations and provide recommendations based on the findings of the preceding phases of the LCA or LCI study and to report the results of the life cycle interpretation in a transparent manner.” (ISO 14043)

Goal and Scope Definition
Learning Objectives of this section: To understand how to properly define the goals of an LCA To understand how to establish the boundaries of an LCA The purpose of this section is to explain how to establish the goals and the scope of an LCA

Defining Goals Should state the intent of the study
Intended application Intended use Intended audience Should also include reason for the study First, 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.

Defining Scope Define functional unit of product
Help establish system boundaries for the LCA Determine data collection methods When 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.

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 sandwich You’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 & Intent Intended Application: To inform the Wake County Public School food purchasers of the environmental impact of a PB&J Intended Use: To determine the global environmental impacts of serving a PB&J for Wake County Public Schools Intended Audience: Wake County Public School food system Scope System 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, product Analysis ends with the food being ingested by a person.

Interpretation Impact Assessment Inventory Analysis Goal and Scope Definition The 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

Inventory Analysis Learning Objectives of this section:
To understand what needs to be included in an inventory analysis To understand the steps and processes included in an inventory analysis 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.

Inventory Analysis: What Needs to be Included?
All relevant stages of the life of a product Raw Materials/Energy Needs Manufacturing Transportation, Storage & Distribution Use, reuse, and maintenance Recycle & Waste Management Production Transportation Use Disposal Recycle Energy Waste Emissions to air and water Recycled Materials Raw Materials An 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.

Inventory Analysis: Setup
In an LCA, it is necessary to standardize all units of measure For measuring energy use Use mega joules (MJ) to measure potential energy from non-renewable sources Use kilowatt hours (kW-h) to measure electrical energy For measuring waste materials and emissions Use tons to measure airborne emissions and solid waste Use gallons or liters to measure waterborne emissions Create a standard basis for comparison Example: per product piece, or per kg of product Establish rigid boundaries for the Inventory Analysis

Inventory Analysis: Raw Materials & Energy Needs
Two types of Raw Materials Primary- first use material Secondary- second use material (recycled) Analyze energy requirements Energy required to harvest the raw materials Energy required to convert the raw materials to the finished product Look at materials associated with maintaining the raw materials Define and quantify emissions and wastes associated with the production of the raw materials If 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.

Inventory Analysis: Manufacturing
Manufacturing should take into account the following Tools Molds, machinery, etc. Processes Waste Material Packaging All emissions produced Energy used When 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.

Inventory Analysis: Transportation, Storage and Distribution
Equipment used to move goods Airplanes, trucks, trains, etc Distance Storage and Distribution Warehouses Wholesalers Retailers For 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.

Inventory Analysis: Use, Reuse and Maintenance
Inventory or materials and energy required to fully utilize the product Use Energy required for normal use Emissions from normal use of the product Reuse Reusing product for the intended purpose Reusing the product in a different manner Maintenance Replacement parts Maintenance fluids Oils, grease, polish, paint, etc gasoline CO2, H2O motor oil, oil & air filter, hoses, tires, etc. spent motor oil, oil & air filter, hoses, tires, etc. spare parts for newer cars To 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.

Inventory Analysis: Recycle and Waste Management
Salvage of useful parts Production of secondary raw materials Waste Management Disposal of non-salvageable product Landfills, hazardous waste dumps, etc Incineration Composting To 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.

Inventory Analysis: Types of Pollution
Three main types of pollution Airborne emissions Carbon dioxide, sulfur dioxide, etc Waterborne emissions Wastewater, untreated chemicals, etc Solid waste Scrap materials, process waste, etc Throughout 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.

Inventory Analysis: ISO Standard
Overall steps for LCA are defined in ISO 14044 Steps for conducting an inventory analysis are explained in ISO 14041 Steps involved Preparing for data collection Data collection Validation of data Relating data to unit process Relating data to functional unit and data aggregation Refining system boundaries Proper 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.

Inventory Analysis: Example
Example product: copy paper Raw Materials Wood, water, various chemicals, energy Chemical and Energy Recovery Manufacturing Machinery, processes, packaging material Transportation and Distribution Storage of paper in warehouses, selling of it via wholesalers/retailers Use Products associated with the use of copy paper Disposal Waste products, Recycling, landfilling Energy recovery In 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.

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, oils Jelly: sugar, fruit, coloring Bread: flower, butter, preservatives Process raw materials: water, energy Manufacturing: Machinery, processes, packaging material, waste disposal Transportation: transporting raw materials, finished goods to warehouse, goods from warehouse to store, store to consumer end use location Use: Products associated with use of PB&J, ex. Napkin, knife Processes Raw material farming Transportation Raw material acquisition Product Manufacturing Use Waste management Process Inputs & Outputs Inputs Ingredients & materials Energy Water Outputs: Emissions Effluents Solid wastes Other releases Products Co-products

Interpretation Impact Assessment Inventory Analysis Goal and Scope Definition The 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 category indicators connected with the [inventory analysis’] results. The [impact assessment] phase also provides information for the life cycle interpretation phase.” (ISO 14042) 25

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 assessment To identify the usual steps and processes included in an impact assessment Impact 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.

Impact Assessment: ISO Standard
Overall steps for LCA are defined in ISO 14044 Protocol for an impact assessment is explained in ISO 14042 Mandatory elements for an impact assessment Selection of impact categories Assignment of inventory analysis results Calculation of category indicator results (characterization) Optional elements Calculation of the magnitude of category indicators (normalization) Grouping Weighting To 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.

Impact Assessment: What Needs to be Included?
All environmental impacts associated with the production, use and disposal of the product Ecological Systems Degradation Resource Depletion Human Health & Welfare Add 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 region Human Health & Welfare: the health and welfare of people living in surrounding areas to production facilities or raw material acquisition sites.

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) Chemical Toxicity Physical Habitat Loss Biological Foreign Species For 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

Impact Assessment: Ecological Systems Degradation – Risks Assessment
F Cl Freon 11 Ecological Response to Indicator Intensity of Potential Effect Time Scale of Recovery Spatial Scale Transport Media There is no global agreement in weighting risks Hole in ozone layer caused by Freon To 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).

Impact Assessment: Resource Depletion
Resources are either renewable or non-renewable Renewable Hydroelectric energy, biomass products, most crops, etc Non-renewable Oil, minerals, metals, etc Ideally want to recycle as many non-renewable based components as possible The 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.

Impact Assessment: Human Health & Welfare
Analyze impact of product on human health Diseases that could potentially be caused by using the product Cigarettes: Cancer Diseases that can be caused by wastes produced by the product or the production of it Solid particulates emitted in stack gasses for a coal burning plant: Cancer Products that harm human health can have a negative impact on a company’s image Finally, 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.

Environmental Indices
IGW – global warming ISF – smog formation IOD – ozone depletion IAR – acid rain IINH – human inhalation IING – ingestion toxicity ICINH -human carcinogenic inhalation ICING – carcinogenic ingestion toxicity IFT – fish toxicity IXX Global Warming- indicates the potential to increase earths insulation layer resulting in higher global temperatures Smog Formation- Indicates the potential to create smog. NOXs highly impact this index Ozone Depletion- Indicator of the potential for ozone depletion. Such compounds as Freon impact this index greatly Acid 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 humans Ingestion Toxicity- Indicates the potential for harmful ingestion to occur Human Carcinogenic Inhalation- Indicate the risk associated with inhaling carcinogenic matter Carcinogenic ingestion toxicity- Indicates the risk of ingesting carcinogenic materails Fish Toxicity- indicates the potential for pollutants to affect fish 33

Impact Assessment: Example
Example product: copy paper Ecological systems degradation Impact of cutting down trees Impact of discharged chemicals in the water waste on the water quality Resource depletion Resource is renewable because it is trees, but it is not rapidly replaceable The paper is easily recyclable, reducing primary raw material needed For energy, mostly self sufficient Human health and welfare Impact of chemicals used on human health Impact of stack emissions from chemical and energy recovery on health of population around mill Once 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.

Impact Assessment: Your Turn
Exercise: Conduct the impact assessment for a Peanut Butter and Jelly Sandwich Examine: Ecological system degradation 1. impact of fertilizer runoff 2. deforestation for farm land Resource Depletion 1. energy resources such as oil or coal 2. impact of the soil nutrient depletion Human Health and Welfare 1. health impacts of fertilizers used on humans due to ingestion 2 health impacts of air pollutants due to peanut processing and transportation such as CO2

Interpretation Impact Assessment Inventory Analysis Goal and Scope Definition The following are the normal steps for a LCA. Interpretation: “The objectives of life cycle interpretation are to analyze results, reach conclusions, explain limitations and provide recommendations based on the findings of the preceding phases of the LCA or LCI study and to report the results of the life cycle interpretation in a transparent manner.” (ISO 14043) 36

Interpretation Learning Objectives of this section:
To be able to identify what needs to be included in an interpretation To understand how this step can be best used Interpretation: the stage at which the analyst deduces potential ways to make the process more environmentally friendly

Interpretation: ISO Standard
Overall steps for LCA are defined in ISO 14044 Proper protocol for interpretation is explained in ISO 14043 Aside from presenting results, the interpretation should conduct these checks Completeness check Sensitivity check Consistency check Include conclusions and recommendations The 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.

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 improvement Changes in product design Changes in raw material usage Changes in industrial processes Original product After Improvement Analysis The 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.

Interpretation: Example
Example product: copy paper Changes in product design Determining potential areas of improvement for the product design Lighter weight paper? Lower brightness paper? Changes in raw materials Using more secondary materials in place of primary materials Use alternative chemicals Changes in industrial process Changing from Acid to Alkaline papermaking Changing from chlorine containing bleaching processes to chlorine free bleaching processes Once 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.

Interpretation: Your Turn
Exercise: Interpret the results of your LCA and present them to the group Significant issues: Much of the impact of a PB&J comes from the transportation of the products. Examine for completeness Recommendations Raw Material analyze higher yielding peanut strands Packaging use more environmentally friendly packaging Manufacturing Modify process to increase energy efficiency

Carbon Footprint Model
for Bleached Pulp and Paper Products Trevor H. Treasure, Jesse S. Daystar and Richard A. Venditti* Department of Wood and Paper Science North Carolina State University Raleigh, NC *Corresponding author: (919) 42

Waste Paper What do we do with it all?
More than 700 lb/person annual paper consumption in the USA 40% of all municipal waste is paper What 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 footprint 43

Life Cycle Assessment -Recycling Paper Products
Interpretation Impact Assessment Inventory Analysis Goal and Scope Definition The following study is not a complete life cycle analysis. It only considers greenhouse gasses and does not include an impact assessment around these emissions Goal and Scope definition: Identifies the intended purpose of the LCA and determines what items shall be considered. 44

Goals To compare the carbon footprint of three waste management scenarios for copy paper 1. Landfilling 2. Incineration 3. Recycling To perform a systematic and quantitative evaluation of these three waste management options To provide a tool for consumers and waste management personnel for determining the best waste management practices The 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

Three waste management scenarios considered. Landfilling Incinerating Recycling This study will not consider the effect of recycling on the value of wood or its consequences on the wood market A full impact assessment will not be performed This analysis only accounts for carbon emissions Other significant pollutants are emitted but are not accounted for in this study, example heavy metals 46

Assumptions 1 of 2 Increased recycle production has no effect on tree production Methane 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 grid Heating value of copy paper  6213 BTU/lb (PTF White Paper No.3) Net heating value of methane 21,433 BTU/lb (engineeringtoolbox.com) 47

Assumptions 2 of 2 Responsible silviculture  replant to harvest ratio equals 1:1 Carbon sequestration based on wood makeup and weight percent carbon of cellulose, hemicelluloses, and lignin All mills are considered to be average in energy and production efficiency Office paper is assumed to be 20% inert, inorganic filler material Office paper fibers: 20% softwood and 80% hardwood 48

Life Cycle Assessment -recycling paper products
Interpretation Impact Assessment Inventory Analysis Goal and Scope Definition 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. 49

Raw Material Composition
Paper Composition % % Soft Wood 20% % Hard Wood 80% Component Softwood Hardwood Cellulose 42% 45% Hemicellulose 27% 30% Lignin 31% 25% Component % carbon by weight Major Hemicellulose - SW 44.68% Minor Hemicellulose - SW 47.31% Major Hemicellulose - HW 37.76% Minor Hemicellulose - HW 43.60% Lignin 60.93% 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 332 50

Carbon Equivalents Carbon Equivalents Conversion ` CO2 Tons
12 g carbon/mol =Carbon Equivalents 44 g CO2/mol Methane Tons 12 g carbon/mol =Carbon Equivalents 16 g CH4/mol 12+(4x1)=16 Methane Tons combusted 12 g carbon/mol =Carbon Equivalents 16 g CH4/mol 51

Process Flow Diagram 1 of 2 Virgin Production + Landfilling
Energy/fuel CO2 Emissions Energy/fuel CO2 Emissions Filler The 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 stack Co2 sign Coal Train Gas Pump Energy/fuel CO2 Emissions 52

Process Flow Diagram 1 of 2
Energy/fuel=0 CO2 Emissions=0 CO2 Emissions Energy/fuel Energy/fuel CO2 Emissions Methane Emissions When 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 landfill Electricity production 53

Process Conversions 1 ton methane is equal to 21 ton CO2 equivalents
lb CO2 Per ton Source Green Wood Transportation 305 Green wood Paper Task Force White Paper Virgin Production 2995 Paper Transportation to Market 33 Collection and Landfill Equipment 84 Landfill % by wieght Source CO2 Landfill Emmisions 15.2% Paper task force white papers Methane Landfill Emissions 22.9% Carbon Sequestured 61.9% Mathane Recovered 50.0% Assume 50% (CORRIM) CO2 from Methane Combustion 75.0% Carbon Offset from Electrical Production Source CO2 Offset from Electrical Production 127 CO2 lbs per MMBTU Paper Task Force White Paper Net BTU 21433 BTU per lb Methane Engineering Tool Box 1 ton methane is equal to 21 ton CO2 equivalents 54

Virgin Production + Landfill Energy Requirements and Carbon Emissions
MMBTU UNIT PROCESS Emissions Ton Carbon Equivalents Tree Growth -791 1909 Tree Harvest and Transport 139 37913 Paper Mill 1418 205 Paper Transport to Market 4.5 ~0 Use of Product 527 Collection Vehicle & Landfill Equipment 11.5 -1863 Landfill 30.5 38690 Total 812 Negative values represent either energy created or carbon sequestered 55

Process Flow Diagram 1 of 2 Virgin Production + Incineration
CO2 Emissions Energy/fuel Energy/fuel CO2 Emissions The first part of this process is identical to the landfill scenario. Each unit process uses energy and has a corresponding CO2 emissions. smoke stack Co2 sign Coal Train Gas Pump Energy/fuel CO2 Emissions 56

Process Flow Diagram 2 of 2
Energy/fuel=0 CO2 Emissions=0 Energy/fuel CO2 Emissions Energy/fuel CO2 Emissions This 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 Emissions Methane Emissions Carbon 57

Virgin Production + Incineration Calculations
Incinerator carbon equivalents emissions= tons carbon in wood Virgin paper mill yield % Fiber in paper Energy produced from paper combustion= tons paper tons virgin production 6213 BTU 2000 lbs lb paper ton 1,000,000 BTU 1 MMBTU White paper #3 Incinerator carbon equivalents emissions Carbon in wood X PM Yield% X %fiber in paper Energy produced from paper combustion Tons paper*6213btu/lb paper1*2000/1,000,000 Landfill ash Equal to the filler content 58

Ton Carbon Equivalents
Virgin Production + Incinerate Energy Requirements and Carbon Emissions Energy MMBTU UNIT PROCESS Emissions Ton Carbon Equivalents Tree Growth -791 1909 Tree Harvest and Transport 138.6 37913 Paper Mill 1418 205 Paper Transport to Market 4.5 ~0 Use of Product 0.0 297 Collection Vehicle & Landfill Equipment 6.5 -11643 Incineration 89.0 28680 Total 866 Units Negative values represent either energy created or carbon sequestered 59

Process Flow Diagram 1 of 3 Recycled Production + Recycling
Energy/fuel CO2 Emissions Energy/fuel CO2 Emissions Energy/fuel CO2 Emissions The 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/fuel CO2 Emissions Filler Rejects to waste treatment 60

Energy/fuel CO2 Emissions Energy/fuel=0 Carbon sequestered in product Possible decrease in demand One 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 study Forest used in more profitable ways such as construction 61

Energy/fuel CO2 Emissions CO2 Emissions Methane Emissions Since 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 paper 62

Recycled Production + Recycle
Calculations Recycled Production + Recycle Carbon sequestered in use= tons carbon in wood Tons virgin production Virgin paper mill yield % Tons recycled paper tons organics Filler content (1-.382) Carbon sequestered in landfill= Paper Task Force: White Papers Tons organics in sludge= Tons recycled paper % Filler Total sludge 63

Recycled Production + Recycle Energy Requirements and Carbon Emissions
MMBTU UNIT PROCESS Emissions Ton Carbon Equivalents 989 Recovered Paper Collection 26.5 283 Material Recovery Facility 5.3 205 Transport to Recycle Mil 6 20300 Recycle Paper Mill 470 Transportation to Market 4.5 Use -380 227 Collection Vehicle and Landfill Equipment 4.9 -1133 Landfill 19 21077 Total 156.1 Negative values represent either energy created or carbon sequestered 64

Unit Process Emissions
All values are tons Virgin Prod. + Landfill Virgin Prod. + Incinerate Recycle Prod. + Recycle Carbon sequestered in tree growth -791 N/A Raw material acquisition 139 37.3 Paper mill production 1418 470 Transport to market 4.5 Carbon sequestered in product -395 Collection and landfill equipment/ sorting 11 6 4.9 Landfill 265.1 0.0 161 Carbon sequestered in landfill -235 -143 Incinerate 89 Total Carbon Equivalents 812 866 141 Total Carbon Equivalents per ton 0.812 0.866 0.141 Note: Negative values represent carbon sequestered The recycling paper mill process emits much less carbon equivalents than the other two options CO2 emissions for recycling production are much less than virgin production Carbon sequestered in the recycling process is sequestered in the product. For virgin production it is accounted for in the growing of trees CO2 emissions for landfilling are much less in the recycling process Landfilling (emissions-credits) 65

% Difference From Landfilling
Carbon Equivalents Emissions Comparison % Difference from Landfilling Landfill reported in tons for comparison Virgin Prod. + Landfill Virgin Prod. + Incinerate Recycle Prod. + Recycle Raw material acquisition 139 0% -73% Paper mill production 1418 -67% Collection and landfill equipment/ sorting 11 -44% -57% Landfill 265 -100% -39% Carbon sequestered in landfill -235 Total Carbon Equivalents 812 7% -83% Total Carbon Equivalents per ton 0.812 This 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 incineration The 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

Sensitivity Analysis Virgin Production + Landfill
Sensitivity Analysis on Carbon Equivalents per ton for Virgin Production + Landfill Percent Change 10% -10% % Change from base Case Softwood % 0.808 0.817 0.58% Transportation emissions 0.828 0.797 1.90% Landfill methane recovery 0.763 0.862 6.12% Base case value of .812 carbon equivalents per ton of production Landfill methane recovery rate has the largest impact on carbon emissions Methane is 21 times more harmful than CO2 A sensitivity analysis illustrates the effects different process parameters have on the total carbon equivalents per ton Here 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

Sensitivity Analysis Virgin Production +Incinerate
Sensitivity Analysis on Carbon Equivalents per ton for Virgin Production + Incinerate Percent Change 10% -10% % Change from base Case Softwood % 0.863 0.869 0.35% Transportation emissions 0.881 0.851 1.73% Landfill methane recovery 0.866 0.00% Base case value of .866 carbon equivalents per ton of production The carbon emissions of this waste management practice are not greatly impacted by these sensitivities The virgin production and incineration option was less sensitive to these parameters Transportation was sensitivity had the largest impact in this management option. 68

Sensitivity Analysis Recycled Production + Recycling
Sensitivity Analysis on Carbon Equivalents per ton for Recycled Production + Recycle Percent Change 10% -10% % Change from base Case Softwood % 0.141 0.00% Transportation emissions 0.145 0.136 2.95% Landfill methane recovery 0.110 0.171 21.50% Base case value of .141 carbon equivalents per ton of production Landfill methane recovery rate has the largest impact on carbon emissions Transportation emissions significantly impacted the total For 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

ton C produced/ton paper
Interpretation Waste Management Method ton C produced/ton paper Virgin Production + Landfill 0.650 Virgin Production + Incinerate 0.725 Recycle Production + Recycle 0.207 The Recycling scenario has the smallest carbon footprint Landfill carbon footprint is highly dependent on the methane recovery rate Increased recycling may reduce green house gas emissions Increased recycling may impact the wood market These impacts are outside the scope of this study 70

Interpretation: Environmental Improvement Opportunities
Potential Process Improvement Increase methane recovery in landfills Decrease transportation of products and raw materials Increase paper production efficiency Energy Use renewable transportation fuels Utilize renewable electrical power Increase energy efficiency in production process 71

Wood for Building Houses An Example of LCA
Adam Taylor Assistant Professor Forestry, Wildlife & Fisheries 203 Forestry Products, 2506 Jacob Drive Knoxville, TN 37996 Phone: 72

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

Acknowledgment All of the information in this presentation is based on work conducted by CORRIM 74

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 materials The 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

Motivation The environmental consequences of changes in forest management, product manufacturing, and construction are poorly understood 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 Motivation 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

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 review Mission: 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 review 77

Membership in CORRIM Research Institutions and Voting Board Members
University of Washington Oregon State University University of Minnesota University of Idaho FORINTEK, Canada Virginia Tech North Carolina State University Purdue University University of Maine Penn State University State University of New York APA, The Engineered Wood Association Western Wood Products Association Composite Panel Association Research Foundation Washington State University Louisiana State University Mississippi State University 78

Life Cycle Assessment -applied to building products
Interpretation Impact Assessment Inventory Analysis Goal and Scope Definition The following are the normal steps for a LCA. Goal and Scope definition Inventory analysis Impact assessment Interpretation Goal and Scope definition: Identifies the intended purpose of the LCA and determines what items shall be considered. 79

Goals To develop a database and modeling system for environmental performance measurements associated with materials use To 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

Scope Houses built with different materials
Minneapolis (cold climate) - wood & steel Atlanta (warm climate) - wood & concrete 81

Minneapolis House – Front Elevation
82

Design Differences: Minneapolis
Full Basement 2062 sq.ft. 2 story Characteristic Wood Design Steel Design 1st and 2nd Floors Engineered wood “I” 16” (400mm) o/c & 19/32” (15mm) plywood decking Steel 18 ga. “C” 12” (300mm) o/c & 19/32” (15mm) plywood decking Above grade exterior walls 2” x 6” wood 16” (400mm) o/c, #15 organic felt, OSB sheathing, R19 fiberglass batt insulation, 6mil polyethylene vapor barrier, 12mm gypsum board, vinyl siding 1.5” x 3.63” Steel 20 ga. “C” 16” (400mm) o/c, #15 organic felt, OSB sheathing, R13 fiberglass batt insulation, 1.5” EPS insulation, 6mil polyethylene vapor barrier, 12mm gypsum board, vinyl siding Below grade exterior walls 2”x4” wood 24” (600mm) o/c, R13 fiberglass batt insulation, poly vapor barrier, 12mm gypsum board 1.5” x 3.63” Steel 25 ga. “C” 24” (600mm) o/c, R13 fiberglass batt insulation, poly vapor barrier, 12mm gypsum board Partition walls 2”x4” wood 16” (400mm) o/c, 12mm gypsum board two sides 1.5” x 3.63” Steel 25 ga. “C” 16” (400mm) o/c, 12mm gypsum board two sides 83

Design Differences: Atlanta
2153 sq.ft. 1 story On-Slab Characteristic Wood Design Concrete Design Single-family dwelling type 1 story bungalow slab-on-grade Floor area 2153 sq. ft. (200 sq.m) Structure & Envelope Foundation (footing and slab) 3000psi (20 Mpa) concrete Foundation walls None Main floor 100mm reinforced Slab-on-grade on footings Exterior walls 2”x4” wood 16” (400mm) o/c, #15 organic felt, OSB sheathing, R13 fiberglass batt insulation, 6mil poly vapor barrier, 12mm gypsum board, vinyl siding Concrete Block furred out with 2x4 wood studs 24”(600mm) o/c, R13 fiberglass batt insulation, 6mil poly vapor barrier, 12mm gypsum board, two-coat stucco finish Window system PVC frame, operable, double glazed Low “E” Argon filled Partition walls 2”x4” wood 16” (400mm) o/c,12mm gypsum board two-sides Roof Light Frame Wood Trusses with OSB sheathing, R30 blown cellulose insulation, 6mil poly vapor barrier, 16mm gypsum board with 25 yr durability asphalt shingles over #15 organic felt building paper. 84

Interpretation Impact Assessment Inventory Analysis Goal and Scope Definition The following are the normal steps for a LCA. Goal and Scope definition Inventory analysis Impact assessment Interpretation 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. 85

Life Cycle Inventory Analysis for Wood Building Materials
Forest Management (Regeneration) (Transportation) EMISSIONS Raw Material Acquisition (Harvest) EFFLUENTS MATERIALS (Transportation) SOLID WASTES Product Manufacturing ENERGY (Transportation) OTHER RELEASES Collected 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 Construction WATER (Transportation) Use/Maintenance PRODUCTS (Transportation) COPRODUCTS Recycle/Waste Management (Transportation) 86

System Boundaries Forest Resources: NW and SE (25-100+ years)
Harvesting ( < 1 Year) logs NW and SE Processing ( < 1 Year) lumber SE and NW (green and dry) plywood NW and SE OSB SE Glulam, LVL, I-Joists Construction ( < 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

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 detail Multi-material detail Environmental Performance: Air, water, toxic substances, energy, carbon, waste mid-point parameters for human health risk Strategic Research Plan (1998) Study Guideline (2000) – ISO consistent Protocol: 88

Building Product LCI’s
For building products for lumber, plywood, OSB, LVL, glulam, I-joists, trusses Unit process descriptions (saw, dry, plane etc.) Mill surveys at unit process level Non-wood inputs (energy by source, raw materials) Emissions and solid waste outputs Yields, flows (co-products) and mass balances Unit factor estimates (raw materials, air, water, and solid emissions, energy, carbon) before and after impacts from purchased energy and transportation 89

U.S. LCI Database Project
ATHENA & NREL Publicly available info on common materials, products and processes Could lead to “eco-impact labels” similar to food labeling 90

Life-Cycle Inventory results 1.0 MSF 3/8-in. basis plywood production
INPUTS OUTPUTS Materials Units Per MSF Materials Units Per MSF 3/8-in. basis 3/8-in. basis Bark ft.3 6.56E+01 Bark waste Bark ash Total Products Plywood Co-products Wood chips Peeler core Green clippings Panel trim Sawdust Air emissions Acetaldehyde Acetone Acrolein Benzene CO CO 2 fossil Dust (PM10) Formaldehyde Methanol NO x Particulates Phenol SO 2 SO x lb. 1.31E+01 Wood/resin lb. 1.89E+03 7.75E+00 Roundwood (log) 2.09E+01 lb. 1.59E+01 Phenol-formaldehyde a lb. 8.90E+00 9.91E+02 Extender and fillers lb. 1.11E+00 4.25E+02 Catalyst a lb. 3.30E-01 4.62E+01 lb. 1.98E+02 3.10E+01 Soda ash a Veneer downfall 3.44E+00 Bark b lb. 6.81E+00 1.07E+02 Dry veneer lb. 1.51E+01 9.63E+00 Solid dry veneer 6.68E+01 Green veneer 6.89E+02 Electrical energy Electricity kWh 1.39E+02 1.12E-02 4.80E-03 Fuel for energy b 4.95E-07 Hog fuel (produced) b lb. 3.83E+02 4.77E-04 Results 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+00 Hog fuel (purchased) lb. 3.40E+01 2.78E+02 Wood waste lb. 5.00E-01 CO 2 non-fossil 2.78E+02 Liquid propane gas gal. 3.59E-01 2.08E-01 1.80E-02 Natural gas ft.3 1.63E+02 1.28E-01 Diesel gal. 3.95E-01 2.34E-01 Organic substances 2.20E-02 a These materials were excluded based on the 2% rule. 3.47E-01 8.27E-03 b Bark and hogged fuel are wet weights whereas 7.74E-04 all other wood materials are oven dry weights; 1.01E-01 bark weight is included in the “hog fuel (produced)” weight. VOC lb. 6.26E-01 91

Interpretation Impact Assessment Inventory Analysis Goal and Scope Definition The following are the normal steps for a LCA. Goal and Scope definition Inventory analysis Impact assessment Interpretation Impact 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

An example of LCI comparisons: Minneapolis
Steel minus Wood Extraction (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

An example of LCI comparisons : Atlanta
Concrete minus Wood Extraction (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 design 94

GWP: Minneapolis and Atlanta
Global Warming Potential Index CO2 Equivalence Effects: (CO2, N2O, CH4) 95

Summary - Minneapolis Building Other Design vs. Wood (% Change)
Minneapolis design Wood Steel Difference Other Design vs. Wood (% Change) Embodied Energy (GJ) 651 764 113 17% Global Warming Potential (CO2 kg) 37,047 46,826 9,779 26% Air Emission Index (index scale) 8,566 9,729 1,163 14% Water Emission Index (index scale) 17 70 53 312% Solid Waste (total kg) 13,766 13,641 -125 -1% 96

Summary - Atlanta Building Other Design vs. Wood (% Change)
Atlanta Design Wood Concrete Difference Other Design vs. Wood (% Change) Embodied Energy ( GJ) 398 461 63 16% Global Warming Potential (CO2 kg) 21,367 28,004 6,637 31% Air Emission Index (index scale) 4,893 6,007 1,114 23% Water Emission Index 7 0% Solid Waste (total kg) 7,442 11,269 3,827 51% 97

Other Studies – Same Results
1992 New Zealand study Wood office building 55% of energy/70% carbon versus concrete Steel wall 4x energy of wood wall 1992, 1993 Cdn studies Wood 1/3 energy and CO2 versus steel and concrete Wood consistently lower emissions and less energy 98

Interpretation Impact Assessment Inventory Analysis Goal and Scope Definition The LCI data require interpretation Interpretation: “The objectives of life cycle interpretation are to analyze results, reach conclusions, explain limitations and provide recommendations based on the findings of the preceding phases of the LCA or LCI study and to report the results of the life cycle interpretation in a transparent manner.” (ISO 14043) 99

Not All Energy is Equal Much 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

Emissions to Water: Minneapolis
Not all pollution is equal Worst offending toxin example Compare output to EPA acceptable limits for the pollutant. 101

Emissions to Water: Minneapolis On Equal Health Risk Basis
102

Energy in Building Life Cycle
Minneapolis House Atlanta House Wood Steel Concrete Structure (GJ) 646 759 395 456 Maintenance (GJ) 73 110 Demolition (GJ) 7 9 Embodied energy total (GJ) 727 840 512 573 75 years of heat & cooling energy (GJ) 7800 4575 Energy 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

Carbon Dynamics vs. Steady State
LCI provides a cross sectional profile of all processes -- a steady state analysis Tracking carbon pools over time offers a dynamic alternative for a more financial cost/benefit perspective LCA’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

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

Concrete frame/wood frame Atlanta
Steel frame /wood frame Minneapolis Steel frame/wood frame Minneapolis The 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

Carbon In Forest Pools Harvest rotation years FIA data on old stands
No harvest 44, 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 years 107

Carbon Dynamics Need to be Considered
Averages over time intervals CARBON DYNAMICS IN FORESTS, WOOD PRODUCTS AND (CONCRETE) SUBSTITUTES The ‘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

Carbon Emissions in Representative Building Life Cycle Stages
CO2 Minneapolis House Atlanta House Metric Tons Wood Steel Concrete Emissions in Mfg Construction & Demo 37.1 46.8 21.4 28.0 Emissions from Biofuel 3.6 2.6 3.4 2.7 Emissions from Maintenance 4.1 Emissions from Heating & Cooling 390 232 Subtotal of Sources 434 443 261 267 Forest 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) 185 140 167 109

Interpretation: Environmental Improvement Opportunities
Redesign the house use less fossil-intensive products (wood is good!) reduce energy use (both active and passive) improve durability to increase useful life Improve the product greater use of biofuel engineered products for greater raw materials efficiency increase process efficiencies, especially in drying pollution control improvements increase product durability Reduce, reuse and recycle demolition wastes 110

LCA Strengths & Weaknesses
Pro System wide Quality and objectivity Multiple impact factors Con Dependent on quality of LCI LCI difficult to establish Steady state Resources change Time value of money 111

Life Cycle Assessments
Biomass to Ethanol from Different Regional feedstocks Jesse Daystar, Richard Venditti* Based on work of Kemppainen and Shonnard Department of Wood and Paper Science North Carolina State University Raleigh, NC *Corresponding author: (919) 112

Biomass to Ethanol Potential ethanol production
U.S. Department of Agriculture Biomass Estimation Estimated 3.56 million dry tons on a sustainable basis in U.S. per day2 U.S. Oil Consumption 868.6 million gallons/day1 Potential ethanol production 9.58 million gallons per day of oil equivalents2 113

Life Cycle Assessment -applied to cellulosic ethanol
Interpretation Impact Assessment Inventory Analysis Goal and Scope Definition The following are the normal steps for a LCA. Goal and Scope definition Inventory analysis Impact assessment Interpretation Goal and Scope definition: Identifies the intended purpose of the LCA and determines what items shall be considered. 114

Goals To compare the environmental impacts of two processes that utilize different regional cellulosic feedstocks to produce ethanol. Yellow Poplar regional to Michigan Recycled Newsprint 115

Scope "Cradle to gate” Different from “cradle to grave”
Acquisition of raw material through production of ethanol Different from “cradle to grave” Will not investigate the impacts of the use of ethanol Why Cradle to Gate? End use of ethanol for both alternatives is identical Cradle Production Gate 116

Interpretation Impact Assessment Inventory Analysis Goal and Scope Definition The following are the normal steps for a LCA. Goal and Scope definition Inventory analysis Impact assessment Interpretation 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. 117

Simulation and Modeling Yellow Poplar
diesel & gasoline Felling & Skidding Chipping Ethanol Production Pre-manufacturing diesel Transportation electricity Raw material & energy Boustead Model Emissions Factors & EFRAT ASPEN Simulation & EFRAT The 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

Simulation and Modeling News Print
diesel & gasoline Collection & Sorting Pulping Ethanol Production Pre-manufacturing diesel Transportation electricity Raw material & energy Boustead Model Emissions Factors & EFRAT ASPEN Simulation & EFRAT Again 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

Feedstock Composition
% dry wt basis component Yellow Poplar(NREL)3 Yellow Poplar upper Michigan timber newsprint cellulose 42.6 49.15 63.77 xylan 19.05 16.89 5.26 arabinan 0.79 1.04 0.61 mannan 3.93 3.76 4.96 galactan 0.24 1.01 acetate 4.64 3.38 0.00 lignin 27.68 24.45 21.26 ash 1.00 0.31 3.54 moisture 47.9 68.4 5.0 The 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

Boustead Model Standard Data Sets Custom Data Sets
Transportation distances, materials used, utilities The 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 Results 121

NREL Process Modeling Modeling software ASPEN
Developed by M.I.T. and the Department of Energy Process modeling Process optimization ASPEN 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 Results 122

Pre-manufacturing Energy Usage
upper MI timber newsprint Kg/h MJ/h Premanufacturing, Chemicals ammonia 1,194 88,620 638 47,370 ammonium sulfate 108 2,216 169 3,376 antifoam 268 21,628 356 28,696 calcium phosphate 1,161 1,899 diesel 470 557 gasoline 938 1,088 978 1,134 lime 693 8,124 570 6,647 sulfuric acid 1,839 9,495 1,680 8,651 subtotal 132,889 97,773 Premanufacturing, Operations felling (gasoline) 21 1,688 skidding (diesel) 33 transportation (diesel) 157 6,752 232 9,917 chipping (gasoline) 12 633 pulping (electricity) 9,073 11,289 18,990 This 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 processes The 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

Simplified Process Flow
Ammonia, Lime, Acid Feed Handling Pretreatment (Detoxification) Hydrolysis & Fermentation Product & Water Recovery Ethanol Storage Waste Combustion Utilities Waste Water Treatment (Solid Separation) Cellulase Electricity Steam Feedstock Recycle water Enzyme Chips Sugars Recycle Water Nutrients Air Steam Excess Condensate This 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 reactors Pretreatment: This process converts the hemicelluloses to sugars Cellulase: This process uses sugars from the pretreatment in conjunction with other nutrients to grow the enzymes needed to hydrolyze the cellulose Hydrolysis and Fermentation (SSF): In this process enzymes break down cellulose into sugars then yeast ferments those sugars to produce alcohols Product 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 electricity Waste Water Treatment: Here process water is cleaned for further use and solid waste is processed Still Solids 124

Detailed Process Flow This is a more detailed flow diagram with mass flows and an energy balance. This process flow was made by Kemppainen and Shonnard. 125

Energy Balance Upper Michigan Timber
Process loses 9.7% of total energy through processes inefficiencies 30% of total energy consumed in cooling water system This is higher than newsprint due to higher boiler throughput Energy balance has an accuracy of 2%

Energy Balance News Print
2.2% more energy leaves with ethanol product for newsprint compared to timber process Energy 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.

Process Air Emissions Here 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.

LCA Progress So Far So far we have Defined scope
☐ So far we have Defined scope Defined goal/objective Performed inventory analysis Performed energy balance Next Impact assessment LCA interpretation LCA improvement   ☐ 129

Interpretation Impact Assessment Inventory Analysis Goal and Scope Definition The following are the normal steps for a LCA. Goal and Scope definition Inventory analysis Impact assessment Interpretation habitat Impact 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

Impact Modeling Environmental Fate and Risk Assessment Tool (EFRAT)
Developed by Michigan Technological Institute Department of Chemical Engineering Model basis simulation output preprogrammed chemical and soil properties Evaluates 8 environmental indices Safety factors Economic factors 131

Environmental Indices
IGW – global warming ISF – smog formation IOD – ozone depletion IAR – acid rain IINH – human inhalation IING – ingestion toxicity ICINH -human carcinogenic inhalation ICING – carcinogenic ingestion toxicity IFT – fish toxicity IXX Global Warming- indicates the potential to increase earths insulation layer resulting in higher global temperatures Smog Formation- Indicates the potential to create smog. NOXs highly impact this index Ozone Depletion- Indicator of the potential for ozone depletion. Such compounds as Freon impact this index greatly Acid 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 humans Ingestion Toxicity- Indicates the potential for harmful ingestion to occur Human Carcinogenic Inhalation- Indicate the risk associated with inhaling carcinogenic matter Carcinogenic ingestion toxicity- Indicates the risk of ingesting carcinogenic materails Fish Toxicity- indicates the potential for pollutants to affect fish 132

Environmental Indices (Kg/L EtOH)
Fish Toxicity Ingestion Toxicity Human Inhalation carcinogenic ingestion toxicity Human Carcinogenic Inhalation Global Warming Smog Formation Acid Rain Upper Michigan Timber premfg process a 3.83E-06 1.52E-07 0.129 1.83E-11 6.1E-13 0.526 1.85E-05 3.59E-03 mfg process 2.32 26.1 0.415 -0.33 6.66E-04 3.46E-02 total (kg/L EtOH) 0.542 0.196 6.68E-04 2.82E-02 Newsprint premfg processb 3.20E-06 1.65E-07 0.119 2.42E-11 8.08E-13 0.478 1.78E-05 3.36E-03 1.02 26.9 0.433 0.291 5.44E-04 3.09E-02 0.552 0.769 5.60E-04 3.43E-02 a 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 pulping Ozone 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 indices 133

Normalized Environmental Indices
Each environmental index is multiplied by a weighting factor The sum of all weighted indices= IL-CC – life cycle composite index Life cycle composite index gives an overall value to process impacts Weighting 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 warming ISF – smog formation IOD – ozone depletion IAR – Acid Rain IINH – human inhalation IING – ingestion toxicity ICINH -human carcinogenic inhalation ICING – carcinogenic ingestion toxicity IFT – fish toxicity 134

Normalized and Weighted Environmental Indices (Kg/L EtOH)
Higher Weighting Factor Upper MI Timber Newsprint (Kg/L) Index Weighted Index Weighting Factor ICINH 6.10E-13 1.45E-18 2.4E-06 8.08E-13 1.93E-18 ICING 1.83E-11 4.33E-17 2.42E-11 5.70E-17 IFT 2.32 1.78E-08 7.7E-09 1.02 7.85E-09 IING 26.1 1.01E-07 3.8E-09 26.9 1.04E-07 IINH 0.542 2.09E-09 0.552 2.13E-09 IAR 3.83E-02 2.12E-11 5.5E-10 3.43E-02 1.91E-11 ISF 6.68E-04 8.80E-14 1.3E-10 5.60E-04 7.40E-14 IGW 0.196 8.93E-14 4.6E-13 0.769 2.49E-13 IL-CC MI Timber 1.21E-07 Newsprint 1.14E-7 Here 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_CC The 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 value Newsprint requires outside energy which results in a higher IINH . Newsprint process has about 6% lower life cycle composite index. Lower Weighting Factor 135

Interpretation Impact Assessment Inventory Analysis Goal and Scope Definition The LCI data require interpretation Interpretation: “The objectives of life cycle interpretation are to analyze results, reach conclusions, explain limitations and provide recommendations based on the findings of the preceding phases of the LCA or LCI study and to report the results of the life cycle interpretation in a transparent manner.” (ISO 14043) 136

Life Cycle Improvement Analysis
Process improvements to reduce emissions Cellulase seed reactor vent recycle stream Cellulase seed reactor vent stream as combustion air In the interpretation process modifications to the process are analyzed to determine the effects on the 8 environmental indices. 137

Life Cycle Improvement Analysis Seed Reactor Recycle Stream
Recycle 75% of Cellulase seed reactor vent back to the Cellulase seed reactor Recycle stream already at operating pressure Recycle stream contains 90% of required O2 concentration Yellow Poplar 4.8% reduction of compressed air 7.5 % reduction in total utilities 2.2% reduction in IL-CC Newsprint 50% reduction in compressed air 8.6% reduction in utility consumption 6.4% increase in IL-CC In 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.1 138

Life Cycle Improvement Analysis Seed Reactor vent stream recycle
Indices compared to original process Yellow Poplar All indices decreased Less volatile organic compounds released Newsprint Increase in IFT, IING, and ISF Decrease in IGW and IAR This 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

Life Cycle Improvement Analysis Seed Reactor vent stream as combustion air
Volatile Organic Compounds (VOC) from the seed reactor are combusted and used for energy Yellow Poplar 0.4% utilities reduction 20% decrease in ISF, and IING 2.7% reduction in IL-CC News Print 2.1% utilities reduction 18.0% reduction in IL-CC 140

Life Cycle Improvement Analysis Seed Reactor vent stream as combustion air
Indices compared to original process The smog formation indices decrease significantly as a result of utilizing the heating value of ethanol to offset natural gas usage Reduction in the ingestion index also results from less ethanol in the vent stream 141

Life Cycle Assessment Conclusions
Newsprint Pros Less fossil fuel required in pre-manufacturing Lower ecotoxicity Lower overall IL-CC Cons Manufacturing process is not energy self sufficient Higher index for IING, IINH, ICING, ICINH, and IGW Yellow Poplar Timber Manufacturing process is self sufficient and exports electricity to the grid Lower global warming index Lower impacts to human health More fossil fuel required in pre-manufacturing Higher ecotoxicity Higher overall IL-CC 142

Life Cycle Assessment Conclusions
Main chemical contributors to indices acetic acid Carbon monoxide Ethanol Fossil fuel energy required to produce transportation fuel Yellow Poplar (ethanol)- 14% of energy content Newsprint (ethanol)- 27% of energy content Petroleum (gasoline/diesel)- 20% additional energy needed Future Work Impacts of large scale timber harvesting need to be examine Additional studies comparing biomass-to-ethanol facilities to petroleum refineries needed to evaluate local health impacts1 143

LCA Overall Review What you learned how to
Define the goals and scope of a LCA Perform inventory analysis Perform an impact assessment Examples reviewed Copy paper case study Building material case study Bioethanol case study 144

Copy Paper Case Study Review
The Recycling scenario has the smallest carbon footprint Landfill carbon footprint is highly dependent on the methane recovery rate Increased recycling may reduce green house gas emissions Increased recycling may impact the wood market These impacts are outside the scope of the study 145

Housing Case Study Review
Atlanta house Wood- 512 GJ embodied energy Concrete- 573 GJ embodied energy 26% higher emissions 120% higher emissions when including carbon sequestered Minneapolis 727 GJ embodied energy Steel frame- 840 GJ embodied energy 31% higher emissions 156% higher emissions when including carbon sequestered 146

LCA Overall Review LCA has a great potential to help decrease the impacts of industrial processes LCAs can be a powerful marketing tool LCA can be an effective means to quantify and minimize emissions LCA may become increasingly important with the introduction of carbon credits 147

References Energy 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

Environmental Life Cycle Assessment

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