GPEC 2004 Paper Abstract #37: Title: Soy vs. Petro Polyols, A Life Cycle Comparison. Author(s): J. Pollack, Omni Tech International, Ltd.

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1 GPEC 2004 Paper Abstract #37: Title: Soy vs. Petro Polyols, A Life Cycle Comparison Author(s): J. Pollack, Omni Tech International, Ltd. The 2002 Farm Bill contains a section that mandates all federal agencies establish a preferred procurement action program for the purchase and use of biobased products. In support of that mandate, the USDA is charged with issuing criteria that would qualify products for such preference. USDA is also directed to establish a voluntary labeling program known as: USDA Certified Biobased Product. This program will require the use of life cycle modeling. To assess the feasibility of this initiative, a life cycle project was conducted to compare the environmental impacts of two soy polyol materials with a conventional petroleum derived polyol. These polyols are a primary ingredient in manufacturing polyurethane foam products for a variety of applications. This modeling was conducted using the U.S. National Institute of Standards and Technology (NIST) updated BEES software model. Omni Tech Int l. Ltd. of Midland, MI was the consulting firm used to gather mass balance data for the production of the soy polyols. The soy based feedstocks showed only about one quarter the level of total environmental impacts with significant reductions in global warming, smog formation, ecological toxicity and fossil fuel depletion. This life cycle information is now available to any product developer who is considering the use of a soy-based feedstock and wishes to conduct life cycle assessments on their downstream commercial products. The presentation will describe how this information was gathered, used and interpreted.

2 Soy vs. Petro Polyols A Life Cycle Comparison By James W. Pollack Omni Tech International, Ltd. The 2002 Farm Bill contains a provision mandating federal agencies to establish a preferred procurement action program for the purchase and use of biobased products. In support of that mandate, the US Department of Agriculture (USDA) is charged with issuing criteria that would qualify products for such preference. USDA is also directed to establish a voluntary labeling program known as: USDA Certified Biobased Product. This program will require the use of life cycle modeling and USDA has selected the National Institute of Standards and Technology (NIST) BEES (Building for Environmental and Economic Sustainability) software model for that purpose. To assess the feasibility of this initiative, a pilot life cycle project using BEES was conducted to compare the respective life cycles and environmental impacts of two soy polyol materials with a conventional petroleum derived polyol. These polyols are a primary ingredient in manufacturing polyurethane foam products for a variety of applications. Omni Tech Int l. Ltd. of Midland, MI was the consulting firm retained to gather mass balance information for NIST and to interpret the final results. The BEES software model was developed by NIST with support from the U.S. EPA Environmentally Preferable Purchasing Program. This model, which was first introduced in 1994, was originally created to compare the life cycle cost and use of building materials. Over 400 environmental flows from raw material acquisition through product disposal are used to create a detailed mass balance known as a life cycle inventory (LCI) for each material being investigated. The LCI data is then run through the BEES 1

3 model to obtain an economic life cycle cost and 12 environmental impact scores. To better adapt the BEES model for products manufactured from biobased feedstocks, NIST convened a Biobased Advisory Group in late 2002 to update the publicly available LCI datasets for 8 agricultural feedstocks. These feedstocks included: corn, soybeans, wheat, canola, wool, rice straw, cotton and starch from potatoes. Two Omni Tech people served on this Advisory Group and they were responsible for updating the soybean agricultural LCI mass balance database. This work activity was very important as the older datasets contained several inaccuracies such as high use rates for irrigation water, fertilizer, herbicide and pesticide plus high soil erosion and runoff rates. In addition, the crop yield rates were at least 10% too low which adversely influenced the mass balance output when converted to a unit basis (kg) of biobased feedstock. It was also discovered that the model did not recognize the uptake of carbon dioxide during the crop growth phase and that omission affected the BEES impact score for global warming. At the 2003 GPEC meeting, the author presented a case history of how these older datasets affected the BEES modeling of two different foam backed nylon carpet systems. One carpet had a soy polyol foam precoat component while the other carpet had a petroleum based polyol foam component. The results of that modeling (Figure 1) showed that the carpet with soy polyol had a less favorable environmental impact score than the petro polyol carpet. An analysis of the individual impacts identified the global warming, water intake and eutrophication score differentials as contributing to the overall unfavorable environmental impact score. If this data were to be accepted at face value, there would be an environmental disincentive to specify a soy polyol foam material. When the above case history was presented to the Biobased Advisory Group, Omni Tech was asked to gather updated information on the inputs and outputs related to soybean agriculture. This task was accomplished by seeking data from people knowledgeable in the agricultural field. This updated information revealed less pesticide, herbicide and fertilizer use and subsequent runoff loss; much less irrigation usage and increased soybean crop yields. The Advisory Group also recognized the need to account for the carbon dioxide taken up during the growth phase for all biobased feedstocks. Collectively these updated inputs and outputs were incorporated into a new soybean agriculture life cycle inventory database 2

4 which has become the publicly available life cycle database platform for all downstream products made with a soybean derived feedstock. As mentioned earlier in this paper, there was interest in testing the performance of this new LCI database by modeling a downstream soybean based product and soy polyol was selected for this pilot test. Two soy polyol products from Urethane Soy Specialties Corporation (USSC) were offered for this modeling. For comparison purposes, a petroleum based polyol LCI was provided by a NIST subcontractor, PricewaterhouseCoopers (PwC), which has access to a global manufacturing LCI database of over 1,000 industrial products. PwC was also a member of the Biobased Advisory Group as they were responsible for updating the LCIs for the seven other biobased feedstocks. The results of the polyol modeling using the updated soybean agriculture LCI were dramatic. The BEES modeling of the two soy polyols showed favorable environmental impacts for 9 of the 12 defined impacts when compared to the petroleum based polyol. However, the total combined BEES environmental impact score for the two soy polyols was still unfavorable due to one environmental impact defined as Habitat Alteration. The score of this single impact overshadowed all the other positive impacts by a wide margin even when its relative impact weight with respect to the other 11 impacts was reduced to 1% and the others were weighted equally. Typically, all impacts are given equal weighting. An examination of how this impact score was calculated revealed that the use of land for growing a crop was given a high impact rating since it was assumed that virgin land was being converted to cropland and a loss of Threatened and Endangered species would occur. Omni Tech was able to provide evidence to NIST and EPA, who had modified this impact rating system for biobased products, that this criteria did not reflect real life conditions since it would not be necessary to create new cropland due to an excess inventory of available, fallow cropland. It was also argued that if the Habitat Alteration impact scoring criteria were not revised, no biobased feedstock would have a favorable environmental impact score compared to a petroleum-based material. After much discussion, NIST and EPA did agree to limit the Habitat Alteration impact to the land area needed for landfill disposal at the end of the material s useful life. This change in how the Habitat Impact score was calculated would equalize that impact for both the soy and petroleum polyols as their respective end-of-life fates are considered to be comparable. 3

5 NIST then remodeled all three polyols using the amended environmental impact scoring system. The observed environmental impact scores for the soy polyol showed only about one quarter the level of those defined for the petro polyol. This is in contrast to the polyurethane foam backed carpeting modeling project where the environmental score for soy polyol was slightly higher (worse) than the petro polyol. The most significant reductions in impact scoring were noted for: global warming (CO2 sequestration) smog formation (less VOC emitted) ecololgical toxicity (less chemical loss in life cycle) eutrophication (less pollution to surface waters) fossil fuel depletion (less dependence on petroleum) The soy polyols did show a less favorable impact score due to water used in converting soybeans to polyol. These results are shown graphically in Figure 2. What is the significance of this information? These life cycle results confirm the positive environmental aspects and impacts of utilizing a biobased material in place of a petroleum feedstock. In most cases, the product performance and costs are competitive which bode well for the future of biobased products. The availability of a peer reviewed LCI database for soy polyol will aid the product developer who is evaluating a soy derived feedstock and wishes to conduct a life cycle assessment on their downstream commercial products. Utilizing this LCI will reduce the time and cost to conduct such an assessment. 4

6 Fig. 1 Foam backed carpeting comparison Fig. 2 Soy vs. Petrol polyol comparison 5