Life Cycle Assessment Goals
When we started producing resin at Entropy we thought about the impact we would have on the world. How environmentally friendly were we really? We knew it was important to provide an accurate picture of the true environmental trade-offs in the product selection Entropy offers.
This is what the Life Cycle Assessment (LCA) achieved for us. It provides us the framework that measures the impact our products have. It sets parameters for us and goals to achieve. We are doing good! However, we are aiming for better!
The goal of our LCA was to guide our decision-making process from the data of our operations. The overall goal for us was to make a product that consumers feel good about using. A product that holds a high quality and more importantly is sustainable.
Life Cycle Assessment Objectives
The goal of this study is to understand the cradle-to-gate (Includes raw material extraction and manufacturing of the LER product) environmental impacts of the bio-based liquid epoxy resin (LER) formulation produced by Entropy Resins for America’s market. We also wanted to compare bio-based LER formulation to the same formulation using industry average petrochemical-based components.
The intended applications include informing Entropy Resins’ marketing activities, external communication, and informing product sustainability strategies. Entropy Resins wishes to communicate the results of the LCA publicly to their customer. Therefore, the LCA model and report follow ISO 14040 (ISO, 2006a) and 14044 (ISO, 2006b) requirements for LCA studies intended to be disclosed publicly.
Life Cycle Assessment Function
Liquid epoxy resins represent a very versatile and durable group of thermoset plastic polymers that can be used as a protective coating on various substrates, as a casting polymer to encapsulate or pour into a mold, as a general adhesive to bond materials together, or as a resin medium in a fiber-reinforced composite laminate. For Entropy Resins the main epoxy applications include fiber-reinforced composites, adhesives, coatings, castings, or embedment.
Functional Units
A functional unit identifies the primary function(s) of a system based on which alternative systems are considered functionally equivalent (ISO 14040, 2006). This facilitates the determination of reference flows for each system, which in turn facilitates the comparison of two or more systems. Based on the identified function, the following functional unit was used to determine the reference flows: 1 kilogram of LER packaged for distribution to customers.
System Boundaries
System boundaries are established in LCA in order to include the significant life cycle stages and unit processes, as well as the associated environmental flows in the analysis. This lays the groundwork for a meaningful assessment were all important life cycle stages, and the flows associated with each alternative, are considered. The image below details the system boundaries for both LER Products. The bio-based LER uses bio-based epichlorohydrin (ECH-B), while the petrochemical-based LER uses petrochemical-based epichlorohydrin (ECH-P).
Excluded Processes
Typically in an LCA, some aspects within the set boundaries are excluded due to statistical insignificance or irrelevance to the goal and scope. The following impacts were also excluded from the scope and boundaries of our study:
• Human activities (e.g., employee travel to and from work)
• R&D (i.e., the laboratory and inputs related to the development of the technologies)
• Services (e.g., the use of purchased marketing, consultancy services, and business travel)
Cut-Off Criteria
Cut-off criteria are often used in LCA practice for the selection of processes or flows to be included in the system boundary. The processes or flows below these cut-offs or thresholds are excluded from the study. Several criteria are used in LCA practice to decide which inputs are to be considered, including mass, energy, and environmental relevance. In the current study, every effort was made to include all the flows associated with the processes studied. During the interpretation phase, 1% of the environmental relevance criterion is used to test the sensitivity of the results to assumptions and data substitutions made.
Assumptions
Study assumptions included the following:
• The formulation is the same between the bio-based LER product and the industry average petrochemical-based LER product.
• Ecoinvent’s epoxy resin with a slight modification (fatty alcohol replacing BPA) is used to model C12-C14 Alkyl Glycidyl Ether. This process is the closest representation of this material.
Allocation & Recycling
While conducting an LCA, if the life cycles of more than one product are connected, allocation of the process inputs should be avoided by using the system boundary expansion approach. If allocation cannot be avoided, an allocation method – based on physical causality (mass or energy content, for example) or any other relationship, such as economic value – should be used (ISO 14044 2006).
This study uses the cut-off approach method for recycling. According to this approach, the first life of material bears the environmental burdens of its production (e.g., raw material extraction and processing) and the second life bears the burdens of refurbishment (e.g., collection and refining of scrap). The burdens from waste treatment are taken by life after which they occur (Frischknecht, 2010). This method is applied in the secondary data utilized in the study.
Impact Assessment Method
Impact assessment methods are used to convert LCI data (environmental emissions and raw material extractions) into a set of environmental impacts. ISO 14044 does not dictate which impact assessment method to use for a comparative assertion. However, the chosen method needs to be an internationally-accepted method if the results are intended to be used to support a comparative assertion disclosed to the public.
The primary impact assessment method used for this study is the ReCiPe 2016 Endpoint (H) v1.03 method (Huijbregts MAJ, 2017). The reCiPe is one of the most robust and updated methods available to LCA practitioners. Using the endpoint method, environmental impacts are able to be assessed for Human Health, Ecosystems, and Resources.
In addition to the ReCiPe 2016 Endpoint method, three midpoint impact categories are used: Cumulative Energy Demand (Frischknecht et al. 2007), Climate Change (IPCC 2013), and Water Use (Huijbregts MAJ, 2017). These six categories are found to be of interest and readily understandable to readers of LCA reports. For purposes of simplicity, the combination of the ReCiPe Endpoint method and the selected midpoint categories is called the LTS Method, summarized in the table below.
Each impact category above is characterized by a unit of measure to which the resource and emission flows are normalized. To aggregate the substances into the impact categories, substances are multiplied by their characterization factor to convert into an equivalent substance (e.g., CO2) and then added together to create a total for each impact category (e.g., climate change).
Calculation Tool
Once all the required data was obtained and the associated flows were normalized to the reference flows (based on the chosen functional unit), system modeling was carried out by using the commercial LCA software SimaPro (Version 9.0.0.47), developed by PRé Consultants in the Netherlands. This software allows the calculation of life cycle inventories and impact assessment, contribution analysis, parameterization, and related sensitivity analysis and uncertainty analysis.
Critical Review
A critical review is required by ISO 14044 for comparative assertions intended for public dissemination. The critical review is a process that ensures consistency between a life cycle assessment and ISO requirements for carrying out an LCA. The main purpose of a critical review is to ensure ISO compliance. The critical review is carried out by an LCA expert in order to decrease the likelihood of miscommunication and a negative effect on public knowledge. As outlined by ISO 14044, the role of the critical review is to determine if:
• The methods used to carry out the LCA are consistent with this International Standard
• The methods used to carry out the LCA are scientifically and technically valid
• The data used are appropriate and reasonable in relation to the goal of the study
• The interpretations reflect the limitations identified and the goal of the study
• The study report is transparent and consistent
The critical review was conducted by Cashion East of Pivot Analytics.
The critical review does not imply that the reviewer endorses the results of the LCA study, or that they endorse the assessed products. The critical review statement is provided in Appendix C: Critical Review Statement.
Limitation of the Study
The results of the study are only applicable to the defined scenarios. Any adjustment of the study boundaries or processes may change the results. This study uses a generic formulation of the bio-based LER product, which is also used for the industry average petrochemical LER product.
LCA’s ability to consider the entire life cycle of a product makes it an attractive tool for the assessment of potential environmental impacts. Nevertheless, like other environmental management analysis tools, LCA has several limitations.
With the current availability of data, it is nearly impossible to follow the entire supply chain associated with the product life in a company-specific way. Instead, almost all processes within the supply chains are modeled using average industry data with varying amounts of specificity (e.g., data on a more-or-less specific technology or region). This makes it difficult to accurately determine how well the unit process data actually represents the actual factors in the products’ life cycle. It also makes it difficult to know in which region the processes are found.
Furthermore, LCA is based on a linear extrapolation of emissions with the assumption that all the emissions contribute to an environmental effect. This is contrary to threshold-driven environmental and toxicological mechanisms. Thus, while the linear extrapolation is a reasonable approach for more global and regional impact categories such as climate change and acidification, it may not accurately represent the actual on-the-ground human- and ecotoxicity-related impacts.
Additionally, even if the study was critically reviewed, it should be noted that, as for any LCA, the impact assessment results generated for this study are relative expressions and do not predict impacts on category midpoints, exceeding thresholds, or risks. It should also be noted that, even though LCA covers a wide range of environmental impact categories, some types of environmental impacts (e.g., noise, social, and economic impacts) are typically not included in LCA.
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*Long Tail Sustainability is a third-party product stewardship practitioner used to create LCA models for our products that are based on international standards.