Primary Energy Demand - PET Bottles

<p>Life Cycle Assessment of beverages in single-use PET bottles using the NREL-maintained US LCI database for the core of the model (polymer production, energy and fuel cycle, combustion). The bar graph indicates the breakdown of energy usage associated with delivering beverages packaged in injection stretch blow molded polyethylene terephthalate (PET) to consumers in California. The functional unit of this analysis is 1 kg of PET resin used in beverage bottles. The model also includes 0.14 kg of polypropylene (PP) resin, required by the product system for caps and labels. The product system delivers 27.9 L of beverage to California consumers, and results in 0.56 kg of secondary (post-recycled) PET resin that can be used to make new bottles or for other purposes. One kg of PET resin is sufficient to contain 27.9 L of beverages, assuming a typical beverage market mix of 60% bottled water, 16% carbonated soft drinks, and 24% juice / sports and other drinks. In California in 2009, 73% of PET bottles in the state's deposit program ("CA CRV") were recycled and 27% were disposed in landfills. The graph depicts this mix (ie. energy requirements reported for materials recovery and reclamation are associated with recovering 0.73 kg of PET bottles). The model excludes production of capital equipment such as factories, vehicles, and machinery; infrastructure such as power plants, fossil fuel extraction equipment, pipelines, roads, and electric grids; land use and water use; and direct human activity. The analysis omits polymer resin additives, inks, dyes, and adhesives; building and administrative overhead; production of the beverage itself; and retail / marketing. The data are from a report to the California Department of Toxic Substances Control, presently under review. Publication in the literature is forthcoming.</p

Antelope – a web service for publishing life cycle models and results

<p>Preparing a life cycle assessment (LCA) requires collecting vast and varied information about industrial processes, known collectively as life cycle inventory (LCI) data. Inventory data for a given study may include a mix of proprietary information, literature results, and data sets drawn from reference databases as well as direct observations, statistical models, and estimates. Exchange and cooperative review of LCI models is challenging, because the use of private data often requires that intermediate results be concealed. Variations in modeling assumptions, scope and system boundary definitions across studies make conclusions difficult to generalize. Moreover, technical differences across software systems and the lack of a data format for publishing finished models also limit the ability of LCA practitioners to disseminate their results to a broad audience. As a consequence, it is often difficult to determine the provenance of LCA results, leading to low confidence in their interpretation.<br>To address the need of study authors to share their results, we have developed a web service that enables the publication of LCI models and impact assessment (LCIA) results while protecting the privacy of source data. Models are constructed out of “fragments,” acyclic directed graphs in which nodes correspond to unit processes and edges correspond to intermediate flows. Nodes are weighted according to their activity levels in a manner consistent with widespread LCA practice. Fragments can be arranged hierarchically by a study author to describe complex models. Using the service, processes and fragments can be inspected, and LCIA results for both processes and fragments can be retrieved for LCIA methods that are implemented by the service. Individual model components (processes, flows, flow properties, and LCIA methods) are referenced to source files formatted according to the ILCD standard. Processes originating from datasets marked as “private” report only aggregate LCIA results, while non-private processes can be inspected at the flow level.<br>The service permits remote users to retrieve modeling information and LCIA results from any web terminal. The work product is designed according to the REST architectural style, meaning that queries to the service are easily intelligible, stateless, and return self-documenting and human-readable results to a user. The results can also be processed by a specialized “front-end” tool and displayed interactively. The API specification and source code are available from the sponsor agency and will be released under an open source license.</p> <p> </p