A comparative life cycle assessment: Polyethylene and starch foams.

摘要

Recent federal initiatives to support biomass R & D suggest the importance of having viable alternatives to foreign oil be economically and environmentally attractive. This thesis explores the environmental value of the bio-based starch foam and the petrochemical-based PE foam via a comparative LCA while constructively commenting on the methodological approach. This study follows the methodology outlined in the ISO 14040 standards. Data and models are gathered directly from or from collaborations between Argonne, Cargill Dow, US EPA, NIST, and more. Eight impact categories are covered, each normalized to the associated U.S. normalization value. The total energy required for producing 17,000 ft3 of PE and starch foam are 1.1E6 MJ and 1.02E5 MJ respectively. This makes PE foam production an energy intensive process and, with high energy prices, starch foams may be economically attractive. The impact assessment results reveal PE foam to have the greatest domination with the ozone and global warming potentials by being almost five times greater than the associated starch value and being the only contributor, respectively. Starch foam dominates one of the seven impact categories---the eutrophication potential---and only by 19%. From the results, areas of improvement have been identified. Unfortunately, data is a limiting factor and should be taken into consideration when reviewing the results. This study not only provides a numerical record of a bio-based and petrochemical-based product, but it discloses LCA as a viable benchmarking tool and as a guide for improving processes, while providing constructive recommendations for future life cycle assessments.