Matching Items (3)
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- All Subjects: Plastics
- Genre: Academic theses
- Genre: Masters Thesis
- Creators: Allenby, Braden R.
- Creators: Biyani, Nivedita
- Member of: Theses and Dissertations
Description
Fossil resources have enabled the development of the plastic industry in the last century. More recently biopolymers have been making gains in the global plastics market. Biopolymers are plastics derived from plants, primarily corn, which can function very similarly to fossil based plastics. One difference between some of the dominant biopolymers, namely polylactic acid and thermoplastic starch, and the most common fossil-based plastics is the feature of compostability. This means that biopolymers represent not only a shift from petroleum and natural gas to agricultural resources but also that these plastics have potentially different impacts resulting from alternative disposal routes. The current end of life material flows are not well understood since waste streams vary widely based on regional availability of end of life treatments and the role that decision making has on waste identification and disposal.
This dissertation is focused on highlighting the importance of end of life on the life-cycle of biopolymers, identifying how compostable biopolymer products are entering waste streams, improving collection and waste processing, and quantifying the impacts that result from the disposal of biopolymers. Biopolymers, while somewhat available to residential consumers, are primarily being used by various food service organizations trying to achieve a variety of goals such as zero waste, green advertising, and providing more consumer options. While compostable biopolymers may be able to help reduce wastes to landfill they do result in environmental tradeoffs associated with agriculture during the production phase. Biopolymers may improve the management for compostable waste streams by enabling streamlined services and reducing non-compostable fossil-based plastic contamination. The concerns about incomplete degradation of biopolymers in composting facilities may be ameliorated using alkaline amendments sourced from waste streams of other industries. While recycling still yields major benefits for traditional resins, bio-based equivalents may provide addition benefits and compostable biopolymers offer benefits with regards to global warming and fossil fuel depletion. The research presented here represents two published studies, two studies which have been accepted for publication, and a life-cycle assessment that will be submitted for publication.
This dissertation is focused on highlighting the importance of end of life on the life-cycle of biopolymers, identifying how compostable biopolymer products are entering waste streams, improving collection and waste processing, and quantifying the impacts that result from the disposal of biopolymers. Biopolymers, while somewhat available to residential consumers, are primarily being used by various food service organizations trying to achieve a variety of goals such as zero waste, green advertising, and providing more consumer options. While compostable biopolymers may be able to help reduce wastes to landfill they do result in environmental tradeoffs associated with agriculture during the production phase. Biopolymers may improve the management for compostable waste streams by enabling streamlined services and reducing non-compostable fossil-based plastic contamination. The concerns about incomplete degradation of biopolymers in composting facilities may be ameliorated using alkaline amendments sourced from waste streams of other industries. While recycling still yields major benefits for traditional resins, bio-based equivalents may provide addition benefits and compostable biopolymers offer benefits with regards to global warming and fossil fuel depletion. The research presented here represents two published studies, two studies which have been accepted for publication, and a life-cycle assessment that will be submitted for publication.
ContributorsHottle, Troy A (Author) / Landis, Amy E. (Thesis advisor) / Allenby, Braden R. (Thesis advisor) / Bilec, Melissa M (Committee member) / Arizona State University (Publisher)
Created2015
Description
With the growing popularity of 3d printing in recreational, research, and commercial enterprises new techniques and processes are being developed to improve the quality of parts created. Even so, the anisotropic properties is still a major hindrance of parts manufactured in this method. The goal is to produce parts that mimic the strength characteristics of a comparable part of the same design and materials created using injection molding. In achieving this goal the production cost can be reduced by eliminating the initial investment needed for the creation of expensive tooling. This initial investment reduction will allow for a wider variant of products in smaller batch runs to be made available. This thesis implements the use of ultraviolet (UV) illumination for an in-process laser local pre-deposition heating (LLPH). By comparing samples with and without the LLPH process it is determined that applied energy that is absorbed by the polymer is converted to an increase in the interlayer temperature, and resulting in an observed increase in tensile strength over the baseline test samples. The increase in interlayer bonding thus can be considered the dominating factor over polymer degradation.
ContributorsKusel, Scott Daniel (Author) / Hsu, Keng (Thesis advisor) / Sodemann, Angela (Committee member) / Kannan, Arunachala M (Committee member) / Arizona State University (Publisher)
Created2017
Description
This thesis examines the composition, flow rate, and recyclability of two abundant materials generated in modern society: municipal sewage sludge (SS) generated during conventional wastewater treatment, and single-use plastic packaging (specifically, plastic bottles) manufactured and dispersed by fast-moving consumer goods companies (FMCG). The study found the presence of 5 precious metals in both American and Chinese sewage sludges. 13 rare elements were found in American sewage sludge while 14 were found in Chinese sewage sludge. Modeling results indicated 251 to 282 million metric tons (MMT) of SS from 2022 to 2050, estimated to contain some 6.8 ± 0.5 MMT of valuable elements in the USA, the reclamation of which is valued at $24B ± $1.6B USD. China is predicted to produce between 819 - 910 MMT of SS between 2022 and 2050 containing an estimated 14.9 ± 1.7 MMT of valuable elements worth a cumulative amount of $94B ± 20B (Chapter 2 and 3). The 4th chapter modeled how much plastic waste Coca-Cola, PespiCo and Nestlé produced and globally dispersed in 21 years: namely an estimated 126 MMT ± 8.7 MMT of plastic. Some 15.6 MMT ± 1.3 MMT (12%) is projected to have become aquatic pollution costing estimated at $286B USD. Some 58 ± 5 MMT or 46% of the total mass were estimated to result in terrestrial plastic pollution, with only minor amounts of 9.9 ± 0.7 MMT, deemed actually recycled. Absent of change, the three companies are predicted to generate an additional 330 ± 15 MMT of plastic by 2050, thereby creating estimated externalities of $8 ± 0.4 trillion USD. The analysis suggests that a small subset of FMCG companies are well positioned to change the current trajectory of global plastic pollution and ocean plastic littering. Chapter 5 examined the barriers to Circular Economy. In an increasingly uncertain post pandemic world, it is becoming progressively important to conserve local resources and extract value from materials that are currently interpreted a “waste” rather than a current or potential future resource.
ContributorsBiyani, Nivedita (Author) / Halden, Rolf U. (Thesis advisor) / Allenby, Braden (Committee member) / Jalbert, Kirk (Committee member) / Arizona State University (Publisher)
Created2022