Matching Items (4)
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- All Subjects: Carbon Dioxide
- All Subjects: Plastics
- All Subjects: Thermoplastic composites
- Genre: Academic theses
- Genre: Masters Thesis
- Creators: Allenby, Braden R.
- 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
Research confirms that climate change is primarily due to the influx of greenhouse gases from the anthropogenic burning of fossil fuels for energy. Carbon dioxide (CO2) is the dominant greenhouse gas contributing to climate change. Although research also confirms that negative emission technologies (NETs) are necessary to stay within 1.5-2°C of global warming, this dissertation proposes that the climate change problem has been ineffectively communicated to suggest that CO2 emissions reduction is the only solution to climate change. Chapter 1 explains that current United States (US) policies focus heavily on reducing CO2 emissions, but ignore the concentrations of previous CO2 emissions accumulating in the atmosphere. Through political, technological, and ethical lenses, this dissertation evaluates whether the management process of CO2 emissions and concentrations in the US today can effectively combat climate change.
Chapter 2 discusses the historical management of US air pollution, why CO2 is regulated as an air pollutant, and how the current political framing of climate change as an air pollution problem promotes the use of market-based solutions to reduce emissions but ignores CO2 concentrations. Chapter 3 argues for the need to reframe climate change solutions to include reducing CO2 concentrations along with emissions. It presents the scientific reasoning and technological needs for reducing CO2 concentrations, why direct air capture (DAC) is the most effective NET to do so, and existing regulatory systems that can inform future CO2 removal policy. Chapter 4 explores whether Responsible Innovation (RI), a framework that includes society in the innovation process of emerging technologies, is effective for the ethical research and deployment of DAC; reveals the need for increased DAC governance strategies, and suggests how RI can be expanded to allow continued research of controversial emerging technologies in case of a climate change emergency. Overall, this dissertation argues that climate change must be reframed as a two-part problem: preventing new CO2 emissions and reducing concentrations, which demands increased investment in DAC research, development, and deployment. However, without a national or global governance strategy for DAC, it will remain difficult to include CO2 concentration reduction as an essential piece to the climate change solution.
Chapter 2 discusses the historical management of US air pollution, why CO2 is regulated as an air pollutant, and how the current political framing of climate change as an air pollution problem promotes the use of market-based solutions to reduce emissions but ignores CO2 concentrations. Chapter 3 argues for the need to reframe climate change solutions to include reducing CO2 concentrations along with emissions. It presents the scientific reasoning and technological needs for reducing CO2 concentrations, why direct air capture (DAC) is the most effective NET to do so, and existing regulatory systems that can inform future CO2 removal policy. Chapter 4 explores whether Responsible Innovation (RI), a framework that includes society in the innovation process of emerging technologies, is effective for the ethical research and deployment of DAC; reveals the need for increased DAC governance strategies, and suggests how RI can be expanded to allow continued research of controversial emerging technologies in case of a climate change emergency. Overall, this dissertation argues that climate change must be reframed as a two-part problem: preventing new CO2 emissions and reducing concentrations, which demands increased investment in DAC research, development, and deployment. However, without a national or global governance strategy for DAC, it will remain difficult to include CO2 concentration reduction as an essential piece to the climate change solution.
ContributorsMorton, Evvan (Author) / Lackner, Klaus S (Thesis advisor) / Allenby, Braden R. (Committee member) / Graffy, Elisabeth A. (Committee member) / Arizona State University (Publisher)
Created2020
Description
As the global community raises concerns regarding the ever-increasing urgency of climate change, efforts to explore innovative strategies in the fight against this anthropogenic threat is growing. Along with other greenhouse gas mitigation technologies, Direct Air Capture (DAC) or the technology of removing carbon dioxide directly from the air has received considerable attention. As an emerging technology, the cost of DAC has been the prime focus not only in scientific society but also between entrepreneurs and policymakers. While skeptics are concerned about the high cost and impact of DAC implementation at scales comparable to the magnitude of climate change, industrial practitioners have demonstrated a pragmatic path to cost reduction. Based on the latest advancements in the field, this dissertation investigates the economic feasibility of DAC and its role in future energy systems. With a focus on the economics of carbon capture, this work compares DAC with other carbon capture technologies from a systemic perspective. Moreover, DAC’s major expenses are investigated to highlight critical improvements necessary for commercialization. In this dissertation, DAC is treated as a backstop mitigation technology that can address carbon dioxide emissions regardless of the source of emission. DAC determines the price of carbon dioxide removal when other mitigation technologies fall short in meeting their goals. The results indicate that DAC, even at its current price, is a reliable backup and is competitive with more mature technologies such as post-combustion capture. To reduce the cost, the most crucial component of a DAC design, i.e., the sorbent material, must be the centerpiece of innovation. In conclusion, DAC demonstrates the potential for not only negative emissions (carbon dioxide removal with the purpose of addressing past emissions), but also for addressing today’s emissions. The results emphasize that by choosing an effective scale-up strategy, DAC can become sufficiently cheap to play a crucial role in decarbonizing the energy system in the near future. Compared to other large-scale decarbonization strategies, DAC can achieve this goal with the least impact on our existing energy infrastructure.
ContributorsAzarabadi, Habib (Author) / Lackner, Klaus S (Thesis advisor) / Allenby, Braden R. (Committee member) / Dirks, Gary W (Committee member) / Reddy, Agami (Committee member) / Arizona State University (Publisher)
Created2020