Browsing by Subject "recycling"
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Item 1988 Minnesota State Survey: Results and Technical Report.(Minnesota Center for Survey Research (MCSR), 1989) Minnesota Center for Survey ResearchItem 1995 Minnesota State Survey: Results and Technical Report.(Minnesota Center for Survey Research (MCSR), 1996) Minnesota Center for Survey ResearchItem 2004 Minnesota State Survey. Results and Technical Report.(Minnesota Center for Survey Research (MCSR), 2004) Minnesota Center for Survey ResearchItem 2005 Minnesota State Survey--Part II: Results and Technical Report.(Minnesota Center for Survey Research (MCSR), 2005) Minnesota Center for Survey ResearchItem Automobile Recycling Alternatives: Why Not? A Look at the Possibilities for Greener car Recycling.(1997) Altschuller, AlisonItem Bringing About Pro-Environment Behavior Through Policies and Social Norms(2019-07) SANKAR, ASHWINIAs human population and consumption have risen, waste generation and air pollution have also increased leading to steady environmental degradation. To stem overflowing landfills and combat air pollution, policies and social norms have often been used as tools to bring about change. My dissertation analyzes the impact of these tools to achieve pro-environment behavior. The first chapter tries to understand two such behaviors, i.e., how to increase recycling and reduce waste. They are key to protecting natural resources, but households probably do not derive any benefit from recycling other than social approval. Based on a theoretical model I built for households, I show that when the social norm of recycling increases, the recycling rate of the household rises and waste per capita falls. My paper is one of the first to test these propositions empirically for Minnesota data using an instrumental variable setup. I show that while waste per capita declines significantly with an increase in social capital, recycling rate does not seem to be influenced by social capital. My second chapter studies the impact of environmental regulations in India on mortality that includes all causes and all ages (or mortality). We know that chronic exposure to air pollution is more harmful to adults than babies and hence focus on mortality as the outcome, for the first time for India. Using a difference-in-differences framework, in the first part of the paper, I show that environmental regulations in India have led to a significant drop in mortality. The second part analyzes the effect of different pollution types on mortality, where I show that PM2:5 exposure is more harmful to mortality (but not infant mortality) than TSP. This further strengthens the claim that policies should focus on adults and shift its focus from TSP to PM2:5 to get greater gains in health. The last chapter studies the functional form of the relationship between PM2:5 concentrations and mortality for the first time for India. The shape of this concentration-response curve will determine if the air in India affects public health at a different or the same rate as the U.S. baseline rate. My paper is one of the first studies to analyze this relationship using panel data for India, without simply extrapolating coefficients from U.S. or European data, following a rigorous identification strategy. I then arrive at the relative risk of mortality estimates at higher pollution concentrations as well as the estimated lives saved due to the reduction in pollution exposure.Item Building a Strategy for Marketing Minnesota's Secondary Materials.(1989) Peek, Thomas R.Item Building a Strategy for Marketing Minnesota's Secondary Materials. Executive Summary: A Blueprint for Action.(Center for Urban and Regional Affairs, University of Minnesota, in cooperation with The Minnesota Project, 1990) Peek, Thomas R.Item Building a Strategy for Marketing Minnesota's Secondary Materials. Volume I: Market Status Report.(Center for Urban and Regional Affairs, University of Minnesota, in cooperation with The Minnesota Project, 1990) Peek, Thomas R.Item Building a Strategy for Marketing Minnesota's Secondary Materials. Volume II: A Blueprint for Action.(Center for Urban and Regional Affairs, University of Minnesota, in cooperation with The Minnesota Project, 1990) Peek, Thomas R.Item Data for Threading-the-Needle: Compatibilization of HDPE/iPP blends with butadiene-derived polyolefin block copolymers(2023-07-31) Shen, Liyang; Diaz Gorbea, Gabriela; Danielson, Evan; Cui, Shuquan; Ellison, Christopher J; Bates, Frank S; bates001@umn.edu; Bates, Frank S; University of Minnesota Department Chemical Engineering and Material ScienceManagement of the plastic industry is a momentous challenge, one that pits enormous societal benefits against an accumulating reservoir of nearly indestructible waste. A promising strategy for recycling polyethylene (PE) and isotactic polypropylene (iPP), constituting roughly half the plastic produced annually worldwide, is melt blending for reformulation into useful products. Unfortunately, such blends are generally brittle and useless due to phase separation and mechanically weak domain interfaces. Recent studies have shown that addition of small amounts of semicrystalline PE-iPP block copolymers (ca. 1 wt%) to mixtures of these polyolefns results in ductility comparable to the pure materials. However, current methods for producing such additives rely on expensive reagents, prohibitively impacting the cost of recycling these inexpensive commodity plastics. Here, we describe an alternative strategy that exploits anionic polymerization of butadiene into block copolymers, with subsequent catalytic hydrogenation, yielding E and X blocks that are individually melt miscible with PE and iPP, where E and X are poly(ethylene-ran-ethylethylene) random copolymers with 6% and 90% ethylethylene repeat units, respectively. Cooling melt blended mixtures of PE and iPP containing 1 wt% of the triblock copolymer EXE of appropriate molecular weight, results in mechanical properties competitive with the component plastics. Blend toughness is obtained through interfacial topological entanglements of the amorphous X polymer and semicrystalline iPP, along with anchoring of the E blocks through cocrystallization with the PE homopolymer. Significantly, EXE can be inexpensively produced using currently practiced industrial scale polymerization methods, offering a practical approach to recycling the world’s top two plastics.Item Green Institute Deconstruction and Used Building Materials Health and Safety Research Project.(1998) Johnson, Anne MarieItem Health and Safety at Deconstruction Services.(1999) Thompson, Faye and Diana WolfItem High-Temperature Chemistry of Polypropylene Pyrolysis: Millisecond Reaction Kinetics and Visualization(2023-06) Sidhu, NathanThe ubiquity of plastics in modern life is evident by the rapid and continual growth of global plastic production. Polypropylene is one of the most widely produced and used plastic materials, accounting for approximately 20% of global polymer production. Billions of tons of plastic waste have been produced as a byproduct of the widespread use of plastics and are insufficiently managed under the current linear plastic economy, with the majority of plastic waste accumulating in landfills or the environment. To allow for the continued use of plastics in a sustainable fashion, a transition must be made towards a circular plastic economy, wherein end-of-life plastics are recycled in a closed loop, fully regenerating the original polymers. To realize a circular plastic economy, new recycling techniques must be developed. Pyrolysis, the thermal conversion of a material in an inert atmosphere, is a high-potential technology to help enable a circular plastic economy. Currently, the fundamental understanding of plastic pyrolysis is limited but will be essential for the development of industrially relevant waste management solutions. The quantification of the intrinsic reaction kinetics of plastic pyrolysis is an ongoing challenge, owing to the complexity of pyrolysis chemistry and the limitations of existing analytical techniques. In this work, a new Pulse-Heated Analysis of Solid Reactions (PHASR) technique was developed that is uniquely capable of operation under reaction-controlled conditions absent transport limitations to measure the millisecond intrinsic kinetics of polyolefin pyrolysis. The capabilities of this reactor to pyrolyze polyolefins under kinetically limited, isothermal conditions with millisecond scale control were extensively validated. A second, Visual PHASR reactor system was developed that enables in situ observation of reaction polyolefins via high-speed photography. Observations of reacting polyolefins revealed the presence of reaction phenomena, including a potential Leidenfrost effect. The intrinsic millisecond reaction kinetics of polypropylene pyrolysis were successfully quantified. The overall reaction kinetics were described by a lumped first-order consumption model with an activation energy of 242.0 ± 2.9 kJ mol-1 and a pre-exponential factor of 35.5 ± 0.6 ln(s-1). Additionally, the production of the solid residues formed during polypropylene pyrolysis was investigated, revealing a secondary kinetic regime.Item Lake of the Woods Sustainability Assessment(The Hubert H. Humphrey School of Public Affairs, 2019-05-19) Dix, Alec; Freesmeier, Claire; Helgeson, Erik; Pattsner, MaxItem On the Intrinsic Kinetics of Polyethylene Pyrolysis(2023-05) Mastalski, IsaacGlobal plastic use has grown exponentially over the past several decades, and this has led to a concomitant increase in plastic waste. Because current plastics, and polyolefins such as polyethylene in particular, have become a necessity for modern life, it is unlikely that more sustainable, alternative plastics can displace them anytime soon, so one of the best ways to mitigate plastic waste is to develop more sustainable, alternative recycling methods. Pyrolysis, or thermal degradation under an inert atmosphere, shows great promise in this regard, since it is capable of chemically recycling plastics back to their constituent monomers or to value-added chemicals. However, knowledge of the mechanisms and reaction kinetics underlying polyethylene pyrolysis remains extremely lacking, hindering development of large-scale plastic recycling capabilities. Therefore, the primary objective of this thesis was to investigate those kinetics and shed new light on the reasons behind the vast discrepancies reported in the literature. Fundamental understanding of polyethylene pyrolysis has previously been limited due to an inability to obtain intrinsic reaction kinetics; instead, the literature presently reports only apparent kinetics, which are a combination of intrinsic kinetics and a variety of other transport and system design limitations. In this thesis, an extensive summary of these limitations in other works is presented, and a new system, known as the Pulse-Heated Analysis of Solid Reactions, or PHASR, system was developed to overcome these limitations. The PHASR system is uniquely capable of operating under “isothermal, reaction-controlled” conditions, at which intrinsic kinetics can reliably be measured. The PHASR system was validated extensively to ensure operation in this desired regime, and detailed descriptions of the reactor setup and experimental methodologies are presented. Alongside this system, a second, Visual PHASR system was developed as well, to enable visualization of polyethylene pyrolysis reaction phenomena for the first time, via integrated high-speed photographic equipment. The method of PHASR was then used to study the intrinsic kinetics of polyethylene pyrolysis. Conversion of low-density polyethylene to pyrolysis products was measured over a range of reaction temperatures (550 to 650 °C) and reaction durations (20 ms to 2.0 s), and three distinct product lumps were characterized via integrated gas chromatography and a microgram-resolution balance. Lumped intrinsic reaction kinetics were calculated using these product fractions. The results were further validated by applying a generalized Rice-Herzfeld radical reaction model to the polyethylene pyrolysis system; good agreement was found between this first principles approach and the PHASR experimental data. Additionally, extensive characterization was performed on the residues left behind in PHASR post-pyrolysis, and this helped elucidate new insights into the different reaction timescale regimes that are present during polyethylene pyrolysis.Item Opportunities Offered by Emerging Hydrometallurgical Technologies(University of Minnesota Duluth, 2022-08) Rao, Shashi; Mlinar, Matthew A; Hudak, George J; Kangas, Kevin W; Peterson, Dean MMinnesota has abundant mineral resources, including deposits of iron, iron manganese, copper-nickel- cobalt-platinum group elements, titanium-vanadium, copper-zinc, gold with and without silver, sand, and aggregate. Commercial and industrial byproducts such as mine tailings, industrial residues, and waste electrical and electronic equipment also contain valuable mineral resources. To address significant environmental impact concerns associated with mining, collection and processing of these materials, new processing technology approaches with reduced water and energy consumption and minimal environmental footprints are needed to support production of value-added products. Emerging hydrometallurgical processing technologies offer promising opportunities. Hydrometallurgy techniques have a range of applications from extraction of high-value products from mineral and recycled materials to water remediation to generating secondary products for carbon sequestration. To evaluate the technical, economic, and environmental resiliency of emerging hydrometallurgical innovations, the Minnesota Legislative-Citizen’s Commission on Minnesota Resources (LCCMR) provided funding to the Natural Resources Research Institute (NRRI) to evaluate how to best support the development of emerging hydrometallurgical technologies in the state. To support this effort, NRRI evaluated: 1) A summary of perceived current and future hydrometallurgical needs of stakeholders based on a “voice of customer” (VOC) survey. 2) A discussion of how to apply hydrometallurgical capabilities to Minnesota-specific mineral and waste resources to maximize long-term economic, environmental, and social benefits and resilience. 3) A vision developed to advance Minnesota’s research capabilities in mineral characterization, mineral processing, extraction, and refining via hydrometallurgy that will lead to more efficient and effective utilization of Minnesota minerals and waste resources in the future. This research digs deeper into emerging applications of hydrometallurgical techniques in the production of value-added materials from a range of primary and secondary resources. The report also explores how application of these techniques to regional resources could potentially foster a more diversified minerals economy in Minnesota, develop treatment technologies to protect water resources, utilize regional resources for carbon mineralization, and supply materials required to build clean energy technologies.Item State of sustainable tourism: Assessing waste minimization practices among tourism businesses across time(University of Minnesota Tourism Center, 2013) Qian, Xinyi; Schneider, Ingrid E.; Schmitt, PeterThis study documented implementation of waste minimization practices through time & across tourism entities in a U.S. state.Item Twin Cities Area Survey and Low Income Survey 1984: Summary of Findings on Energy and Environment.(1985) Minnesota Center for Survey Research