Matching Items (13)
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- All Subjects: Polymers
- All Subjects: Renewable Energy
- Creators: Chemical Engineering Program
- Member of: Barrett, The Honors College Thesis/Creative Project Collection
Description
This study was conducted to better understand the making and measuring of renewable energy goals by the federal government. Three different energy types are studied: wind, solar, and biofuel, for two different federal departments: the Department of Defense and the Department of Energy. A statistical analysis and a meta-analysis of current literature will be the main pieces of information. These departments and energy types were chosen as they represent the highest potential for renewable energy production. It is important to understand any trends in goal setting by the federal government, as well as to understand what these trends represent in terms of predicting renewable energy production. The conclusion for this paper is that the federal government appears to set high goals for renewable energy initiatives. While the goals appear to be high, they are designed based on required characteristics described by the federal government. These characteristics are most often technological advancements, tax incentives, or increased production, with tax incentives having the highest priority. However, more often than not these characteristics are optimistic or simply not met. This leads to the resetting of goals before any goal can be evaluated, making it difficult to determine the goal-setting ability of the federal government.
ContributorsStapleton, Andrew (Co-author) / Charnell, Matthew (Co-author) / Printezis, Antonios (Thesis director) / Kull, Thomas (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor) / Department of Supply Chain Management (Contributor)
Created2015-05
Description
Increased investigation into the development of macromolecular fluorophores has resulted in the synthesis and discovery of several potential candidates. These include modified and polymeric based dendritic structures, hyperbranched polymers and linear polymers. Strong inherent blue photoluminescence has been recently described in linear polyamine polymers in the absence of any chemical modifications. Here we describe the screening of amine/polyamine compounds for inherent photoluminescence. Several compounds that exhibited strong inherent blue photoluminescence following excitation with UV light were identified. Furthermore we demonstrated successful synthesis of poly(amino ether) polymers as well as chemically cross-linked poly(amino ether) thermosets with the lead Pentaethylenehexamine which was found to have strong inherent blue photoluminescence. The polymers and thermosets were found to retain the photoluminescent properties of the original lead compound. The polymers and thermosets were investigated for their ability to sequester heavy metals from aqueous solutions. An increased decrease in initial photoluminescence was observed as the materials were incubated with increasing metal salt concentration as a result of metal binding sequestration. The poly(amino ether) polymers were found to have higher sensitivity for metal sequestration when compared to equivalent amount of linear 25 kDa polyethylenimine. The strong inherent blue photoluminescence and the ease of synthesis of the poly(amino ether) polymers and thermosets give these materials strong potential for future applications as sensors.
ContributorsVu, Jeffrey (Co-author) / Ramos, James (Co-author) / Rege, Kaushal (Thesis director) / Godeshala, Sudakhar (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor)
Created2015-05
Description
This study aims to provide a foundation for future work on photo-responsive polymer composite materials to be utilized in additive manufacturing processes. The curing rate of 2,2-dimethoxy-2-phenyl-acetophenone (DMPA) in thin (<20 µm) and thick (>2 mm) layers of DMPA and poly(ethylene glycol) diacrylate (PEG-DA) mixtures was assessed for 5.0 w/v% (grams per 100 mL) concentrations of DMPA dissolved in PEG-DA. The polymerization rate and quality of curing was found to decrease as the concentration of DMPA increased beyond 1.0 w/v%; thus, confirming the existence of an optimum photo-initiator concentration for a specific sheet thickness. The optimum photo-initiator concentration for a 3-3.1 mm thick sheet of PEG-DA microstructure was determined to be between 0.3 and 0.38 w/v% DMPA. The addition of 1,6-hexanediol or 1,3-butanediol to the optimum photo-initiator concentrated solution of DMPA and PEG-DA was found to increase the Tg of the samples; however, the samples could not fully cure within 40-50 s, which suggested a decrease in polymerization rate. Lastly, the DMPA photo-initiator does not produce gaseous byproducts and is translucent when fully cured, which makes it attractive for infusion with strengthening materials because quality light penetration is paramount to quick polymerization rates. It is recommended that more trials be conducted to evaluate the mechanical properties of the optimum curing rate for DMPA and PEG-DA microstructures as well as a mechanical property comparison following the addition of either of the two alcohols.
ContributorsPiper, Tyler Irvin (Author) / Green, Green (Thesis director) / Lind, Mary Laura (Committee member) / School of Sustainability (Contributor) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
This study details the construction and operation of a dry-jet wet spinning apparatus for extruding hollow fiber membranes (HFMs). The main components of the apparatus are a spinneret, a coagulation bath, and an automatic collection reel. Continuous fiber formation was achieved using two syringe pumps simultaneously delivering polymer dope and bore fluid to the spinneret. Based on apparatus runs performed with Polysulfone (PSF) dopes dissolved in N,N-Dimethylacetamide and supporting rheological analysis, the entanglement concentration, ce, was identified as a minimum processing threshold for creating HFMs. Similarly, significant increases in the ultimate tensile strength, fracture strain, and Young's modulus for extruded HFMs were observed as polymer dope concentration was increased at levels near ce. Beyond this initial increase, subsequent tests at higher PSF concentrations yielded diminishing changes in mechanical properties, suggesting an asymptotic approach to a point where the trend would cease. Without further research, it is theorized that this point falls on a transition from the semidiute entangled to concentrated concentration regimes. SEM imaging of samples revealed the formation of grooved structures on the inner surface of samples, which was determined to be a result of the low flowrate and polymer dope concentrations used in processing the HFMs during apparatus runs. Based on continued operation of the preliminary apparatus design, many areas of improvement were noted. Namely, these consisted of controlling the collector speed, eliminating rubbing of nascent fibers against the edge of the coagulation bath by installing an elevated roller, and replacing tygon tubing for the polymer line with a luer lock adapter for direct syringe attachment to the spinneret.
ContributorsBridge, Alexander Thomas (Author) / Green, Matthew D. (Thesis director) / Lin, Jerry Y. S. (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
There is an increasing need to understand and develop clean cooking technologies in low- and middle-income countries (LMICs). The provision of clean energy where modern energy is not available is important in advancing the 17 sustainable development goals as set by the United Nations. Green charcoal is a cooking fuel technology made from ground and compressed biochar, an organic material made from heating a feedstock (biomass, forest residues, agriculture waste, invasive species, etc.) in an oxygen deprived environment to high temperatures. Green charcoal behaves similarly to wood charcoal or coal but is different from these energy products in that it is produced from biomass, not from wood or fossil fuels. Green charcoal has gained prominence as a cooking fuel technology in South-East Asia recently. Within the context of Nepal, green charcoal is currently being produced using lantana camara, an invasive species in Nepal, as a feedstock in order to commoditize the otherwise destructive plant. The purpose of this study was to understand the innovation ecosystem of green charcoal within the context of Nepal’s renewable energy sector. An innovation ecosystem is all of the actors, users and conditions that contribute to the success of a particular method of value creation. Through a series of field interviews, it was determined that the main actors of the green charcoal innovation ecosystem are forest resources governance agencies, biochar producers, boundary organizations, briquette producers, distributors/vendors, the political economy of energy, and the food culture of individuals. The end user (user segment) of this innovation ecosystem is restaurants. Each actor was further analyzed based on the Ecosystem Pie Model methodology as created by Talmar, et al. using the actor’s individual resources, activities, value addition, value capture, dependence on green charcoal and the associated risk as the building blocks for analysis. Based on ecosystem analysis, suggestions were made on how to strengthen the green charcoal innovation ecosystem in Nepal’s renewable energy sector based on actor-actor and actor-green charcoal interactions, associated risks and dependence, and existing knowledge and technology gaps. It was determined that simply deploying a clean cooking technology does not guarantee success of the technology. Rather, there are a multitude of factors that contribute to the success of the clean cooking technology that deserve equal amounts of attention in order to successfully implement the technology.
ContributorsDieu, Megan (Author) / Chhetri, Netra (Thesis director) / Henderson, Mark (Committee member) / Chemical Engineering Program (Contributor, Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Polymer-nanoparticle composites (PNCs) show improved chemical and physical properties compared to pure polymers. However, nanoparticles dispersed in a polymer matrix tend to aggregate due to strong interparticle interactions. Electrospun nanofibers impregnated with nanoparticles have shown improved dispersion of nanoparticles. Currently, there are few models for quantifying dispersion in a PNC, and none for electrospun PNC fibers. A simulation model was developed to quantify the effects of nanoparticle volume loading and fiber to particle diameter ratios on the dispersion in a nanofiber. The dispersion was characterized using the interparticle distance along the fiber. Distributions of the interparticle distance were fit to Weibull distributions and a two-parameter empirical equation for the mean and standard deviation was found. A dispersion factor was defined to quantify the dispersion along the polymer fiber. This model serves as a standard for comparison for future experimental studies through its comparability with microscopy techniques, and as way to quantify and predict dispersion in polymer-nanoparticle electrospinning systems with a single performance metric.
ContributorsBalzer, Christopher James (Author) / Mu, Bin (Thesis director) / Armstrong, Mitchell (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
The effect of ammonium on microbial fermentation was investigated to improve the efficiency of microbial electrochemical cells (MXC). Electron balances of anaerobic microbial cultures with varying ammonium concentrations (reported as g N-NH4+/L) were used to study the distribution of electrons from different fermentable substrates to acetate, propionate, and methane. Results showed that with a high ammonium concentration (between 2.25 to 3g N-NH4+/L) fewer electrons routed to methane during the fermentation of 300 me-eq./L of electron donors .The majority of electrons (~ 60-80%) in the serum bottles experiments were routed to acetate and propionate for all fermentable substrates with high ammonium concentration. While methane cannot be utilized by anode respiring bacteria (ARBs) to produce current, both acetate and propionate can, which could lead to higher Coulombic efficiencies in MXCs. Experiments in microbial electrolysis cells (MECs) with glucose, lactate, and ethanol were performed. MEC experiments showed low percentage of electrons to current (between 10-30 %), potentially due to low anode surface area (~ 3cm2) used during these experiments. Nevertheless, the fermentation process observed in the MECs was similar to serum bottles results which showed significant diversion of electrons to acetate and propionate (~ 80%) for a control concentration of 0.5 g N-NH4+/L .
ContributorsLozada Guerra, Suyana Patricia (Co-author) / Joseph, Miceli (Co-author) / Krajmalnik-Brown, Rosa (Thesis director) / Torres, Cesar (Committee member) / Young, Michelle (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor)
Created2013-05
Description
Lithium ion batteries are quintessential components of modern life. They are used to power smart devices — phones, tablets, laptops, and are rapidly becoming major elements in the automotive industry. Demand projections for lithium are skyrocketing with production struggling to keep up pace. This drive is due mostly to the rapid adoption of electric vehicles; sales of electric vehicles in 2020 are more than double what they were only a year prior. With such staggering growth it is important to understand how lithium is sourced and what that means for the environment. Will production even be capable of meeting the demand as more industries make use of this valuable element? How will the environmental impact of lithium affect growth? This thesis attempts to answer these questions as the world looks to a decade of rapid growth for lithium ion batteries.
ContributorsMelton, John (Author) / Brian, Jennifer (Thesis director) / Karwat, Darshawn (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
This thesis explores the investigation of the project “Designing for a Post-Diesel Engine World”, a collaborative experiment between organizations within Arizona State University and an undisclosed company. This investigation includes the analysis of various renewable energy technologies and their potential to replace industrial diesel engines as used in the company’s business. In order to be competitive with diesel engines, the technology should match or exceed diesel in power output, have reduced environmental impact, and meet other criteria standards as determined by the company. The team defined the final selection criteria as: low environmental impact, high efficiency, high power, and high technology readiness level. I served as the lead Hydrogen Fuel Cell Researcher and originally hypothesized that PEM fuel cells would be the most viable solution. Results of the analysis led to PEM fuel cells and Li-ion batteries being top contenders, and the team developed a hybrid solution incorporating both of these technologies in a technical and strategic solution. The resulting solution design from this project has the potential to be modified and implemented in various industries and reduce overall anthropogenic emissions from industrial processes.
ContributorsFernandez, Alexandra Marie (Author) / Heller, Cheryl (Thesis director) / Smith, Tyler (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Fossil fuels have been the primary source of energy in the world for many decades. However, they are among the top contributors of the greenhouse gas emissions in the atmosphere. The objective of this research was to produce a more environmentally friendly biofuel from Algae-Helix and Salicornia biomasses. Experiments were conducted using a hydrothermal liquefaction (HTL) technique in the HTL reactor to produce biofuel that can potentially replace fossil fuel usage. Hydrothermal Liquefaction is a method used to convert the biomass into the biofuels. HTL experiments on Algae-Helix and Salicornia at 200°C-350°C and 430psi were performed to investigate the effect of temperature on the biocrude yield of the respective biomass used. The effect of the biomass mixture (co-liquefaction) of Salicornia and algae on the amount of biocrude produced was also explored. The biocrude and biochar (by-product) obtained from the hydrothermal liquefaction process were also analyzed using thermogravimetric analyzer (TGA). The maximum biocrude yield for the algae-helix biomass and for the Salicornia biomass were both obtained at 300°C which were 34.63% and 7.65% respectively. The co-liquefaction of the two biomasses by 50:50 provided a maximum yield of 17.26% at 250°C. The co-liquefaction of different ratios explored at 250°C and 300°C concluded that Salicornia to algae-helix ratio of 20:80 produced the highest yields of 22.70% and 31.97%. These results showed that co-liquefaction of biomass if paired well with the optimizing temperature can produce a high biocrude yield. The TGA profiles investigated have shown that salicornia has higher levels of ash content in comparison with the algae-helix. It was then recommended that for a mixture of algae and Salicornia, large-scale biofuel production should be conducted at 250℃ in a 20:80 salicornia to algae biocrude ratio, since it lowers energy needs. The high biochar content left can be recycled to optimize biomass, and prevent wastage.
ContributorsLuboowa, Kato Muhammed (Co-author) / Laideson, Maymary (Co-author) / Deng, Shuguang (Thesis director) / Nielsen, David (Committee member) / Chemical Engineering Program (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05