Matching Items (36)
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- All Subjects: Membranes
- All Subjects: Biofuels
- All Subjects: E. coli
- All Subjects: Zeolites
- Creators: Chemical Engineering Program
Description
The increased shift towards environmentalism has brought notable attention to a universal excessive plastic consumption and subsequent plastic overload in landfills. Among these plastics, polyethylene terephthalate, more commonly known as PET, constitutes a large percentage of the waste that ends up in landfills. Material and chemical/thermal methods for recycling are both costly, and inefficient, which necessitates a more sustainable and cheaper alternative. The current study aims at fulfilling that role through genetic engineering of Bacillus subtilis with integration of genes from LCC, Ideonella sakaiensis, and Bacillus subtilis. The plasmid construction was done through restriction cloning. A recombinant plasmid for the expression of LCC was constructed, and transformed into Escherichia coli. Future experiments for this study should include redesigning of primers, with possible combination of signal peptides with genes during construct design, and more advanced assays for effective outcomes.
ContributorsKalscheur, Bethany Ann (Author) / Varman, Arul (Thesis director) / Andino, Jean (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Due to the environmental problems caused by global warming, it has become necessary to reduce greenhouse gas emissions across the planet. Biofuels, such as ethanol, have proven to release cleaner emissions when combusted. However, large scale production of these alcohols is uneconomical and inefficient due to limitations in standard separation processes, the most common being distillation. Pervaporation is a novel separation technique that utilizes a specialized membrane to separate multicomponent solutions. In this research project, pervaporation utilizing ZIF-71/PDMS mixed matrix membranes are investigated to see their ability to recover ethanol from an ethanol/aqueous separation. Membranes with varying nanoparticle concentrations were created and their performances were analyzed. While the final results indicate that no correlation exists between nanoparticle weight percentage and selectivity, this technology is still a promising avenue for biofuel production. Future work will be conducted to improve this existing process and enhance membrane selectivity.
ContributorsHoward, Chelsea Elizabeth (Author) / Lind, Mary Laura (Thesis director) / Nielsen, David (Committee member) / Greenlee, Lauren (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor) / Materials Science and Engineering Program (Contributor)
Created2015-05
Description
Depletion of fossil fuel resources has led to the investigation of alternate feedstocks for and methods of chemical synthesis, in particular the use of E. coli biocatalysts to produce fine commodity chemicals from renewable glucose sources. Production of phenol, 2-phenylethanol, and styrene was investigated, in particular the limitation in yield and accumulation that results from high product toxicity. This paper examines two methods of product toxicity mitigation: the use of efflux pumps and the separation of pathways which produce less toxic intermediates. A library of 43 efflux pumps from various organisms were screened for their potential to confer resistance to phenol, 2-phenylethanol, and styrene on an E. coli host. A pump sourced from P. putida was found to allow for increased host growth in the presence of styrene as compared to a cell with no efflux pump. The separation of styrene producing pathway was also investigated. Cells capable of performing the first and latter halves of the synthesis were allowed to grow separately and later combined in order to capitalize on the relatively lower toxicity of the intermediate, trans-cinnamate. The styrene production and yield from this separated set of cultures was compared to that resulting from the growth of cells containing the full set of styrene synthesis genes. Results from this experiment were inconclusive.
ContributorsLallmamode, Noor Atiya Jabeen (Author) / Nielsen, David (Thesis director) / Cadillo-Quiroz, Hinsby (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
The goal of this research project is to create a mixed matrix membrane that can withstand very acidic environments but still be used to purify water. The ultimate goal of this membrane is to be used to purify urine both here on Earth and in space. The membrane would be able to withstand these harsh conditions due the incorporation of a resilient impermeable polymer layer that will be cast above the lower hydrophilic layer. Nanoparticles called zeolites will act as a water selective pathway through this impermeable layer and allow water to flow through the membrane. This membrane will be made using a variety of methods and polymers to determine both the cheapest and most effective way of creating this chemical resistant membrane. If this research is successful, many more water sources can be tapped since the membranes will be able to withstand hard conditions. This document is primarily focused on our progress on the development of a highly permeable polymer-zeolite film that makes up the bottom layer of the membrane. Multiple types of casting methods were investigated and it was determined that spin coating at 4000 rpm was the most effective. Based on a literature review, we selected silicalite-1 zeolites as the water-selective nanoparticle component dispersed in a casting solution of polyacrylonitrile in N-methylpyrrolidinone to comprise this hydrophilic layer. We varied the casting conditions of several simple solution-casting methods to produce thin films on the porous substrate with optimal film properties for our membrane design. We then cast this solution on other types of support materials that are more flexible and inexpensive to determine which combination resulted in the thinnest and most permeable film.
ContributorsHerrera, Sofia Carolina (Author) / Lind, Mary Laura (Thesis director) / Khosravi, Afsaneh (Committee member) / Hestekin, Jamie (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor)
Created2015-05
Description
Ethanol is a widely used biofuel in the United States that is typically produced through the fermentation of biomass feedstocks. Demand for ethanol has grown significantly from 2000 to 2015 chiefly due to a desire to increase energy independence and reduce the emissions of greenhouse gases associated with transportation. As demand grows, new ethanol plants must be developed in order for supply to meet demand. This report covers some of the major considerations in developing these new plants such as the type of biomass used, feed treatment process, and product separation and investigates their effect on the economic viability and environmental benefits of the ethanol produced. The dry grind process for producing ethanol from corn, the most common method of production, is examined in greater detail. Analysis indicates that this process currently has the highest capacity for production and profitability but limited effect on greenhouse gas emissions compared to less common alternatives.
ContributorsSchrilla, John Paul (Author) / Kashiwagi, Dean (Thesis director) / Kashiwagi, Jacob (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor)
Created2015-05
Description
This document outlines the research work done by Shona Becwar in the process design and refinement for the production of sustainable butanol from Clostridium, along with the required background knowledge on the subject. The process that the microbiological organisms go through to produce butanol must be an oxygen free environment for up to 21 days with multiple perforations made into the environment in this period. There was not previously a cost effective method to do this, even in small scale. It was determined that using a butyl rubber septa would allow for the environment to be sustained during the growth process. The pervaporation process was losing butanol product at a rate of approximately 60%, changing the tubing from silicon to stainless steel allowed for a mere 7% loss during the separation process, greatly increasing the prospective of upscaling this process. These improvements to the sustainable butanol production process will allow for a more efficient, therefore more economically competitive product which can be used as a drop in equivalent to the current butanol market.
ContributorsBecwar, Shona Marie (Author) / Nielsen, David R. (Thesis director) / Staggs, Kyle (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
One of the grand challenges of engineering is to provide access to clean water because it is predicted that by 2025 more than two thirds of the world’s population will face severe water shortages. To combat this global issue, our lab focuses on creating a novel composite membrane to recover potable water from waste. For use as the water-selective component in this membrane design Linde Type A zeolites were synthesized for optimal size without the use of a template. Current template-free synthesis of zeolite LTA produces particles that are too large for our application therefore the particle size was reduced in this study to reduce fouling of the membrane while also investigating the nanoparticle synthesis mechanisms. The time and temperature of the reaction and the aging of the precursor gel were systematically modified and observed to determine the optimal conditions for producing the particles. Scanning electron microscopy, x-ray diffraction, and energy dispersive x-ray analysis were used for characterization. Sub-micron sized particles were synthesized at 2 weeks aging time at -8°C with an average size of 0.6 micrometers, a size suitable for our membrane. There is a limit to the posterity and uniformity of particles produced from modifying the reaction time and temperature. All results follow general crystallization theory. Longer aging produced smaller particles, consistent with nucleation theory. Spinodal decomposition is predicted to affect nucleation clustering during aging due to the temperature scheme. Efforts will be made to shorten the effective aging time and these particles will eventually be incorporated into our mixed matrix osmosis membrane.
ContributorsKing, Julia Ann (Author) / Lind, Mary Laura (Thesis director) / Durgun, Pinar Cay (Committee member) / Chemical Engineering Program (Contributor) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The recovery of biofuels permits renewable alternatives to present day fossil fuels that cause devastating effects on the planet. Pervaporation is a separation process that shows promise for the separation of ethanol from biologically fermentation broths. The performance of thin film composite membranes of polydimethylsiloxane (PDMS) and zeolite imidazolate frameworks (ZIF-71) dip coated onto a porous substrate are analyzed. Pervaporation performance factors of flux, separation factor and selectivity are measured for varying ZIF-71 loadings of pure PDMS, 5 wt%, 12.5 wt% and 25 wt% at 60 oC with a 2 wt% ethanol/water feed. The increase in ZIF-71 loadings increased the performance of PDMS to produce higher flux, higher separation factor and high selectivity than pure polymeric films.
ContributorsLau, Ching Yan (Author) / Lind, Mary Laura (Thesis director) / Durgun, Pinar Cay (Committee member) / Lively, Ryan (Committee member) / Barrett, The Honors College (Contributor) / School of International Letters and Cultures (Contributor) / Chemical Engineering Program (Contributor)
Created2014-05
Description
In this research, construction of a model membrane system using Polyvinylidene Chloride-Co Acrylonitrile and Linde Type A zeolites is described. The systems aims to separate out flow through zeolite pores and flow through interfaces between zeolites and polymers through the use of pore filled and pore open zeolites. Permeation tests and salt rejection tests were performed, and the data analyzed to yield approximation of separated flow through zeolites and interfaces. This work concludes the more work is required to bring the model system into a functioning state. New polymer selections and new techniques to produce the membrane system are described for future work.
ContributorsShabilla, Andrew Daniel (Author) / Lind, Mary Laura (Thesis director) / Lin, Jerry (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor)
Created2014-05
Description
This thesis aims to evaluate how in classroom demonstrations compare to regular education techniques, and how student learning styles affect interest in science and engineering as future fields of study. Science education varies between classrooms, but usually is geared towards lecture and preparation for standardized exams without concern for student interest or enjoyment.5 To discover the effectiveness of demonstrations in these concerns, an in classroom demonstration with a water filtration experiment was accompanied by several modules and followed by a short survey. Hypotheses tested included that students would enjoy the demonstration more than a typical class session, and that of these students, those with more visual or tactile learning styles would identify with science or engineering as a possible major in college. The survey results affirmed the first hypothesis, but disproved the second hypothesis; thus illustrating that demonstrations are enjoyable, and beneficial for sparking or maintaining student interest in science across all types of students.
ContributorsPiper, Jessica Marie (Author) / Lind, Mary Laura (Thesis director) / Montoya-Gonzales, Roxanna (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / Chemical Engineering Program (Contributor)
Created2014-05