SALT: Solar and Alternative Technologies Research Experience

What is SALT?

The Solar and Alternative Technologies (SALT) research experience is a 10-week summer research program providing undergraduate students with the opportunity to research and develop exciting alternative energy technologies such as fuel, catalysts, power, energy reservoirs, clean water and plastics from renewable sources or using renewable energy, thereby reducing the world’s dependence on fossil fuels. Students working on SALT projects will learn analytical techniques, responsible conduct and environmental ethics, as well as communication and social media skills through oral and written reports. SALT research will include fascinating technologies such as microalgal biofuel, biocatalysts and nanoellipsoids.

As SALT researchers, students will get a taste of graduate level research, acquire important skills under the mentorship of experienced TU Faculty, see alternative energies in action during field trips and contribute to building a better world through renewable energy.  Please look at the bottom of the page for a description of each research project.  Room, a subsistence stipend for food, and a $500/week traineeship are included.

Field Trips

SALT students will experience alternative energy in action on six local and two one-day field trips to fascinating locations like the Pensacola Dam, Covanta Energy-from-Waste, FRE Renewable Solutions, the Gathering Place, Gilcrease Museum and Redbud Valley Nature Preserve. These trips will include discussion of the challenges those industries face in achieving more widespread use of their technologies.

Faculty Research Mentors

SALT participants will collaborate with experienced faculty research mentors to guide them through the research project. Descriptions of the projects are given after then contact form below.  The mentors include:

Timeline

Application deadline: Sunday, March 8, 2020
Notification of acceptance into the program:  Monday, March 23, 2020
Dates to be on site at the University of Tulsa:  May 26 – Aug. 1, 2020

Have Questions? Check out our Frequently Asked Questions.

Apply using the following link:  SALT Application Form

Contact Information

For more information on the SALT research experience, contact Dr. Laura Ford at laura-ford@utulsa.edu, or by using the contact form below.

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Funded through the National Science Foundation Grant No. 1852477 and 1852351

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Numerical Transport Phenomena in Energy Production (Mentor Dr. Crunkleton)

The University of Tulsa has a long history in energy-related research, including both traditional and alternative energy.  In this REU research area, undergraduate students will have the opportunity to conduct research in model-assisted energy decision making, especially as they pertain to solar energy and biofuel production.  Specifically, we hypothesize that computational fluid dynamics (CFD) simulations will capture fluid and nutrient flows in various solar and biofuel production techniques in a way that will guide future experimental studies.  For solar energy, an insolation model of energy availability will be coupled with a fluid flow and heat transfer algorithm for predicting energy production in various solar configurations.  For biofuels research, CFD techniques are coupled with optimization routines to find the best combination of design and operating conditions that will yield the most economical production of biofuels, especially those that are algae-derived.

 

Hydrate Technology for Desalination Process (Mentor Dr. Daraboina)

Several million gallons of water are treated daily for fracturing, injection, disposal and reuse operations during oil and gas production.  The use of fresh water sources for fracturing operations is discouraged.  Fortunately, over the past decade, the oil and gas industry is making an enormous effort to recycle and re-use produced water from onshore and offshore operations and to use alternate water sources for well operations.  Produced water can contain 500-180,000 mg/L of dissolved solids concentration compared to fresh water (<500 mg/L).  Therefore, it is often times necessary to reduce salinity of these waters prior to reuse or recycle.

 

Current desalination technologies are divided mainly into two categories: thermal and membrane techniques.  The traditional desalination plants based on the multi-stage flash (MSF) distillation and reverse osmosis (RO) processes are reliable and established processes [10] – [11], but they are energy intensive. The energy cost of supplying the projected global water need with present technologies is high – especially in a carbon-constrained world. Overall, there are still opportunities to develop water treatment technologies to process produced water at a large scale with a focus on minimizing energy costs and maximizing water recovery. Recently, hydrate-based desalination (HBD) has been proposed for seawater desalination. The advantage of HBD process is that it is less energy intensive as it operates at temperatures well above the normal freezing point of water [12]. The limitation of slow kinetics can be overcome through the prudent choice of favorable guest gas/liquid, promotor addition, and improved reactor designs. The hypothesis is that the chemistry of promotors is the important factor in increasing the kinetic rate of hydrate formation and decomposition.

 

Objectives:

  • to operate hydrate reactor, differential scanning calorimeter and high temperature gas chromatography
  • to analyze thermodynamic and kinetic data for hydrate process
    S. A. Kalogirou, “Seawater desalination using renewable-energy-sources,” Progress in Energy and Combustion Science, vol. 31, pp. 242 – 281, 2005.
    A. D. Khawaji, I. K. Kutubkhanah and J.-M. Wie, “Advances in seawater desalination technologies,” Desalination, vol. 221, pp. 47 – 69, 2008.
    A. J. Barduhn, H. E. Towlson and Y. C. Hu, “The properties of some new gas hydrates and their use in demineralizing sea water,” AIChE Journal, vol. 8, no. 2, pp. 176 – 183, 1962.

Selenium-based Thin Film Solar Cell Fabrication (Dr. Hari)

Traditionally, photovoltaic (PV) cells are tuned to air mass 1.5 spectrum from the sun. Indoor light can also be used for power in wireless and sensing applications, as well as facilitating algae growth using light emitting diodes, to name a few. The wavelength of the indoor light spectrum maximizes at 1.9 eV, which coincides perfectly with the band gap of selenium. Selenium-based solar cells have been stuck on 5% conversion efficiency for the past four decades [13].

There are two fundamental issues for improving the conversion efficiency of selenium-based PV cells beyond 5%. The first issue is to determine the optimum thickness of the absorption p-layer made of selenium for maximum efficiency. If the thickness is large, it will enable higher absorption [14]. However, the drift-based carriers collected at the back side will be reduced for a thick layer. The diffusion length must be optimized to improve the collection of drift current and efficiency of the PV cell. Secondly, selenium at normal deposition conditions predominantly consists of an amorphous structure, which leads to a high recombination rate and a reduction in efficiency. The degree of amorphous component in selenium must be reduced to improve collection efficiency. The basic hypothesis is that by controlling the thickness and amorphous content of the selenium layer in a Se-ZnO heterojunction solar cell, we can attain conversion efficiency of 30% or above [15].

M. A. Mayer, D. T. Speaks, K. M. Yu, S. S. Mao, E. E. Haller and W. Walukiewicz, “Band structure engineering of ZnO(1-x)Se(x) alloys,” Applied Physics Letters, vol. 97, p. 220104, 2010.
A. Kaphle and P. Hari, “Enhancement in Power Conversion Efficiency of Silicon Solar Cells,” Thin Solid Films, vol. 657, pp. 76 – 87, 2018.
A. Kaphle, M. Borunda and P. Hari, “Influence of cobalt doping on residual stress in ZnO nanorods,” Materials in Semiconductor Processing, vol. 84, pp. 131 – 137, 2018.

Using Amino Acids on Metals as a Form of Biocatalyst to Understand Early Life (Dr. Iski)

With growing interest into origin of life studies as well as the advancement of medical research using nanostructured architectures, investigations into amino acid interactions have increased heavily in the field of surface science. Amino acid assembly on metallic surfaces is typically investigated with Scanning Tunneling Microscopy (STM) at low temperatures (LT) and under ultra-high vacuum (UHV), which can achieve the necessary resolution to study detailed molecular interactions and chiral templating. However, in only studying these systems at LT and UHV, results often tend to be uncertain when moving to more relevant temperatures and pressures. This investigation focuses on the Electrochemical STM (EC-STM) study of five simple amino acids (L-Valine, L-threonine, L-Isoleucine, L-Phenylalanine, and L-Tyrosine) as well as two modifications of a single amino acid (L-Isoleucine Ethyl Ester and N-Boc-L-Isoleucine), and the means by which these molecules interact with a Au(111) surface. By analyzing the results gathered via EC-STM at ambient conditions, fundamental insight can be gained into not only the behavior of these amino acids with varied side chains and the underlying surface, but also into the relevance of LT-UHV STM data as it compares to data taken in more realistic scenarios (1,2). This project will lead to a deeper understanding of how small, prebiotic molecules interact with surfaces and participate in the emergence of biologically applicable precursors. On a fundamental level, this project will study how amino acid molecules interact and how those interactions correlate to biologically relevant structures like proteins.

  • Using EC-STM to Obtain an Understanding of Amino Acid Adsorption on Au(111). Jesse A. Phillips, Kennedy P. Boyd*, Irene Baljak*, Lauren K. Harville*, Erin V. Iski. AIP Advances, 9, (2019), 105221-105233.
  • Formation of Magic Gold Fingers Under Mild and Relevant Experimental Conditions. Jesse A. Phillips, Kennedy P. Boyd*, Irene Baljak*, Lauren K. Harville*, Erin V. Iski. Sci., 687, (2019), 1-6.

Integration of Biosynthetic Pathways into Microalgae for Biofuels Production (Mentor Dr. Johannes)

A new approach for assembling and integrating multi-gene pathways into the nuclear genome of microalgae using CRISPR-Cas9 [16] is the focus of this project, which will study the assembly and integration of complex multi-gene biosynthetic pathways into the nuclear genome of the microalgae species Chlamydomonas reinhardtii.  The potential of algae-based biofuels [17] and protein therapeutics [18] is well documented, but in order to achieve its full potential, genetic engineering is needed to increase the production of target metabolites to desirable levels. Although recombinant protein expression in the microalgae has recently become more robust, the assembly and expression of complex multi-gene biosynthetic pathways in microalgae has yet to be fully accomplished and is a significant step in our ability to engineer microalgae metabolite production for the production of commercially important products [19], [20]. Thus we hypothesize that based on the successful development of similar methods in other species, an efficient nuclear multi-gene assembly and integration method can be developed co C. reinhardtii.  Biosynthetic pathways consisting of one to four genes will be assembled using homologous recombination in the yeast strain Saccharomyces cerevisiae and integrated into the C. reinhardtii nuclear genome using CRISPR-Cas9.  Multi-gene biosynthetic pathways of increasing complexity will be studied systematically. Pathways to be assembled include well studied selection markers and reporter genes and the biosynthetic pathway for the bioplastic polyhydroxybutyrate (PHB) [21]. Once integrated into the nucleus, the genetically engineered strains will be tested using a variety of methods to determine the levels of gene expression and the production level of PHB. The proposed project will provide important insights into the assembly and expression of biosynthetic pathways in microalgae and result in the development of an important tool for genetically modifying the nuclear genome of C. reinhardtii. These insights and the resulting methodology will aid current efforts to produce biofuels from microalgae, enhance our ability to produce therapeutic proteins in microalgae, and be an effective new tool for genetically engineering higher plants and other strains of microalgae.

[16] M. Jinek, K. Chylinski, I. Fonfara, M. Hauer, J. A. Doudna and E. Charpentier, “A programmabel dual-RNA-guided DNA endonuclease in adaptive bacterial immunity,” Science, vol. 337, pp. 816-821, 2012.
[17] M. K. Lam and K. T. Lee, “Microalgae biofuels: A critical review of issues, problems and the way forward,” Biotechnology Advances, vol. 30, pp. 673-690, 2012.
[18] B. A. Rasala, M. Muto , P. A. Lee, M. Jager, R. M. F. Cardoso, C. A. Behnke, P. Kirk, C. A. Hokanson, R. Crea, M. Mendez and S. P. Mayfield, “Production of therapeutic proteins in algae, analysis of expression of seven human proteins in the chloroplast of Chlamydomonas reinhardtii,” Plant Biotechnology, vol. 8, pp. 719-733, 2010.
[19] S. Noor-Mohammadi, A. Pourmir and T. Johannes, “Method for assembling and expressing multiple genes in the nucleus of microalgae,” Biotechnology Letters, vol. 36, pp. 561-566, 2014.
[20] S. Noor-Mohammadi, A. Pourmir and T. W. Johannes, “Methods to assemble and integrate biochemical pathways into the chloloplast genome of Chlamydomonas reinhardtii,” Biotechnology and Bioengineering, vol. 109, pp. 2896-2903, 2012.
[21] W. Chaogang, H. Zhangli, L. Anping and J. Baohui, “Biosynthesis of poly-3-hydroxybutrate (PHB) in the transgenic green alga Chlamydomonas reinhardtii,” Journal of Phycology, vol. 46, pp. 396-402, 2010.

Electrochemical Purification of Silicon from Abundant Silica Sources (Mentor Dr. LeBlanc)

While many new material systems are currently being explored for photovoltaic modules, silicon has long been the most widely adopted photovoltaic technology. Silicon has several advantages over newer material systems that have been the focus of much photovoltaics research. Beyond the well-established market performance of silicon based modules, the inherent advantages of abundance, ruggedness, and safety (over the operating life) position silicon based systems to remain a critical commercial photovoltaic technology for the foreseeable future. The process for generating solar grade silicon (99.9999% purity) requires several energy intensive and hazardous procedures, making the polysilicon material a significant contributor to the overall cost and energy payback time of the photovoltaic [16]. In this project we will explore a new electrochemical strategy to purify silicon from abundant silica sources using ionic liquids and liquid metal electrodes.

 

Figure 1. Schematic of the electrochemical liquid-liquid-solid growth method [17].

Recently, researchers have described an electrochemical liquid-liquid-solid (ec-LLS) growth method in which crystalline silicon was deposited and subsequently purified through the saturation of the product in a liquid-metal electrode [17]. This strategy takes advantage of the unique property of liquid gallium to partially solubilize silicon. This property means that the electrochemically deposited silicon undergoes a purification process akin to recrystallization. However, the current process cannot be used with a silica starting material due to solvent limitations. As a part of this project we will explore how the electrochemistry of gallium is affected by environment of an ionic liquid. The hypothesis of this work is that thermodynamically stable materials such as silica can be suspended in task-specific ionic liquid solvents based on electrostatic interactions while maintaining the necessary electrochemical stability to be processed using ec-LLS. By coupling the recent finding that ionic liquids can be used to solubilize SiO2 starting materials with the established ec-LLS growth method, we will demonstrate how high purity silicon can be produced at low costs, ultimately reducing the overall costs of silicon based photovoltaics.

[16] Mariska de Wild-Scholten, M. J. (2013). Energy payback time and carbon footprint of commercial photovoltaic systems. Solar Energy Materials and Solar Cells, 119, 296–305. https://doi.org/https://doi.org/10.1016/j.solmat.2013.08.037
[17] Gu, J., Fahrenkrug, E., & Maldonado, S. (2013). Direct electrodeposition of crystalline silicon at low temperatures. Journal of the American Chemical Society, 135(5), 1684–1687. https://doi.org/10.1021/ja310897r

Biochar-based Carbon-encapsulated Iron Nanoparticles (CEINPs) as Adsorbents for Contaminants in Wastewater (Mentor Dr. Ramsurn)

Carbon-based materials are preferred as a metal catalyst support, since they offer higher chemical and thermal stability as well as biocompatibility when compared to polymer or silica coatings [34].  The advantages of using carbon-materials as catalyst support also include lower cost than alumina or silica supports and resistance to the presence of oxygenated functional groups which may enhance metal adsorption and catalyst dispersion [35]. The economic value of biomass relies on the revenue of the products. Biochar is a carbon-rich solid product obtained after carbonization of biomass in hydrothermal media [36].  Research shows biochar obtained from different feedstocks was used for soil amendment to mitigate greenhouse gas emissions, as contaminant adsorbents and for the generation of heat and energy [37], [38]. The Ramsurn lab has successfully synthesized carbon-encapsulated iron nanoparticles (CEINPs) by carbonizing and impregnating biomass model compounds (cellulose, hemicellulose and lignin) [39]. Herein, we aim to test these CEINPs for their adsorption features and their ease of separation due to their magnetic properties. The objectives of this work will be to

  1. Identify the most common heavy metals (Cr, Ar, Cu) present in wastewater in the literature.
  2. Prepare solutions of the identified metals and generate calibration curves for the analytical instrument (UV-Vis and ICP-MS: it is proposed to compare the two methods).
  3. Test biomass derived activated carbon (without Fe) as a baseline.
  4. Repeat Objective 3 with the CEINPs. A number of parameters may be investigated: type of CEINPs [derived from lignin, cellulose or hemicellulose], amount of CEINPs, change in contaminant concentration, reaction time etc.

The hypothesis is that these CEINPs have a higher adsorption efficiency due to the graphitic layers formed around the Fe and they should easily come out of solution using a strong enough magnet.

[34] A. Taylor, Y. Krupskaya, S. Costa, S. Oswald, K. Kramer, S. Fussel, R. Klingeler, B. Buchner, E. Borowiak-Palen and M. P. Wirth, “Functionalization of carbon-encapsulated iron nanoparticles,” Journal of Nanoparticle Research, vol. 12, pp. 513-519, 2010.
[35] E. Lam and J. H. Luong, “Carbon materials as catalyst supports and catalysts in the transformation of biomass to fuels and chemicals,” ACS Catalysis, vol. 4, pp. 3393-3410, 2014.
[36] H. Ramsurn, S. Kumar and R. B. Gupta, “Enhancement of biochar gasification in alkali hydrothermal medium by passivation of inorganic components using Ca (OH) 2,” Energy & Fuels, vol. 2011, pp. 2389-2398, 2011.
[37] F. R. Amin, Y. Huang, Y. He, R. Zhang, G. Liu and C. Chen, “Biochar applications and modern techniques for characterization,” Clean Technologies and Environmental Policy, vol. 18, pp. 1457-1473, 2016.
[38] D. A. Laird, R. C. Brown, J. E. Amonette and J. Lehmann, “A review of the pyrolysis platform for coproducing bio-oil and biochar,” Biofuels, Bioproducts and Biorefining, vol. 3, pp. 547-562, 2009.
[39] S. T. Neeli and H. Ramsurn, “Synthesis and formation mechanism of iron nanoparticles in graphitized carbon matrix using biochar from biomass model compounds as a support,” Carbon, vol. 134, pp. 480-490, 2018.

Carbonization and densification of carbon-carbon composites for solar receivers (Dr Ramsurn)

This project aims at fabricating carbon-carbon composites as potential alternatives to metallic systems used in gas-phase Concentrating Solar Power (CSP) collectors.  C-C composites have extreme resistance to high temperatures and maintain mechanical properties with little change from room temperature up to almost 1800 °C and have high thermal conductivity.  This research will entail in preparing different prepregs (carbon fibers with resin with different number of layers and layering direction) and carbonizing and densifying these prepregs at different heating rates to achieve more efficient heat transfer and mechanical durability.

Sustainable Collector Alternatives for Mineral Flotation Applications (Mentor Dr. Weston)

Mineral, or ore, flotation is a separation technology used to selectively separate different minerals found in a mined ore sample before it is sent to be refined into metals. This separation process makes the mining of mixed ores economically feasible and less energy intensive. The process works by mixing ground ore particles with water to form a slurry. Certain ‘collector’ molecules are then added to the slurry to render the desired minerals more hydrophobic than others. The slurry is then added to the flotation tanks, which are aerated to produce bubbles. The hydrophobic particles attach to the surface of these air bubbles, which rise to the surface and form froth or foam layer. The froth is then removed from the cell producing a more concentrated stream of the desired mineral. This same separation technique is also used in waste water treatment and paper recycling to separate desirable products from undesirable or remove difficult to process materials from the stream. A large number of specialty chemicals have been developed to render different minerals hydrophobic, but many of these have undesirable environmental impacts. Developing and testing sustainable alternatives to these chemicals is necessary to ensure that ore processing can continue into the future and ensure that the metals necessary for modern electronics and other devices can be mined sustainably.