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Polyhydroxybutyrate Production In A Photobioreactor Using Spirulina Platensis, Adrianna Mika

Electronic Thesis and Dissertation Repository

Biopolymers and other naturally derived chemicals continue to gain attention over petrochemical based products due to the price volatility of crude oil, increasing need to reduce greenhouse gas emissions and public awareness of environmental issues. Cyanobacterium Spirulina (Arthrospira) platensis, a commercially feasible blue-green alga, is able to synthesize poly(3-hydroxybutyrate) (PHB), a biodegradable and biocompatible polymer, as an energy storage product of photosynthesis directly from CO₂. A flat plate photobioreactor (PBR) with LED illumination was designed for the cultivation of S. platensis. Computational fluid dynamics (CFD) software was used to improve airflow uniformity and mixing in the …

Engineering, Nutrient Removal, And Feedstock Conversion Evaluations Of Four Corn Stover Harvest Scenarios, Reed L. Hoskinson, Douglas L. Karlen, Stuart J. Birrell, Corey W. Radtke, W. W. Wilhelm

Douglas L Karlen

Crop residue has been identified as a near-term source of biomass for renewable fuel, heat, power, chemicals and other bio-materials. A prototype one-pass harvest system was used to collect residue samples from a corn (Zea mays L.) field near Ames, IA. Four harvest scenarios (low cut, high-cut top, high-cut bottom, and normal cut) were evaluated and are expressed as collected stover harvest indices (CSHI). High-cut top and high-cut bottom samples were obtained from the same plot in separate operations. Chemical composition, dilute acid pretreatment response, ethanol conversion yield and efficiency, and thermochemical conversion for each scenario were determined. Mean grain …

Targeted Products From Fast-Hydropyrolysis And Hydrodeoxygenation Of Biomass, Ian Tad Smith

Open Access Theses

Previously, the H2Bioil process was proposed as a possible way to convert sustainably available intact biomass into liquid fuels. The optimization of this process and possible synergies with other biomass conversion processes are presented in this thesis.

The selectivity of the PtMo hydrodeoxygenation catalyst was tuned using two different hydrogen partial pressures: 25 bar, and 2.5 bar. This effect was studied on cellulose and intact biomass samples to determine the effect that hydrogen has upon the retention of aromatic compounds found in intact biomass. These experiments show that it is possible for the hydrogenation activity of the PtMo catalyst to …

Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts

Master's Theses

Microalgae can be grown on municipal wastewater media to both treat the wastewater and produce feedstock for algae biofuel production. However the reliability of treatment must be demonstrated, as well as high areal algae productivity on recycled wastewater media and efficient sedimentation harvesting. This processes was studied at pilot scale in the present research.

A pilot facility was operated with nine CO₂-supplemented raceway ponds, each with a 33-m² surface area and a 0.3-m depth, continuously from March 6, 2013 through September 24, 2014. The ponds were operated as three sets of triplicates with two sets continuously fed …

Pyrolysis Based Biorefineries For The Production Of Fermentable Substrates, Luis Carlos Luque-Moreno

Electronic Thesis and Dissertation Repository

Fast pyrolysis is rapid thermal conversion process capable of transforming multiple feedstocks into various energy carriers, specifically pyrolysis oil, bio gas, and bio char. The oil phase is of high value due to its complex mixtures of organic molecules, along with large number of anhydrous carbohydrates, which can be easily transformed into glucose via acid hydrolysis. These carbohydrates can be either biocatalyzed into fuels and chemicals by microorganisms or converted after further treatment steps. However quantities of these carbohydrates in the oil are a function of feedstock composition and process parameters. The research presented in this thesis focuses on producing …

Design Of Transgenic S. Cerevisiae For Enzymatic Pretreatment, Mark Aronson, Leyla Yamin, Soo Jung Ha, Jenna Rickus, Michael E. Scharf

The Summer Undergraduate Research Fellowship (SURF) Symposium

Biofuels, combustible fuel produced from fermentation of agricultural biomass by microorganisms, represent one of the best possible paths forward for sustainable energy production. However, inefficiencies in biofuel production create barriers that stand in the way of their widespread adoption. One such barrier is the breakdown of lignin, a biopolymer that exists on the edge of plant cell walls which protects the sugars that are used in fermentation. Currently, lignin is broken down in energy-intensive thermal pretreatment processes. A viable alternative is the expression of lignin-degrading enzymes by synthetic microorganisms that work at standard temperatures, eliminating the need for the high-energy …

The Effects Of Volatile Fatty Acids On The Performance Of Microbial Electrolysis Cells, Nan Yang

Electronic Thesis and Dissertation Repository

This study investigated the performance of microbial electrolysis cells (MECs) fed with three common fermentation products: acetate, butyrate, and propionate. Each substrate was fed to the reactor for three consecutive-batch cycles. The results showed high current densities for acetate, but low current densities for butyrate and propionate (maximum values were 6.0 ± 0.28, 2.5 ± 0.06, 1.6 ± 0.14 A/m², respectively). Acetate also showed a higher coulombic efficiency of 87 ± 5.7 % compared to 72 ± 2.0 and 51 ± 6.4 % for butyrate and propionate, respectively. This paper also revealed that acetate could be easily oxidized …

Production Of Activated Carbons From Pyrolytic Char For Environmental Applications, Anastasia Colomba

Electronic Thesis and Dissertation Repository

Biomass pyrolysis has the potential to become a major component of future biorefineries, since biomass is cracked to produce gases, liquid products (bio-oil) and solid products (bio-char). In order for the process to be economically feasible, it is necessary to obtain the maximum value from each stream, thus no by-product can be regarded as a waste.

Bio-char is normally regarded as a by-product of fast pyrolysis, which is optimized to target bio-oil production. However, there are many potentially attractive applications for it: for example, it can be used for the production of activated carbons, which are the most commonly used …

Competence Evaluation Of Mycodiesel Production By Oleaginous Fungal Strains: Mucor Circinelloides And Gliocladium Roseum, Sandip S. Magdum, Gauri P. Minde, Upendra S. Adhyapak, V. Kalyanraman

Sandip S. Magdum

Comparing with lesser algal growth rate for biofuel production along with many constraints, fungal route should be analyzed for its capability of biodiesel or mycodiesel production. The two fungal strains namely, Mucor circinelloides (MTCC1297) and Gliocladium roseum (MTCC6474) were analyzed for laboratory scale mycodiesel production. The M. circinelloides and G. roseum were able to produce biomass of 0.404 mg VSS/mg sucrose and 0.642 mg VSS/ mg sucrose with the mycodiesel content of 20.69% (w/w) and 11.37% (w/w) respectively. Furthermore, qualitative analysis of the oil contents by GC-MS were identified the presence of Tetradecanoic and Octadecanoic acids.

Estimates Of Biomass And Fixed Carbon At A Rainforest In Panama, Reinhardt Pinzón, José Fábrega, David Vega, Erick N. Vallester, Rafael Aizprúa, Francisco R. López-Serrano, Fred Ogden, Kleveer Espino

Fred L. Ogden

This paper presents an estimation of the quantity of carbon fixed in trees in a one hectare (ha) plot at the Cerro Pelado-Gamboa Hydrology Tropical Observatory, which is located in the province of Colon, Panama. The estimation of carbon fixed in trees may provide significant information on carbon flux due to water circulation, which may ultimately enable evaluation of the carbon cycle. All trees larger than 10 cm diameter at breast height (DBH) in the plot were investigated. Carbon fixed within these trees was estimated using a parameterized formula. Tree biomass estimations for the plot were 97.21 Mg ha -1. …

Effects Of Biomass Moisture Content On Volatile Flame Length During Cofiring With Coal, Matthew Pollard

McKelvey School of Engineering Theses & Dissertations

Cofiring biomass with coal can contribute to meeting Renewable Portfolio Standards (RPS) and reduce pollutant emissions. The physical characteristics and composition of biomass can vary significantly, which can affect the combustion characteristics. When cofiring biomass with coal, these differences can impact the structure of the volatile flame, the region where combustion of volatiles dominates. The length and location of the volatile flame is important to flame stability and determines the location and extent of volatile release. This has an effect on pollutant emissions, such as NOx (nitrogen oxides). Previously, the effects of parameters such as cofiring ratio, particle size, and …

A Study On The Be2100 Noninvasive Biomass Sensor As An Instrument For Measuring Optical Density During Fed-Batch Fermentation At Various Stir Rates, Hannah Moreland

Biological and Agricultural Engineering Undergraduate Honors Theses

Fusion proteins, engineered proteins that combine the DNA sequences and therefore properties of two different proteins, can be used in a variety of therapeutic purposes. One example of a therapeutic fusion protein is collagen binding domain-parathyroid hormone glutathione-S-transferase (CBD-PTH-GST), which can combat osteoporosis by binding specifically to collagen in the vertebral column and promoting bone growth through the release of calcium. This fusion protein is being expressed with Escherichia coli at the University of Arkansas through fed-batch fermentation, a method that produces large volume of cells through fermentation in a controlled environment in a bioreactor. It is necessary to track …

Non-Catalytic Co-Gasification Of Sub-Bituminous Coal And Biomass, Guevara Che Nyendu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Utilization of coal as a low-cost domestic energy source is becoming a subject of utmost importance due to fluctuating crude oil prices. However, coal use emits pollutants such as nitrous oxides (NO_x), sulfur oxides (SO_x), carbon dioxide (CO₂), and particulates that have negative environmental impact and significant issues on health. To minimize the harmful effects of coal use, renewable and sustainable biological or green materials called biomass are processed with coal to produce synthetic gas (syngas) that can be processed into clean energy fuels and value-added products.

Currently, coal is converted using combustion technology; …

Structural Evolution Of Molybdenum Carbides In Hot Aqueous Environments And Impact On Low-Temperature Hydroprocessing Of Acetic Acid, Jae-Soon Choi, Viviane Schwartz, Eduardo Santillan-Jimenez, Mark Crocker, Samuel A. Lewis Jr., Michael J. Lance, Harry M. Meyer Iii, Karren L. More

Center for Applied Energy Research Faculty and Staff Publications

We investigated the structural evolution of molybdenum carbides subjected to hot aqueous environments and their catalytic performance in low-temperature hydroprocessing of acetic acid. While bulk structures of Mo carbides were maintained after aging in hot liquid water, a portion of carbidic Mo sites were converted to oxidic sites. Water aging also induced changes to the non-carbidic carbon deposited during carbide synthesis and increased surface roughness, which in turn affected carbide pore volume and surface area. The extent of these structural changes was sensitive to the initial carbide structure and was lower under actual hydroprocessing conditions indicating the possibility of further …

In-Situ Catalytic Upgrading Of Biomass Pyrolysis Vapor: Co-Feeding With Methanol In A Multi-Zone Fixed Bed Reactor

Faculty of Engineering University of Malaya

The in-situ catalytic upgrading of the biomass pyrolysis vapor and its mixture with methanol were conducted in a fixed bed multi-zone reactor. The steps were comprised; thermally converting the biomass in the pyrolysis reactor, passing its vapor in contact with the HZSM-5 zeolite catalyst in the presence of methanol vapor, and transformation of the resulting upgraded pyrolysis vapor into the liquid product. The biomass pyrolysis and catalytic pyrolysis vapor upgrading were performed at 500 degrees C. The highly valuable chemicals production was a function of the hydrogen to carbon effective ratio (H/C-eff) of the feed. This ratio was regulated by …

Effect Of Microwave Frequency On Dielectric Properties Of Oil Palm Shell (Ops) And Ops Char Synthesized By Microwave Pyrolysis Of Ops

Faculty of Engineering University of Malaya

Microwave heating is considered to be a potential, efficient and fast method for thermal treatment of biomass. Therefore, elemental understanding of dielectric properties of biomass is necessary before irradiating it with microwave radiations. Dielectric properties along with penetration depth, relaxation time and static permittivity of oil palm shell COPS) and OPS char were investigated in the frequency ranging between 0.5 and 20 GHz at room temperature. At low frequencies, dielectric constant of UPS was higher than that of UPS char while at higher frequencies, vice versa is observed. Penetration depth for UPS char was higher than that of UPS at …

The Bifunctional Alcohol And Aldehyde Dehydrogenase Gene, Adhe, Is Necessary For Ethanol Production In Clostridium Thermocellum And Thermoanaerobacterium Saccharolyticum, Jonathan Lo, Tianyong Zheng, Shuen Hon, Daniel G. Olson, Lee Lynd

Dartmouth Scholarship

Thermoanaerobacterium saccharolyticum and Clostridium thermocellum are anaerobic thermophilic bacteria being investigated for their ability to produce biofuels from plant biomass. The bifunctional alcohol and aldehyde dehydrogenase gene, adhE, is present in these bacteria and has been known to be important for ethanol formation in other anaerobic alcohol producers. This study explores the inactivation of the adhE gene in C. thermocellum and T. saccharolyticum. Deletion of adhE reduced ethanol production by >95% in both T. saccharolyticum and C. thermocellum, confirming that adhE is necessary for ethanol formation in both organisms. In both adhE deletion strains, fermentation products shifted from ethanol …

Determining Soil Erosion With Varying Corn Stover Cover Factors, Nicole K. Koeninger

Theses and Dissertations--Biosystems and Agricultural Engineering

Since the Dust Bowl, conservation agriculture has become a common practice globally. Because of the rising interest in the use of corn biomass as a feedstock for biofuel production, the effects of corn stover removal on soil erosion were explored. It was hypothesized that selective harvesting strategies would impact soil erosion differently across a variety of slopes. Soil erosion boxes were constructed, and a rainfall simulator with an intensity of 30 mm hr^-1 for 46 min was used to create runoff from slopes of 1, 5, and 10% and three cover factor treatments (no removal and two simulated corn …

Characterization Of Two Biochars Derived From Horse Muck And Their Ability To Reduce Pathogen Transport In Soil, David Griffith

Theses and Dissertations--Biosystems and Agricultural Engineering

Biochars have been created and characterized from a variety livestock manure biomass including poultry, dairy, and swine. However, no research has been conducted on the physical and chemical makeup of biochar pyrolyzed from horse muck. Two horse muck derived biochars containing either straw (HS) or woodchip (HW) bedding were pyrolyzed at 700°C and characterized for their physical and chemical properties. Tests revealed both biochars had high alkalinity, moderate specific conductivity, and low surface area as compared to other biochars in the literature. HS contained more mineral structures than HW. Scanning electron microscopy presented differences in particle shape, size, and presence …