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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 …

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 …

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 …

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 …

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; …

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 …

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 …

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 …