Physical Sciences and Mathematics Commons^™

Allocation Of U.S. Biomass Production To Food, Feed, Fiber, Fuel And Exports, Christopher L. Lant, Suman Paudel, Kaeli Mueller, Grace Larson, Gustavo A. Ovando-Montejo, Jennifer E. Givens

Environment and Society Faculty Publications

This paper analyzes the end uses—food, feed, fiber, fuel, and exports—of biomass production in the U.S. in 1997, 2002, 2007, and 2012. They are also analyzed at the state level in 2012. Biomass production is measured as human appropriation of net primary production (HANPP), an ecological footprint measured as carbon fixed through photosynthesis, derived from data on crop, timber and grazing yields. HANPP was allocated to end uses using publicly available sources from the U.S. Department of Agriculture and internet-based sources publishing data on agricultural trade. HANPP was 717–834 megatons (MT) of carbon per year, which comprised 515–615 MT of …

Human Appropriation Of Net Primary Production Through Crops, Grazing, And Forestry In The U.S. From 1997 To 2012, Suman Paudel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation conducts a county-level analysis of human appropriation of net primary production (HANPP) harvested from crops, timber and grazing in the conterminous United States in the years 1997, 2002, 2007 and 2012. This study consists of three manuscripts (Chapters 2, 3, and 4). The first study quantifies net primary production in US counties in 1997, 2002, 2007 and 2012. The detailed HANPP study conducted concludes that HANPP is a valuable footprint tool for analyzing land use intensity and agricultural ecosystems. The second manuscript shows how HANPP is an improved or modernized ecological footprint and is a sustainable indicator as …

Multi-Criteria Evaluation Model For Classifying Marginal Cropland In Nebraska Using Historical Crop Yield And Biophysical Characteristics, Andrew Laws

School of Natural Resources: Dissertations, Theses, and Student Research

Marginal cropland is suboptimal due to historically low and variable productivity and limiting biophysical characteristics. To support future agricultural management and policy decisions in Nebraska, U.S.A, it is important to understand where cropland is marginal for its two most economically important crops: corn (Zea mays) and soybean (Glycine max). As corn and soybean are frequently planted in a crop rotation, it is important to consider if there is a relationship with cropland marginality. Based on the current literature, there exists a need for a flexible yet robust methodology for identifying marginal land at different scales, which …

Catalytic Activity Of Molybdenum-Dioxo Complexes, Randy Tran

Graduate Theses and Dissertations

This dissertation details the development of rationally designed dioxomolybdenum catalyst active for deoxydehydration (DODH), the net reduction of diols and polyols into alkenes and dienes. Catalyst design involved variations on dioxomolybdenum(VI) supported by a dianionic meridional pincer ligand. Rational substrate scope was explored using aliphatic diols, aromatic diols, and biomass derived diols. Various reductants were tested for ability to catalyze the reaction. The substrate specific mechanism of DODH was explored utilizing NMR and in-situ infrared spectroscopy and important rate constants and rate determining steps were found to aid in the optimization of ideal reaction conditions. Catalytic activity was observed to …

Switchgrass For Biomass Production, Monroe Rasnake, D. Parrish, Garry D. Lacefield, D. Wolf

IGC Proceedings (1997-2023)

Six cultivars of switchgrass (Panicum virgatum) were established in 1993 at Princeton, Kentucky, USA. Two harvest systems were used: two cuttings per year in mid-June and November and one cutting per year in November. Biomass yield and stand survival were evaluated. Lowland cultivars produced more biomass than upland cultivars in both cutting managements. Upland cultivars did better in a two cut system while the other cultivars showed little difference. Excellent stands of all cultivars were maintained under both cutting managements.

Investigation Of Techniques And Their Application For The Cryopreservation Of Algal Species, Jazmine Leija

Theses and Dissertations

An alternative source for petroleum-based crude oils are algae derived biofuels. Fossil fuels are harmful for the environment, expensive and becoming scarce. There has been an increase in research on environmentally sustainable energy, using lipids derived from microalgae, which can be converted into biofuel. The use of microalgae as a source for biofuels has a lot of benefits including decreasing greenhouse gas emissions, rapid fuel production, absorption of carbon dioxide, and production of a renewable source of energy.

Algae cryopreservation aids in the maintenance of the best algae strains selected for producing lipids for biofuels. Cryopreservation will help minimize genetic …

Biorenewable Energy: New Opportunities For Grassland Agriculture, Kenneth J. Moore, Steven L. Fales, Emily A. Heaton

IGC Proceedings (1997-2023)

No abstract provided.

A Foray Into Laboratory Scale Soil Incubations With Corn Stover And High Lignin Fermentation Byproduct, Michelle Wang

ENGS 88 Honors Thesis (AB Students)

As the production of biofuels increases to meet the demands of a growing low carbon economy, questions of sustainability surrounding its feedstock and waste streams have become increasingly relevant. In the biofuel production process, crop residues like corn stover are harvested from the field and converted to biofuels leaving generating a residue called high lignin fermentation byproduct (HLFB). From extensive process modelling in the literature, it is suggested that HLFB should be either combusted to fuel auxiliary conversion processes or returned to the soil in place of the crop residues that were harvested. Currently, there is little literature testing the …

Nsf Career Award Supports Schwartz's Research On The Chemical Process For Making Rubber Component, Marcus Wolf

General University of Maine Publications

advance his ongoing dissection of the Lebedev process. The well-known, multi-step chemical reaction is used to make butadiene from biomass-derived ethanol. However, little research has been conducted on the Lebedev process at the molecular level. Understanding the intricacies of this process will help researchers create new catalysts necessary for the chemical reactions to make goods from both petroleum and biomass, that would increase butadiene yield.

Development Of Novel Membranes For Nanocarbon Enhanced Separation With Application In Biofuels And Solvent Recover, Oindrila Gupta

Dissertations

Pharmaceutical industries historically have had one of the highest amounts of solvent waste generated per unit of drug manufactured. Energy requirements and carbon footprint of current solvent recycling processes tend to be quite high, and the incineration of the solvents for waste disposal produces toxic air emissions. Also, rapidly increasing demand for energy and strict regulation on engine pollutant emissions have necessitated the use of alcohol as carbon-neutral fuels. Thermal distillation is one of the most common methods for the separation of alcohol-water mixtures. However, its application is limited due to energy requirements and high operating costs, and heating to …

Nutrient Recycling From Aqueous For Nitrogen Supplementation In Algae Growth, Alyssa Young

ELAIA

Algae-derived biofuels have the potential to become a source of renewable liquid fuel via hydrothermal liquefaction. However, for algal biofuels to be economically and environmentally feasible, sustainable nutrient recycling must be achieved. Desmodesmus armatus is a microalga to be used in hydrothermal liquefaction, but it is not yet known if the aqueous product waste from the biofuel production process can be recycled as a nitrogen source to support the growth of subsequent cultures of D. armatus. Here, aqueous product was treated with a Dowex 50WX8 resin for twenty-four hours. Growth media was prepared with treated and untreated aqueous product …

Effects Of Temperature And Antioxidants On The Oxidation Of Biodiesel Derived From Waste Vegetable Oil, Randy L. Maglinao, Torrey J. Wagner, Keegan Duff

Faculty Publications

Biodiesel offers several environmental benefits and improvements to some fuel performance properties, but its poor oxidative stability has been a major concern. Currently, the accepted practice to improve biodiesel oxidative stability is the addition of antioxidants; numerous antioxidants have been studied but their effectiveness in inhibiting biodiesel oxidation is difficult to predict due to variation with resonance stability, solubility, reactivity, and volatility. To improve prediction efforts, this study explored the Rapid Small-Scale Oxidation Test (RSSOT) as a means to investigate how biodiesel oxidation is affected by antioxidant concentration and temperature, and compared its results with the oxidative stability index test. …

Enhancing Digestibility And Ethanol Yield Of Populus Wood Via Expression Of An Engineered Monolignol 4-O-Methyltransferase, Yuanheng Cai, Kewei Zhang, Hoon Kim, Guichuan Hou, Xuebin Zhang, Huijun Yang, Huan Feng, Lisa Miller, John Ralph, Chang-Jun Liu

Huan Feng

Producing cellulosic biofuels and bio-based chemicals from woody biomass is impeded by the presence of lignin polymer in the plant cell wall. Manipulating the monolignol biosynthetic pathway offers a promising approach to improved processability, but often impairs plant growth and development. Here, we show that expressing an engineered 4-O-methyltransferase that chemically modifies the phenolic moiety of lignin monomeric precursors, thus preventing their incorporation into the lignin polymer, substantially alters hybrid aspens’ lignin content and structure. Woody biomass derived from the transgenic aspens shows a 62% increase in the release of simple sugars and up to a 49% increase in the …

Characterizing The Effects Of Environmental Stressors On The Photosynthetic Capacity Of Chlorella Vulgaris, Amanda Louise Smythers

Theses, Dissertations and Capstones

Chlorella vulgaris is a unicellular green algae grown throughout the world. Due to its multiple trophic modes as well as its ability to maintain high rates of growth under adverse conditions, it has been of global interest for use in ecological contamination studies, biofuel feedstock optimization, and studies of photosynthetic electron transfer. Using a wide-range of methods for physiological and photosynthetic characterization, the studies within seek to further extend the usefulness of C. vulgaris in a variety of environmentally important studies. Once the protocols were optimized specifically for this alga, they could be applied in both ecologically relevant and biodiesel …

Application Of Agent-Based Modeling To Complex Systems, Robert J. Zupko Ii

Dissertations, Master's Theses and Master's Reports

This dissertation examines the application of agent-based modeling (ABM) to complex systems with the intent of developing a means of overcoming limitations present in existing tools. This is done though the development of two ABMs intended to address complex systems present in the fields of sustainability studies and chemistry.

After introductory information, Chapters 2 - 4 of this dissertation address the limitations of tools intended to project the environmental, economic, and social impacts of woody biomass based biofuels. Chapter 2 begins by discussing the limitations in tools to study timber harvest decision making and its impact upon the landscape, and …

The Investigation And Characterization Of The Reaction Of 2-Methylfuran And 2-Methyl-3-Buten-2-Ol With O(3p) And The Photodissociation Of Xylyl Bromide Isomers, Yasmin Fathi

Master's Theses

This thesis has studied the oxidation behavior of different biofuels or additives, 2-methyl-3-buten-2-ol and 2-methylfuran, in combustion experiments at the Chemical Dynamics Beamline held at the Advanced Light Source of the Lawrence Berkley National Laboratory. The oxidation of these fuels were initiated through O(³P) and the combustion experiments were analyzed using a multiplexed chemical kinetics photoionization mass spectrometer with tunable synchrotron radiation. Products of the different reactions were identified using kinetic profiles and further characterized using the photoionization spectra. The amount of each species was calculated using branching fractions.

Additionally, the unimolecular dissociation of the xylyl bromide isomers …

Hydrogen Molybdenum Bronze Catalyzed Hydrolysis Of Cellulose, Claire O. Baker

Undergraduate Honors Theses

In recent years, there has been increasing concern with respect to the large dependence across the globe on nonrenewable energy sources, such as fossil fuels. Ethanol has been explored, however, in alleviating this problem; cellulose, a polymer of glucose molecules, is a precursor to this potentially useful biofuel. However, the strength and rigidity of the cellulose structure has proven to be a difficult obstacle to overcome in this multistep synthesis. Harsh conditions are required, often including concentrated sulfuric acid and extremely high temperatures, to complete hydrolysis to a useful extent. In this work, the hydrolysis of cellulose was performed with …

Strategies For The Production Of Cell Wall-Deconstructing Enzymes In Lignocellulosic Biomass And Their Utilization For Biofuel Production, Sang-Hyuck Park, Rebecca Garlock Ong, Mariam Sticklen

Rebecca Ong

Microbial cell wall-deconstructing enzymes are widely used in the food, wine, pulp and paper, textile, and detergent industries and will be heavily utilized by cellulosic biorefineries in the production of fuels and chemicals. Due to their ability to use freely available solar energy, genetically engineered bioenergy crops provide an attractive alternative to microbial bioreactors for the production of cell wall-deconstructing enzymes. This review article summarizes the efforts made within the last decade on the production of cell wall-deconstructing enzymes in planta for use in the deconstruction of lignocellulosic biomass. A number of strategies have been employed to increase enzyme yields …

Monitoring And Mitigation Of Elevated Co2 Impacts Using Microalgae, Terry-Rene Wiesner Brown

USF Tampa Graduate Theses and Dissertations

Climate change is arguably the greatest environmental and economic challenge of our time. There are considerable documented and projected impacts to both human and natural systems as a result of climate change. These impacts include changes in temperature, sea level, precipitation patterns, and biogeography of ecologically and economically relevant species, including pathogens. One of the main drivers of climate change is elevated levels of atmospheric carbon dioxide (CO₂), a greenhouse gas. Since pre-industrial times, atmospheric CO₂ levels have increased from approximately 280 ppm to over 400 ppm, as a result of fossil fuel combustion, cement production and …

Enhancing Algal Biomass And Lipid Production Through Bacterial And Fungal Co-Culture, Erwin David Berthold

FIU Electronic Theses and Dissertations

This thesis investigates the effects of co-culturing microorganisms including 37 yeast, 38 bacteria, nine diazotrophic cyanobacteria, and three fungi on biomass and lipid production in fresh- and saltwater algae. Algal lipid content was measured using Nile Red method and gravimetric techniques. Among the algal strains tested, freshwater Coelastrum sp. 46-4, and saltwater Cricosphaera sp. 146-2-9, showed enhanced biomass yield and lipid content in response to co-culture with bacteria, cyanobacteria, and fungi. While co-culture with yeast caused inhibition of algal productivity, no difference in algal productivity was observed between nitrogen-free diazotrophic cyanobacterial co-culture and nitrogen-replete monoalgal culture. Results indicated that extracellular …

Enhancing Digestibility And Ethanol Yield Of Populus Wood Via Expression Of An Engineered Monolignol 4-O-Methyltransferase, Yuanheng Cai, Kewei Zhang, Hoon Kim, Guichuan Hou, Xuebin Zhang, Huijun Yang, Huan Feng, Lisa Miller, John Ralph, Chang-Jun Liu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Producing cellulosic biofuels and bio-based chemicals from woody biomass is impeded by the presence of lignin polymer in the plant cell wall. Manipulating the monolignol biosynthetic pathway offers a promising approach to improved processability, but often impairs plant growth and development. Here, we show that expressing an engineered 4-O-methyltransferase that chemically modifies the phenolic moiety of lignin monomeric precursors, thus preventing their incorporation into the lignin polymer, substantially alters hybrid aspens’ lignin content and structure. Woody biomass derived from the transgenic aspens shows a 62% increase in the release of simple sugars and up to a 49% increase in the …

Algal Wastewater Treatment And Biofuel Production: An Assessment Of Measurement Methods, And Impact Of Nutrient Availability And Species Composition, John F. Chamberlin

Graduate Theses and Dissertations

In order to move towards a more sustainable future, human civilization will need to decrease its impacts on air and water quality and minimize consumption of fossil fuels. Using algae for wastewater treatment and biofuel production offers one approach to progress towards these goals simultaneously. Algae are capable of removing nutrients from wastewater and carbon dioxide from the air, and the biomass formed in that process can be used to generate a wide-range of products including fertilizer or fuels that could power combustion engines, power plants, or zero-emission fuel cell vehicles. Using wastewater for biofuel production has the potential to …

Lipid Content And Biomass Analysis In Autotrophic And Heterotrophic Algal Species, Addie M. Lauder, Daniel P. Jones, Thomas E. Walker, Todd Allen

Montview Journal of Research & Scholarship

Biofuels are a form of renewable energy derived from living matter, typically plants. The push for biofuels began in order to decrease the amount of carbon dioxide (CO2) released into the atmosphere, as biofuels are essentially carbon neutral. The idea is the same amount of CO2 the plants took in to perform photosynthesis will then be released in the burning of the biofuels. Algae is an excellent source of biofuels because it grows quickly and is versatile in terms of the type of fuel it can produce. The two most common mechanisms for algae growth are heterotrophic or photoautotrophic. Heterotrophically …

Parametric Analysis Of A Solid Oxide Fuel Cell Auxiliary Power Unit Operating On Syngas Produced By Autothermal Reforming Of Hydrocarbon Fuels, Jun Dong, Xinhai Xu, Ben Xu, Shuyang Zhang

Mechanical Engineering Faculty Publications and Presentations

A 1 kWe integrated auxiliary power unit (APU) system consisting of an autothermal reformer and a solid oxide fuel cell (SOFC) unit, as well as balance-of-plant components, was designed and analyzed. A relatively easy-to-approach SOFC model was developed in order to conveniently calculate V-I and P-I curves and the system's net efficiency at different operating conditions. The effects of steam to carbon and oxygen to carbon ratios in the reactants, channel dimensions of the SOFC unit, and hydrocarbon fuel types on the integrated APU system's performance were discussed. Five hydrocarbon fuels including diesel, Jet-A, gasoline, ethanol, and methanol were studied …

Biological Lignocellulose Solubilization: Comparative Evaluation Of Biocatalysts And Enhancement Via Cotreatment, Julie M. D. Paye, Anna Guseva, Sarah K. Hammer, Erica Gjersing

Dartmouth Scholarship

Feedstock recalcitrance is the most important barrier impeding cost-effective production of cellulosic biofuels. Pioneer commercial cellulosic ethanol facilities employ thermochemical pretreatment and addition of fungal cellulase, reflecting the main research emphasis in the field. However, it has been suggested that it may be possible to process cellulosic biomass without thermochemical pretreatment using thermophilic, cellulolytic bacteria. To further explore this idea, we examine the ability of various biocatalysts to solubilize autoclaved but otherwise unpretreated cellulosic biomass under controlled but not industrial conditions.

Minimizing Environmental Impacts For Hub And Spoke Distribution Network Problems Through The Use Of Multi-Objective Evolutionary Algorithms, Ileana Delgado

Open Access Theses & Dissertations

While transportation is crucial to our economy and our personal lives, as a sector it is also a significant source of greenhouse gas (GHG) emissions. The AASHTO report states, "America's transportation system has served us well, but now faces the challenges of congestion, energy supply, environmental impacts, climate change, and threatens the economic, social, and environmental future of the nation". With respect to the environment, transportation is the most visible aspect of supply chains. Transportation emissions can be reduced by implementing approaches that contribute to GHG emissions reduction, for example, the use of low-carbon fuels, new and improved vehicle technologies, …

Resolving The Policy Paradox: The Case Of Biofuel Production In Ireland, Alan Gilmer, Mark J. Mcgarrity, Vivienne Byers

Articles

Purpose – The purpose of this paper is to determine the status of policy design and policy implementation in the biofuel sector in Ireland. The focus of the work addresses the overarching operational context of the biofuel sector in Ireland and the role of different actors in shaping and resolving inconsistencies in policy outlook and practice. Design/methodology/approach – This study used a qualitative research approach involving a series of semi-structured interviews with members of the relevant sub-groups concerned. This study sought to address two questions – whether current or proposed policy is likely to affect consumption of indigenous biofuel feedstocks …

Comparing Nutrient Recovery Via Rapid (Flash Hydrolysis) And Conventional Hydrothermal Liquefaction Processes For Microalgae Cultivation, Caleb Richard Talbot

Civil & Environmental Engineering Theses & Dissertations

Algal biofuels have the potential to provide a scalable source of renewable fuels in the near future. The high nutrient use in algae cultivation and its recovery and recycling is one of the challenges that may limit the scalability and sustainability of algal biofuels. The present study evaluates the use of Hydrolysate obtained after Flash Hydrolysis (FH) of Scenedesmus at 280 C as a nutrient source for microalgae cultivation. FH Hydrolysate nutrient recycling was compared with low temperature batch Hydrothermal Liquefaction (HTL) nutrient recycling. Oocystis and Scenedesmus were cultivated using Hydrolysate as a partial phosphorous (P) and nitrogen (N) source. …

Furanic Molecules: Multiplexed Synchrotron Photoionization Investigations And Aerosol Studies, Audrey R. Smith

Master's Theses

The oxidation reactions of 2-methylfuran (2MF) and 2-ethylfuran (2EF) initiated by Cl radicals is studied at the low temperatures, in addition to the determination of the absolute photoionization cross-sections of 2EF, 2-acetylfuran, and furfural. These experiments are carried out using synchrotron photoionization mass spectrometry (SPIMS) with an orthogonal time-of-flight spectrometer used for mass analysis at the Advanced Light Source of Lawrence Berkeley National Laboratory. CBS-QB3 calculated adiabatic ionization energies (AIE) agree well with the experimental results and published literature values. Furfural is found to be the dominant product of 2MF oxidation, with 2-acetylfuran and 2-vinylfuran being the dominant products of …

Three Essays On Biofuels, Drought, Livestock, And The Environment, Sunil P. Dhoubhadel

Department of Agricultural Economics: Dissertations, Theses, and Student Research

This dissertation consists of three essays. The first essay examines the impact of the 2012 drought and the biofuels mandate on the U.S. grain and livestock markets. A stochastic equilibrium displacement model is used to analyze the impact on eight commodity markets viz. beef, pork, poultry, corn, distillers’ grain (DG), soybean, soymeal, and ethanol. Among the eight markets, corn and beef are found to be the most vulnerable to drought. The use of Renewable Identification Number (RIN) credits as an instrument to mitigate the impact of drought has limited effectiveness. A mandate waiver of about 23% is required to fully …