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Switchgrass Extractives Have Potential As A Value-Added Antimicrobial Against Plant Pathogens And Foodborne Pathogens, Alexander Ian Bruce

Masters Theses

Panicum virgatum (switchgrass), a perennial grass native to North America, is a leading biomass feedstock candidate for the manufacture of cellulosic ethanol. Switchgrass is considered a viable option for biofuel production due to its cheap production cost and ability to grow on marginal land. Biofuel derived from switchgrass has been shown to be very energy efficient, producing 540% more renewable energy versus nonrenewable energy expended. Switchgrass-derived biofuel is also estimated to have greenhouse gas emissions that are 94% lower than emissions from gasoline (Schmer et al 2008). Biofuels are created through biochemical processes that utilize various enzymes and microorganisms for …

Modification Of Carbohydrate Active Enzymes In Switchgrass (Panicum Virgatum L.) To Improve Saccharification And Biomass Yields For Biofuels, Jonathan Duran Willis

Doctoral Dissertations

The natural recalcitrance of plant cell walls is a major commercial hurdle for plant biomass to be converted into a viable energy source as alternative to fossil fuels. To circumvent this hurdle manipulation of carbohydrate enzymes active in the cellulose and hemicellulose portions of the plant cell wall can be utilized to improve feedstocks. Production of cellulolytic enzymes by plants have been evaluated for reducing the cost associated with lignocellulosic biofuels. Plants have successfully served as bioreactors producing bacterial and fungal glycosyl hydrolases, which have altered plant growth to improve saccharification. A bioprospecting opportunity lies with the utilization of insect …

Economic And Environmental Optimization In The Supply Of Switchgrass In Tennessee, Jia Zhong

Masters Theses

The low efficiency of collection, storage and transportation in the switchgrass supply chain has hindered the commercialization of a switchgrass-based biofuel industry, even given its ecological and environmental advantages in carbon sequestrate, soil quality, water use, and pollution pressure. Thus, designing a switchgrass-based supply chain balancing both environmental and economic performance is important to expedite the development of the cellulosic biofuel industry to meet the national energy plan.

The objectives of this study are to 1) determine economic cost and multiple environmental outcomes in feedstock supply chains and 2) identify the relation between the economic and environmental performances. The first …

Selected Costs And Benefits Of Protecting Vital Wildlife Habitats While Producing Biofuel, Benjamin Lewis Totty

Masters Theses

The objective of this study is to estimate selected costs and benefits of meeting the 2022 biofuel production mandates using switchgrass as the feedstock. This study involves the simulation of three scenarios to evaluate the cost of protecting and promoting biodiversity while producing switchgrass for biofuel. Two models are used in this study. The first, the Biofuels Facility Location Analysis Modeling Endeavor (BioFLAME), was developed at the University of Tennessee to study biorefinery location, feed stock source areas and costs associated with biofuel production. The second model was developed by the Nature Conservancy as part of Tennessee’s State Wildlife Action …

Sp731-A Native Warm-Season Grasses For Mid-South Forage Production, Patrick Keyser, Craig Harper, Gary Bates, John Waller, Elizabeth Doxon

Animals/Livestock

No abstract provided.

Impact Of Switchgrass Bioenergy Feedstock Production On Soil Carbon Dioxide Flux And Below Ground Soil Organic Carbon Storage In East Tennessee, Leah Denise Soro

Masters Theses

Bioenergy production from switchgrass has shown promise in restoring degraded soils and helping to mitigate greenhouse gas (GHG) emissions. CO₂ loss and C-sequestration in soils are important topics for research to better understand the environmental impacts of bioenergy crops. The need for more thorough research of the carbon cycle in soils used for bioenergy production precipitated the primary interest of this study. The specific objectives of this study were 1) to measure SOC under switchgrass production in order to predict storage of carbon in soils based on previous cropping history, land management, soil physical characteristics, and time; and to …

Evaluation Of Capital Investment And Cash Flows For Alternative Switchgrass Feedstock Supply Chain Configurations, Jie Chen

Masters Theses

Biofuels have been widely recognized as a potential renewable energy source, and the United States’ government has been interested in producing ethanol from lignocellulosic biomass such as switchgrass. To evaluate whether lignocellulosic biomass based biofuels production is economically feasible, this paper estimated the capital investment outlays, operation costs, and net present value for investment in alternative switchgrass feedstock supply chain configurations in East Tennessee a 25 million gallon per year ethanol biorefinery. Two scenarios are analyzed in the study. The conventional hay harvest scenario includes the production, harvest, storage and transportation of biomass feedstocks from the fields to the biorefinery. …

Establishment And Persistence Of Legumes In Switchgrass Biomass And Forage/Biomass Production Systems, Kara Spivey Warwick

Masters Theses

Switchgrass, Panicum virgatum, is being developed as an economically and ecologically sustainable biomass crop. Nitrogen is considered one of the most limiting inputs of switchgrass. Alternatives to synthetic nitrogen fertilization may be nitrogen-fixing legumes interseeded into switchgrass. The objectives of this research were: (1) develop efficient legume management strategies for switchgrass production systems, (2) evaluate and identify cool and warm-season legumes that can be grown compatibly with switchgrass, (3) determine whether switchgrass yields are increased by legume N-fixation, and (4) determine N-fixation of common (Vicia sativa) and hairy vetch (Vicia villosa).

This study examined the …

Nitrogen Fixation And Seeding Rates Of Common Vs. Hairy Vetch For Interseeding Into Established Switchgrass Stands, K. Warwick, F. L. Allen, Patrick D. Keyser, G. E. Bates, D. D. Tyler, P. L. Lambdin, A. J. Ashworth

Research Reports

Interest in alternatives to synthetic nitrogen (N) fertilizer sources for switchgrass (Panicum virgatum L.) production, such as interseeding with N- fixing legumes continues to increase. Common vetch (Vicia sativa) is a N-fixing legume that occurs naturally throughout the U.S. and has less hard seed than hairy vetch (Vicia villosa), making it potentially less invasive, and it may fix N at similar rates to that of hairy vetch. However, little data exist to substantiate this. In this study, N-fixation rates via the N-difference method were determined to be 59.3 and 43.3 kg N ha-1 …