Doctor of Philosophy / Department of Agronomy / Scott Alan Staggenborg / Ethanol from cellulose and biodiesel are both advanced biofuels according to the renewable fuel standard version two (RFS2) as part of the Energy Independence and Security Act of 2007. Agricultural production of feedstocks for these fuels can occur as co-products from the primary use of the crops. Use of cellulosic material produced from annual grain and sugar crops does not displace land use from grain and sugar production. Production of corn (Zea mays L.), grain sorghum, dual purpose forage sorghum, sweet sorghum, and photoperiod sensitive sorghum (Sorghum bicolor (L.) Moench) are all primarily driven for products other than cellulosic ethanol. Corn production if driven by grain and silage markets with fodder occasionally used for forage. Grain sorghum production is driven by grain markets and grown primarily in semi arid regions. Dual purpose forage sorghum is used for forage both as baled hay and as silage. Sweet sorghum is produced for sugar and molasses production. Photoperiod sensitive sorghum is produced for baled hay. The current study tests the effect of seeding rate on cellulosic ethanol on each crop. Yellow grease is the most common source of oil for biodiesel production. Intensification of oil crop production may increase the feedstock availability for biodiesel. The current study uses double cropping of spring camelina (Camelina sativa (L.) Crantz), spring canola (Brassica napus L.), sesame (Sesamum indicum L.), safflower (Carthamus tinctorius Mohler, Roth, Schmidt and Bourdeux), soybean (Glycine max L.), and sunflower (Helianthus annuus L.) to search for cropping system options that will produce more oil on an annual basis than full season crops. The full season crop options used were maturity group IV soybean, maturity group V soybean, and full season sunflower. Fertility inputs are inherently less for the non legume crops due to the N fixation ability of symbiotic rhizobium. Canola and camelina are also more sensitive to sulfur deficiency than many crops. Long chain and polyunsaturated fatty acids have higher market values than biodiesel. Separation of these fatty acids from the lipid profile of oil seed crops provides additional demand for oil seed crops. Demand for the crops will drive commodity prices and move land use into oil crop production. The second year of oilseed production provided an opportunity to look at lipid profiles of successfully produced crops during a drought year. Three new discoveries were concluded. Grams cellulosic ethanol g[superscript]-1 stover is not affected by density within the densities considered. Among the double crop options tested only sesame after spring crops was viable in normal years and none were viable in an extreme drought year. Lipid profiles are provided for crops produced in concurrent field growing conditions.

Doctor of Philosophy / Department of Grain Science and Industry / Sajid Alavi / The Renewable Fuel Standard (RFS) in the Energy Independence and Security Act of 2007 has set the goal of 36 billion gallons of annual ethanol production in the U.S. by 2022, which is equivalent to 17.5% of the current gasoline consumption in the U.S. However, corn ethanol is expected to plateau at a level of 7.3% of current gasoline consumption on an energy-equivalent basis. Thus, it is essential to utilize a variety of substrates including lignocellulosic biomass from perennial energy crops such as switch grass, crop residues such as corn and sorghum stover, and agri-industrial co-products such as soybean hulls and wheat bran. Lignocellulosic substrates have a recalcitrant nature and require a pretreatment step that is critical for efficient enzymatic hydrolysis of cellulose and hemicellulose to fermentable sugars. In this study, soybean hulls were used as a model substrate for cellulosic ethanol. A novel thermo-mechanical pretreatment process using extrusion was investigated and compared with two traditional pretreatment methods, dilute acid and alkali hydrolysis, with regard to structural changes in the lignocellulosic substrate, and glucose and ethanol yields. The effect of extrusion parameters, such as barrel temperature, in-barrel moisture and screw speed, on glucose yield from soybean hulls was determined. Optimum processing conditions were screw speed of 350 rpm, maximum barrel temperature of 80C and 40% in-barrel moisture content, resulting in 95% cellulose conversion to glucose. Compared with untreated soybean hulls, the cellulose to glucose conversion of soybean hulls increased by 69.5, 128.4 and 132.2% for dilute acid, alkali and thermo-mechanical pretreatments, respectively. Glucose and other hexose sugars such as mannose and galactose were effectively fermented by Saccharomyces cerevisiae, resulting in ethanol yields of 13.04–15.44 g/L. Fermentation inhibitors glycerol, furfural, 5-(hydroxymethyl)-2-furaldehyde (HMF) and acetic acid were found in the thermo-mechanically pretreated substrate, ranging in concentrations from 0.072–0.431, 0–0.049, 0–0.023 and 0.181–0.278 g/L, respectively, which were lower than those reported from acid hydrolyzed substrates. The economic feasibility of commercial cellulosic ethanol production processes employing dilute acid hydrolysis and thermo-mechanical pretreatment were compared using a system dynamics modeling approach. It was concluded that low feedstock cost and high sugar conversion are important factors that can make cellulosic ethanol production commercially viable. Thermo-mechanical pretreatment was a more promising technology as compared to dilute acid hydrolysis because of the lower capital and operating costs, and higher sugar conversion.

Doctor of Philosophy / Department of Chemistry / Stefan H. Bossmann / Porin A from Mycobacterial smegmatis (MspA) is an octameric trans-membrane channel protein and is one of the most stable porins known to date. MspA has been successfully isolated and purified to obtain liquid extracts and crystals using a modified extraction procedure. A full analytical assessment has been carried out to authenticate its’ structure, including gel electrophoresis, spectroscopy (fluorescence, UV, FTIR, NMR), HPLC, Bradford protein assay, dynamic light scattering and X-ray crystallography. Nanoscopic vesicle formation of MspA molecules in aqueous media has been thoughroughly investigated. Temperature dependent dynamic light scattering experiments reveal that size of such vesicles is dependent on temperature but is independent of ionic strength of the medium. Zeta potential measurements reveal a steady build up of positive charge on the vesicle surface with increasing temperature. For the first time, wild type (WT) MspA has been utilized as a channel forming agent. This phenomenon has future potential in DNA sequencing and the development of antimycobacterial drugs. Channel activity of WT MspA and mutant A96C MspA has been investigated and has shown to form stable channels across DPhPC lipid bilayers. Blocking of the channel current via external molecules (i.e. channel blocking) is an extremely important process, which helps to evaluate the biosensor ability of the pore. In this regard, two Ruthenium based compounds, Ru(QP-C2)38+ (i.e. RuC2) and Ru(bpy)32+have been successfully employed as channel blocking agents. Both compounds show evidence for channel blocking of WT MspA. However, these results are not reproducible. Three dimensional aggregation behavior of RuC2-MspA vesicles have been thoughroughly investigated. It is evident that addition of RuC2 significantly increases vesicle size and polydispersity of MspA aggregates in solution. The results provide explanations onto the lack of channel blocking ability of MspA by RuC2. Development of a ‘greener’ dye sensitized solar cell with the use of MspA as an electron carrier is investigated for the first time. A series of Ru(II)-phenanthroline-based dyes have been synthesized as non-toxic dyes in this regard. Chemical binding between the dyes and MspA has been achieved successfully. Two types of solar cell prototypes, i.e. TiO2-based (Grätzel type) and FTO-based have been developed and tested. Significant current generation and conversion efficiencies have been achieved for both cell types. This marks the first development of a protein-based photovoltaic device, which has the potential to be developed as a new class of “hybrid soft solar cells”.

Master of Science / Department of Biological and Agricultural Engineering / Donghai Wang / Biomass torrefaction is an important preprocessing step in improving biomass quality, specifically in terms of physical properties and chemical composition. The objective of this research was to study effects of torrefaction as a pretreatment method on chemical and elemental compositions and thermal properties of Conservation Reserve Program (CRP) biomass. Most CRP grasslands are a mixture of native grasses, and in the state of Kansas, species including indiangrass, big bluestem, little bluestem, sideoats grama, and switchgrass comprise a majority of CRP grounds. Pure forms of big bluestem biomass were analyzed and compared with a mixture of the species that make up CRP lands. Two strategies for torrefaction were tested: one with a pre-dry step and one without. After torrefaction, big bluestem and CRP biomass showed an increase in energy density, making the biomass more attractive as a biofuel source than raw biomass. Big bluestem also showed slightly higher calorific values than that of CRP biomass. The torrefaction process had a significant effect on chemical composition and elemental composition of the biomass. Carbon content increased and oxygen content decreased as torrefaction temperature increased. Glucan and xylose decreased and lignin increased as torrefaction temperature increased. Pre-drying biomass before torrefaction is beneficial to torrefaction of biomass with high moisture content because moisture removal leads to less dry matter loss while maintaining the same calorific value.

Master of Science / Department of Agricultural Economics / Jeffery Williams / Ethanol has become an important source of energy for transportation purposes in the U.S. The majority of the feedstock for this ethanol is corn grain. The use of crop residues and perennial grasses has been proposed as an alternative feedstock for ethanol production using cellulosic conversion processes. Commercial scale production of cellulosic ethanol is still on the horizon. In the meantime a wide variety of studies examining both the technical and economic feasibility of cellulosic ethanol production have been conducted. This is the first study that combines both county level cellulosic feedstock production and farmer participation rates to determine the feasibility of supplying it to cellulosic ethanol plants. This research determines the economic feasibility of supplying cellulosic feedstocks to seven potential add-on cellulosic ethanol plants of 25 million gallons per year at seven existing starch ethanol plants in Kansas. The feedstocks considered are corn stover, sorghum stalks, wheat straw, and perennial switchgrass. A mixed integer programing model determines the amount and mix of cellulosic feedstocks that can be delivered to these plants over a range of plant-gate feedstock prices given transportation costs and farm-gate production costs or breakeven prices. The variable costs of shipping are subtracted from the difference between plant-gate price and farm-gate price to find savings to the plant. The objective function of the model minimizes transportation costs which in turn maximizes savings to the plant. The role switchgrass may have as a feedstock given various switchgrass production subsidies is examined. The results indicate the minimum plant-gate price that must be paid to feedstock producers for all plants to have enough cellulosic feedstocks is $75 per dry ton. Switchgrass feedstocks were only a minor portion of biomass supplied and used without a production subsidy. A Biomass Crop Assistance Program payment increased the supply of switchgrass more than other production subsidies.

Master of Science / Department of Biological and Agricultural Engineering / Wenqiao Yuan / Gasification is an efficient way to produce energy from biomass, which has significant positive impacts on the environment, domestic economy, national energy security, and the society in general. In this study, a lab-scale updraft biomass gasifier was designed, built, and instrumented for stable gasification using low-bulk density biomass. Related accessories, such as a biomass feeder, inlet air temperature controller, air injection nozzle, and tar cracking system, were also developed to enhance gasifier performance. The effect of operation parameters on gasifier performance was studied. Two operational parameters, including air flow rate and feed-air temperature, were studied on three sources of biomass: prairie hay, sorghum biomass, and wood chips. Results showed that higher air flow rate increased tar contents in syngas for all three types. It was also found that different biomasses gave significantly different tar contents, in the order of wood chips>sorghum biomass>prairie hay. Feed-air temperature did not have a significant effect on tar content in syngas except for prairie hay, where higher feed air temperature reduced tar. A statistical model was implemented to study differences on syngas composition. Results showed that different biomasses produced syngas with different high heating value, e.g., wood chips > prairie hay > sorghum biomass. CO composition also showed differences by feed air temperature and biomass, e.g. prairie hay>wood chips>sorghum biomass, but H[subscript]2 did not show significant differences by either biomass type or operating conditions. Moreover, because of the downstream problems caused by tars in syngas such as tar condensation in pipelines, blockage and machinery collapse, an in-situ tar cracking system was developed to remove tars in syngas. The tar cracking device was built in the middle of the gasifier’s combustion using gasification heat to drive the reactions. The in-situ system was found to be very effective in tar removal and syngas enhancement. The highest tar removal of 95% was achieved at 0.3s residence time and 10% nickel loading. This condition also gave the highest syngas HHV increment of 36% (7.33 MJ/m[superscript]3). The effect of gas residence time and Ni loading on tar removal and syngas composition was also studied. Gas residence of 0.2-0.3s and Ni loading of 10% were found appropriate in this study.

Doctor of Philosophy / Grain Science and Industry / Praveen V. Vadlani / Lignocellulosic biomass feedstocks are a sustainable resource required for rapid growth of bio-based industries. An integrated approach, including plant breeding, harvesting, handling, and conversion to fuels, chemicals and power, is required for the commercial viability of the lignocellulosic-based biorefineries. Optimization of conversion processes, including biomass pretreatment and hydrolysis, is a challenging task because of the distinct variations in composition and structure of biopolymers among biomass types. Efficient fermentation of biomass hydrolyzates comprising of different types of sugars is challenging. The purpose of this doctoral research was to evaluate and optimize the various processing steps in the entire the biomass value chain for efficient production of advanced biofuels and chemicals from diverse biomass feedstocks. Our results showed that densification of bulky biomass by pelleting to better streamline the handling and logistic issues improved pretreatment and hydrolysis efficiencies. Alkali pretreatment was significantly more effective than acid pretreatment at same processing conditions for grass and hardwood. The ethanol-isopropanol mixture, and glycerol with 0.4% (w/v) sodium hydroxide were the promising organic solvent systems for the pretreatment of corn stover (grass), and poplar (hardwood), respectively. None of the pretreatment methods used in this study worked well for Douglas fir (softwood), which indicates a need to further optimize appropriate processing conditions, better solvent and catalyst for effective pretreatment of this biomass. The brown midrib (bmr) mutations improved the biomass quality as a feedstock for biochemicals production in some sorghum cultivars and bmr types, while adverse effects were observed in others. These results indicated that each potential sorghum cultivar should be separately evaluated for each type of bmr mutation to develop the best sorghum line as an energy crop. Development of an appropriate biomass processing technology to generate separate cellulose and hemicellulose hydrolyzates is required for efficient 2,3-butanediol (BD) fermentation using a non-pathogenic bacterial strain, Bacillus licheniformis DSM 8785. This culture is significantly more efficient for BD fermentation in single sugar media than Klebsiella oxytoca ATCC 8724. Though K. oxytoca is a better culture reported so far for BD fermentation from diverse sugars media, but it is a biosafety level 2 organism, which limits its commercial potential.

Doctor of Philosophy / Agronomy / Charles W. Rice / Substitution of cellulosic biofuel in place of gasoline or diesel could reduce greenhouse gas (GHG) emissions from transportation. However, emissions of nitrous oxide (N₂O) and changes in soil organic carbon (SOC) could have a large impact on the GHG balance of cellulosic biofuel, thus there is a need to quantify these responses in cellulosic biofuel crops. The objectives of this study were to: (i) measure changes in yield, SOC and microbial communities in potential cellulosic biofuel cropping systems (ii) measure and characterize the temporal variation in N₂O emissions from these systems (iii) characterize the yield and N₂O response of switchgrass to N fertilizer and to estimate the costs of production. Sweet sorghum, photoperiod-sensitive sorghum, and miscanthus yielded the highest aboveground biomass (20-32 Mg ha⁻¹). The perennial grasses sequestered SOC over 4 yrs, while SOC stocks did not change in the annual crops. Root stocks were 4-8 times higher in the perennial crops, suggesting greater belowground C inputs. Arbuscular mycorrhizal fungi (AMF) abundance and aggregate mean weight diameter were higher in the perennials. No consistent significant differences were found in N₂O emissions between crops, though miscanthus tended to have the lowest emissions. Most N₂O was emitted during large events of short duration (1-3 days) that occurred after high rainfall events with high soil NO₃₋. There was a weak relationship between IPCC Tier 1 N₂O estimates and measured emissions, and the IPCC method tended to underestimate emissions. The response of N₂O to N rate was nonlinear in 2 of 3 years. Fertilizer induced emission factor (EF) increased from 0.7% at 50 kg N ha⁻¹ to 2.6% at 150 kg N ha⁻¹. Switchgrass yields increased with N inputs up to 100-150 kg N ha⁻¹, but the critical N level for maximum yields decreased each year, suggesting N was being applied in excess at higher N rates. Yield-scaled costs of production were minimized at 100 kg N ha-1 ($70.91 Mg⁻¹). Together, these results show that crop selection and fertilizer management can have large impacts on the productivity and soil GHG emissions biofuel cropping systems.

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Mary C. Kingery-Page / Rural Kansas communities are almost entirely dependent on large energy corporations. These corporations, in turn, are almost completely dependent on fossil fuels for energy production. Three major implications exist within these dependencies: 1) the dependence of rural communities on large corporations reduces the potential of a local economy to support itself; 2) the dependence on fossil fuels has severe environmental impacts; and 3) fossil fuels are non-renewable resources and will inevitably be exhausted. A rural Kansas community has resources necessary to achieve and maintain energy independence in a renewable manner. The design of these systems in regard to economy, society, aesthetics, technology, and ecology will play a key role in sustaining these resources into the future. The intent of the project is to create a tool for rural communities to evaluate localized renewable energy potential using Washington, Kansas as an example. Several questions were addressed to determine the capacity and feasibility of each local energy resource: What renewable energy resources are available to a rural Kansas community and are they sufficient for the community to achieve energy independence? How can the resource or its production be designed and maintained in regard to its environmental impact and long-term viability? What are the implications of energy independence for the community’s identity? Because each question is dependent upon the answer to a previous question, a decision tree was the most viable method for the project’s analysis and development. Research into the technology and science associated with each resource provided a general knowledge of the definitions associated with and processes necessary to determine the feasibility of the resource. For resources receiving a positive feasibility rating, analysis continued with a basic cost/benefit analysis that compares potential costs involving implementation and maintenance with the payback, offsets, and incentives involved in utilizing each resource. Analysis of each feasible resource continued with site suitability analysis. The analysis of each resource resulted in resource maps showing potential implementation locations for three renewable resources studied: hydro, wind, and solar. The maps and accompanying graphics communicate the integration of renewable energy technologies into the existing community’s identity.

Master of Arts / Department of Economics / Tracy M. Turner / This report provides a summary of the state of wind energy in the United States, the policy instruments used to encourage renewable energy and the research finding on the benefits of wind energy. It provides insight from a Texas case study, as well as international perspectives. Renewable and non-renewable energy sources are defined and compared. The report discusses the negative environmental impacts of conventional power generation, in contrast to lack of emissions from renewable power. Background information on U.S. energy consumption and climate change are provided. The primary policies used to promote renewable energy, which apply to wind power, are explained. The economic theory behind the relationship of subsidies and externalities is explained, as well as the implications that firm profit-maximization has on market outcomes. This report finds that the benefits derived from wind energy production and the promoting policies outweigh the costs associated with them.