Master of Arts / Department of Landscape Architecture/Regional and Community Planning / Claude A. Keithley / In these times of high energy costs, dwindling supplies of fossil fuels, and talk of “global warming,” we must decide what we are going to do to with the abundance of wind energy available in Kansas. We can no longer afford to “drift,” not caring about the sources of our electricity, or what we are doing to the planet. We must act now to ensure a bright future for our children. Many wind turbines are being erected across Kansas, and this natural resource of wind energy is one that should be tapped, but only after careful planning. There are many factors to consider regarding wind farms; environmental concerns, economics, impacts on the health and well-being of individuals living near wind farms, and tax implications, to mention only a few. Studies are being completed on these issues, and due consideration must be given prior to construction. There are areas across the state that should be avoided when locating wind farms, and other areas in which wind turbines might be a natural “fit.” It is the latter areas which should be the focus of attention for construction, but again, only after giving careful consideration to the overall effects. Wind energy has become a part of Kansas, but future site selections should be done only after careful planning.

Master of Science / Department of Grain Science and Industry / Praveen V. Vadlani / In our study, five different bioenergy crops: wheat straw (Triticum aestivum), forage sorghum stover (sorghum bicolor), switchgrass (Panicum virgatum), miscanthus (Miscanthus giganteus) and sweet sorghum baggase (Sorghum bicolor) were evaluated for bio-ethanol production at 20% (w/v) initial substrate concentration under separate hydrolysis and fermentation (SHF) process. The substrates were ground to pass through 600µm mesh size and treated with 2% (w/v) NaOH at 121oC for 30 minutes. The washed and neutralized pretreated residues were subjected to saccharification using cellulase and β-glucosidase enzymes (ratio 1:1.25) at concentrations of 25 filter paper unit (fpu)/g and 31.25fpu/g, respectively, in pH 5.0 citrate buffer in an orbital incubator shaker at 150 rpm for 72 h. The hydrolysate obtained was centrifuged and supernatant was collected for fermentation. Fermentation was performed in shake flasks using Saccharomyces cerevisiae at 10% (w/v) inoculum concentration at 100 rpm for 24 h. Alkali treatment was effective in delignification of all the biomass feedstocks. The highest percent removal on raw biomass basis was attained for sorghum stover BMR-DP (81.3%, w/w) followed by miscanthus (79.9%, w/w), sorghum stover BMR-RL (69.2 %, w/w), wheat straw (68.0 %, w/w), switchgrass (66.0%, w/w), and sorghum baggase (65.4%, w/w). Glucan saccharification varied from 56.4-72.6 % (w/w) corresponding to a glucose levels of 0.45-0.34 g/g of dry substrate. Highest saccharification was observed for wheat straw while lowest was observed for miscanthus after 48 hours of hydrolysis. A maximum final ethanol concentration of 4.3% (w/v) was observed for wheat straw followed by sorghum baggase (4.2%), sorghum RL-BMR (3.6%), miscanthus (3.4%), sorghum DP-BMR (3.4%), and switchgrass (3.2%). From our studies, it is evident that high substrate concentration used for enzymatic hydrolysis was able to provide high final ethanol concentration. The lignin content and its arrangement in different biomass feedstocks may have affected saccharification and subsequent ethanol production. Bulk density and flowability are the two major key parameters that should be addressed to reduce processing cost of biomass for bioethanol production. Pelleting of biomass can increase the bulk density, thereby reducing the handling and transportation costs. In addition to above study, I analyzed the changes in chemical composition due to pelletization and pretreatment, and its effect on ethanol production by comparing unpelleted and pelleted biomass ethanol production efficiency. Wheat straw and big bluestem pelleted and unpelleted biomass were compared for their ethanol production efficiency. Pelleted and unpelleted wheat straw (Triticum aestivum) and bigblue stem (Andropogon gerardii Vitman) at a substrate concentration of 10% (w/v) were subjected to 2% NaOH treatment at 1210C for 30 min and the resulting residues were analyzed for changes in chemical composition. Saccharification of residue was done at substrate concentration of 12% (w/v) for 48 h. The sugars obtained were fermented to ethanol using Saccharomyces cerevisiae. Pelletization did not significantly affect the chemical composition of biomass in terms of glucan, xylan and lignin content. Delignification of pelleted biomass was greater than unpelleted biomass. Pelletization did not influence final ethanol production for both substrates.

Master of Science / Department of Mechanical and Nuclear Engineering / Guoqiang Hu / Warren N. White / In recent years, the concern has risen to establish clean sources for electric power generation. In 2009, Kansas established an RPS (Renewable Portfolio Standard) mandating utilities acquire 20% of their electricity from renewable energy by 2020 [32]. One of the most prominent renewable energy sources is wind energy. Utility companies now are investing more in wind capture systems to comply with this mandate. This increase in the manufacture of wind turbines has caused researchers to investigate methods to improve the efficiency of captured wind energy and where improvements can be made. This thesis takes a control theory approach to maximizing the power capture of a wind turbine using the concepts of robust estimation, nonlinear control, and Lyapunov-based maximization. A two step control approach to optimize the power capture of a wind turbine is proposed. First, a robust controller is used to estimate unknown aerodynamic properties and regulate the wind turbine tip-speed ratio as it tracks a desired trajectory. Once the tip-speed ratio is regulated within a given tolerance, a Lyapunov-based control approach is developed to provide the robust controller with a desired trajectory to track. This is done by estimating the unknown coefficient of performance of the wind turbine. A discrete update law is then developed to alter the tip-speed ratio and the blade pitch of the wind turbine so that the coefficient of performance is maximized. A simulation is provided of this control strategy and tested under time varying wind conditions and measurement noise in order to demonstrate the controller’s performance. The system simulated is intended to emulate a commercial wind turbine operating in a realistic environment. A detailed discussion of the simulation model, control scheme, and results will be provided to supplement the theoretical controller development, as well as future work for this control application.

Master of Agribusiness / Department of Agricultural Economics / Allen M. Featherstone / The cost of energy is a major concern for the United States and its citizens. With domestic demand at all time highs, the need for renewable fuels has become a key in reducing our countries reliance on imported energy. It is important for the U.S. to examine the feasibility of producing its own energy from renewable resources that can be grown domestically. Along with the potential financial gains from renewable fuels, the ability to control the supply of energy for the U.S. is also very important. With the amount of oil imported by the U.S., the ability to produce more of our nations needs and not be forced to rely on other countries could be important for our country moving forward. With the political unrest in many oil producing areas, the security of energy independence is a goal for the U.S. This study uses United States Department of Agriculture, Pro Exporter, Advance Trading, and other statistical sources to analyze the economic feasibility of an ethanol plant near Des Moines, IA. It looks at the available supply of corn in the area as well as the production of ethanol and distillers grains. An increase in the price of imported oil does not necessarily results in an economically viable ethanol plant. Many variables go into the economic viability of an ethanol plant and consumers will still buy the low cost good, and that may be imported energy. Some of these variables affecting economic viability include corn price and availability, denaturant price, natural gas price, ethanol demand and distillers grains demand. With the push for cleaner air and a cleaner environment, ethanol is also used as a gasoline additive to reduce emissions. As more states regulate a higher inclusion rate of ethanol, this will continue to create greater demand. A 100 million gallon ethanol plant is an economically viable investment in the Des Moines area, but when looking at the sensitivity tests, the better investment option if investors want to enter the ethanol industry, is to buy an existing ethanol plant.

Master of Agribusiness / Department of Agricultural Economics / Allen M. Featherstone / During the past 10 years, ethanol production in the United States has grown exponentially. From 2000 to 2009 U.S. ethanol production increased from 1.6 billion gallons annually to 10.8 billion gallons annually. In 2010, U.S ethanol production increased by 23 percent from 2009 to 13.23 billion gallons. The increase in ethanol production was due to lawmakers reacting to skyrocketing oil prices by implementing a Renewable Fuels Standard (RFS) in 2005 and expanding the RFS in 2007. The RFS requires the use of specified amounts of biofuels, such as ethanol, through the year 2022. The creation of the RFS represented a step beyond lawmakers’ usual policy of using the tax code to promote ethanol production. There is a long history of encouraging ethanol production by using the tax code, but the implementation of a biofuels mandate is new and therefore there is not a great deal of research on the effects of such a policy. This study analyzes U.S. oil, unleaded gasoline, corn and ethanol prices dating back to 1985 to determine the impact that the RFS has had on corn prices. The key question answered is whether the creation and expansion of the RFS has brought the instability of the oil market into the corn market. The prices that an ethanol plant in western Kansas paid for the grain it used to produce ethanol and the price that the plant received for the ethanol that it produced are also analyzed. The plant began operation in January 2004, so it is possible to analyze the grain and ethanol prices both before and after the implementation and expansion of the RFS. To study the impact of the RFS creation and expansion, the prices were analyzed to see if there was an increase in the correlation after the creation and expansion of the RFS. Regression analysis of the national corn prices and the prices that Western Plains Energy paid for the grain that it used to produce ethanol; and regression analysis of the national price of ethanol and the price that Western Plains Energy sold its ethanol for were also used to study the impact of the RFS. Finally, the vector autoregression (VAR) model is used to analyze the dynamic relationships between the variables in the system: corn price, oil price, ethanol price and unleaded gasoline price. The analysis of the correlation reveals that both at the national and plant level grain and oil prices track much more closely together after the creation and then expansion of the RFS. The VAR reveals that there is some relationship between corn and oil prices contemporaneously. The correlation matrix of residuals reveals that there is not a strong correlation between national corn and oil prices. The results suggest the need for greater research in this area. The creation and expansion of the RFS represented a step into uncharted territory and the consequences are still not known.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Donghai Wang / Scott R. Bean / Sorghum has been considered one of the best species dedicated to biofuel production because of its drought tolerance, low fertilizer or pesticide input, established production systems, and genetic diversity. The mission of this research was to better understand the relationship among "genetic-structure-function-conversion." The main focus of this research was to study the impact of sorghum proteins on ethanol fermentation and to investigate novel methods for evaluation of sorghum fermentation quality. Changes of sorghum protein in digestibility, solubility, and microstructure during mashing were characterized. Sorghum proteins tended to form highly extended, strong web-like microstructures during mashing. The degree of protein cross-linking differed among samples. Formation of web-like microstructures due to cross-linking reduced conversion efficiency. A rapid method for extracting proteins from mashed and nonmashed sorghum meal using sonication (ultrasound) was developed, with which the relationships between the levels of extractable proteins and ethanol fermentation properties were determined. There was a strong relationship between extractable proteins and fermentation parameters. Ethanol yield increased and conversion efficiency improved significantly as the amount of extractable proteins increased. The Rapid-Visco Analyzer (RVA) was used to characterize pasting properties of sorghum grains. Results showed a strong linear relationship between ethanol yield and final viscosity, as well as setback. A modified RVA procedure (10 min) with an application of α-amylase was developed to simulate the liquefaction step in dry-grind ethanol production. There was a remarkable difference in mashing properties among the sorghum samples with the normal dosage of α-amylase. The modified RVA procedure is applicable not only for characterization of mashing properties but also for prediction of tannin content and for optimization of [alpha]-amylase doses for starch liquefaction. A small-scale mashing (SSM) procedure requiring only 300 mg of samples was investigated as a possible method of predicting ethanol yield of sorghum grain. There was a strong linear correlation between completely hydrolyzed starch (CHS) from SSM and ethanol yields from both traditional and simultaneous saccharification and fermentation procedures. CHS was a better indicator for predicting ethanol yield in fermentation than total starch.

Master of Science / Department of Architecture / R. Todd Gabbard / This research aims to explore and assess passive solar design techniques that promote high thermal comfort in vernacular houses of the state of Jharkhand in India. The study of these houses provides useful insights for designing energy efficient houses that provide thermally comfortable conditions. An analysis of these houses in Ranchi, the capital city of Jharkhand, India provides a context for the field research. Jharkhand predominantly has two different styles of vernacular houses: huts and havelis. These houses were constructed, without any mechanical means, in such a manner as to create micro-climates inside them to provide high thermal comfort levels. Hence the study of thermal comfort levels in these buildings in relation to built environment in today's context is significant. As part of data collection, interviews were conducted with the occupants of ten houses in Ranchi, in June 2007. Two houses of each (huts and havelis) were selected for detailed experimental analysis. Experiment results indicated that all the four selected houses exhibited lower ambient temperature than outside during the day and a higher ambient temperature at night. Brick bat coba and lime mortar were the key materials used for constructing high thermal-mass walls. Adequate ventilation is significant in creating conditions that are comfortable. Aperture to volume ratio of less than 0.051 is not adequate enough to cool the thermal mass of these houses. These houses also use attic space to mitigate the heat gain from the roof. Courtyards and other exterior spaces form an integral part of these houses and influence the thermal conditions in and around the houses. The case studies show that there is a scope for more relaxation of comfort temperature range based on culture and phenomenon of acclimatization. A universal approach in understanding and defining comfort condition fails because the users of these houses were comfortable in conditions defined as uncomfortable by ASHRAE and Nicol.

Master of Agribusiness / Department of Agricultural Economics / Jeffery R. Williams / The objective of this thesis is to conduct a net present value analysis of installing a solar power generation system on company owned turkey grow out ranches. This research project provides information regarding the systems power production capacity, investment cost, maintenance requirements, amount of energy saved, useful life of the equipment, marginal state and federal tax brackets for the company. The investment cost of the system includes the price of the equipment and installation service. Many of the system costs may be offset by rebates, tax credits and grants from various government agencies. These must also be included in the financial analysis as they can greatly affect the financial viability of the project. The system is projected to have a useful life of 30 years with an inverter replacement planned for year 15. Four scenarios were evaluated using two levels of rebates and two electrical rate inflation levels. The evaluations conducted showed positive after tax NPV evaluations on three of four scenarios reviewed with the most financially attractive options available when the rebates, tax credits and grants were maximized. This was the case at both electrical rate inflation scenarios. These same scenarios produced favorable results when looking at reduction of live production ranch costs. The system effectively locked in electrical rates below current rates for the 30 year life of the system. This reduced ranch live production cost by as much as 11.73 percent. It also gives the company an advantage over the competition when used as a marketing tool due to the use of green technology in company production practices.

Master of Science / Department of Biological and Agricultural Engineering / Donghai Wang / Acid catalysts have been successfully used for pretreatment of cellulosic biomass to improve sugar recovery and its later conversion to ethanol. However, use of acid requires a considerable equipment investment as well as disposal of residues. Acid-functionalized nanoparticles were synthesized for pretreatment and hydrolysis of lignocellulosic biomass to increase conversion efficiency at mild conditions. Advantages of using acid-functionalized metal nanoparticles are not only the acidic properties to catalyze hydrolysis and being small enough to penetrate into the lignocellulosic structure, but also being easily separable from hydrolysis residues by using a strong magnetic field. Cobalt spinel ferrite magnetic nanoparticles were synthesized using a microemulsion method and then covered with a layer of silica to protect them from oxidation. The silanol groups of the silica serve as the support of the sulfonic acid groups that were later attached to the surface of the nanoparticles. TEM images and FTIR methods were used to characterize the properties of acid-functionalized nanoparticles in terms of nanoparticle size, presence of sulfonic acid functional groups, and pH as an indicator of acid sites present. Citric acid-functionalized magnetite nanoparticles were also synthesized and evaluated. Wheat straw and wood fiber samples were treated with the acid supported nanoparticles at 80°C for 24 h to hydrolyze their hemicellulose fraction to sugars. Further hydrolysis of the liquid fraction was carried out to account for the amount of total solubilized sugars. HPLC was used to determine the total amount of sugars obtained in the aqueous solution. The perfluroalkyl-sulfonic acid functional groups from the magnetic nanoparticles yielded significantly higher amounts of oligosaccharides from wood and wheat straw samples than the alkyl-sulfonic acid functional groups did. More stable fluorosulfonic acid functionalized nanoparticles can potentially work as an effective heterogeneous catalyst for pretreatment of lignocellulosic materials.

Doctor of Philosophy / Department of Electrical and Computer Engineering / Anil Pahwa / Shelli K. Starrett / Analysis of power system voltage stability has practical value in increasing wind penetration levels. As wind penetration levels increase in power systems, voltage stability challenges arise due to locating wind resources far away from load centers. This dissertation presents several different voltage stability methods for sizing new wind farms. Power system wind penetration levels depend on the available voltage stability margins (VSMs) of the existing power system and system load characteristics. Three new iterative methods have been developed to maximize wind penetration level in weak power systems based on systems’ VSMs. The first two methods use an iterative approach for increasing the size of each wind farm until reaching the collapse point. Wind farms with less negative impact on system VSMs are sized larger than others. A third wind farm sizing method has been developed using modal analysis in conjunction with the traditional voltage stability method (Q-V method). Wind farms are placed at buses in the power system which have the lowest negative impact on voltage instability modes (strong wind injection buses). By placing the wind farms at the strongest wind injection buses, higher amounts of wind power can be injected into the power system. To further increase wind penetration in weak power systems, two additional techniques are introduced and applied to the western Kansas power system. The first technique uses modes of voltage instability to place voltage support equipment like static var compensators at locations in the power system where they provide the needed reactive power support for increasing levels of wind penetration. The second technique uses the fact that wind patterns at a wind farm site may rarely allow the wind farm to produce its maximum capacity during the peak loading hours. Wind farm maximum sizes can be increased above their maximum voltage stable size limit without driving the power system into becoming voltage unstable. Preventing voltage collapse for the additional increases in wind farm sizes is accomplished by disconnecting some wind turbines inside the wind farm during critical times to reduce its power output to a voltage stable level.