Many aspects associated with conversion of lignocellulose to biofuels and other valuable products have been investigated to develop the most effective processes for biorefineries. The goal of this research was to improve the efficiency and effectiveness of the lignocellulose conversion process by achieving a more basic understanding of pretreatment and enzymatic hydrolysis at high solids, including kinetic modeling and separation and recovery of glucose. Effects of NaOH pretreatment conditions on saccharide yields from enzymatic hydrolysis were characterized in low- and high-solids systems. Factors associated with pretreatment and hydrolysis were investigated, including duration of pretreatment at different temperatures and NaOH loadings, as well as different solids and enzyme loadings. Under relatively mild pretreatment conditions, corn stover composition was essentially equivalent for all time and temperature combinations; however, components were likely affected by pretreatment, as differences in subsequent cellulose conversions were observed. Flushing the hydrolyzate and reusing the substrate was also studied as a method for inhibitor mitigation while increasing overall glucose yields. Flushing the PCS throughout the hydrolysis reaction eliminated the need to wash the pretreated biomass prior to enzymatic hydrolysis when supplementing with low doses of enzyme, thus reducing the amount of process water required. The robustness of an established kinetic model was examined for heterogeneous hydrolysis reactions in high-solids systems. Michaelis-Menten kinetics is the traditional approach to modeling enzymatic hydrolysis; however, high-solids reactions violate the main underlying assumption of the equation: that the reaction is homogeneous in nature. The ability to accurately predict product yields from enzymatic hydrolysis in high-solids systems will aid in optimizing the conversion process. Molecularly-imprinted materials were studied for use in both bulk adsorption and in column chromatography separations. Glucose-imprinted materials selectively adsorbed glucose compared xylose by nearly 4:1. Non-imprinted materials were neither selective in the type of sugar adsorbed, nor were they capable of adsorbing sugar at as high a capacity as the glucose-imprinted materials. Liquid chromatography with imprinted materials was not a suitable means for separating glucose from solution under the conditions investigated; however, many factors impact the effectiveness of such a separation process and warrant further investigation.

Coal-fired electricity production is the major emitter of CO2 and other greenhouse gases including NOx and SOx. Microalgae-based CO2 mitigation systems have been proposed to reduce the net CO2 emission from coal-fired power plants. This study focused on developing an optimum culture media and exploring the possibilities for recycling nutrients, which were added as commercial mineralized chemicals at the beginning of cultivation. In order to release the nutrients embedded in the cells so that they can be used as a nutrient source for new cells, Scenedesmus biomass was digested by anaerobic bacteria. Results showed that thermal pretreatment enhanced the methane production rate for the first 7 days of digestion. Three operational factors were tested: heating temperature, heating duration and NaOH dosage. The combination of 10 min heating with 3~6% NaOH at 50 °C gave the highest cell wall destruction for all samples except oven-dried algae. The anaerobic digestate, rich in mineralized nutrients including ammonium and phosphate, potassium and magnesium ions, was tested as a possible nutrient source for the algae cultivation. To cope with the high solid content of the digestates, the dosage of the digestates was reduced or the solid particles were removed prior to addition to the microalgae. Both approaches worked well in terms of providing nutrients with minimal effect on light penetration. Using digestates without any sterilization did not cause contamination or other deleterious effects on the Scenedesmus growth rate. Harvesting microalgae cells was critical to ensure a continuous and robust growth rate. The used media could be recycled at least four times without altering the algae growth. Nutrient replenishment was the key for a healthy culture when used media was incorporated. The combination of used media and digestates can sustain a normal algae growth. Life cycle assessment was conducted on the system including the photobioreactor, the anaerobic digester, the biomass settling and dewatering and used media and nutrient recycling. Considering methane as the energy source, the overall energy return of the system was 2.4. CO2 mitigation rate was about 39% under current mitigation system.

The Fan Assessment Numeration System (FANS) is an improved air velocity traverse method for measuring in situ fan performance. The FANS has been widely used, but variations of its test procedure are commonly employed to accommodate physical or operational barriers encountered in the field. This laboratory study evaluated the use of transitions to connect a 1.37m FANS unit to two smaller fans (1.22m and 0.91m diameter) and one 1.37m diameter fan. Tests were conducted with the FANS unit positioned on both intake and discharge sides of the fans. Three different transition angles (30o, 45o and 60o) and the use of no transition were evaluated. Discharge tests were also performed with no enclosed connection between FANS and fan housings. A different experiment was conducted for each fan size. Data was analyzed by comparing test results to the control with Dunnett’s procedure. Results showed significant differences as much as 5.3% ± 1.20% for intake treatments, 17.2% ± 3.04% for sealed discharge treatments and 37.1% ± 12.24% for discharge treatments with no enclosed connection. All transition angles produced similar fan test results. Differences between test results from the discharge and control treatments increased as differences between FANS and fan dimensions increased.

The surface mining method of mountaintop removal has been shown to adversely affect the water quality and hydrologic characteristics of downstream regions. Based on recent scientific literature, the U.S. EPA issued guidance on the specific conductivity (EC25ºC) of waters discharged from mined lands in the Appalachian Coal Belt Region stating that these waters should have an EC25ºC less than 300-500 μS cm-1. Hence, accurately measuring EC25ºC levels of mine discharged waters has significant implications. Furthermore, the development of reclamation techniques that positively impact the hydrological and water quality aspects of valley fill (VF) discharge is needed. To tackle these questions, a two-part study was conducted. First, a detailed study comparing sensor performance under controlled and field conditions was performed. Second, the hydrologic parameters (storm flow only) of a stream restoration project constructed atop a retrofitted valley fill were compared to a headwater stream with no mining as well as one influenced by mining with no restoration. Results indicated that significant differences were noted between four conductivity sensors with errors positively correlated with increases in EC25ºC. For storm events, the restored stream section atop the VF is performing similar to the unminded, forested watershed for some hydrologic parameters.

The microbiological testing of foods is a well-established science. Due to the severity of foodborne pathogen illnesses, the widespread use and implementation of rapid detection methods in food testing labs is increasingly important. The first step for successful testing is sampling. Surfactants have been highly used in food microbiology, but there is not much, if any, published research about the use of fatty alcohols and chemical dispersants as aids in microbial separation. The microbial extraction efficiency of Escherichia coli K12 and Listeria innocua from hot dogs, spinach, and milk was measured using chemical additives (surfactants, fatty alcohols, and a chemical dispersant) in a buffer solution. Dry matter content was calculated using the oven method to determine how clean the sample was at the end of processing. Tween 80 at 0.01% was found to be the most effective additive for microbial recovery for each food matrix examined. The addition of fatty alcohols to surfactants also showed much promise in aiding separation as well as in minimizing dry matter in the final solution. However, the use of Buffered Peptone Water as the diluting agent resulted in very high recovery percentages without the need for additives.

Sound pressure level (SPL) is known to cause stress in cattle but is often overlooked as a potential source of fear for cattle when designing handling equipment. Current literature does not offer guidelines for the design of equipment with regard to SPL. It is, however, recommended that handling equipment should be designed to minimize the SPL during handling. The purpose of this experiment was to measure stress levels in a group of cattle which were subjected to a series of varying sounds in order to determine a design threshold limit for handling equipment. Treatments included two frequencies, 1 kHz and 8 kHz, and three intensities, 40, 80, and 120dB. These treatments were assigned to the cattle using a completely randomized two by three factorial design replicated three times for a total of 18 animals being tested. A computer generated noise at each level was played back to the animals once a week for 6 weeks. Stress levels were measured using both physiological (heart rate and eye temperature) and physical (sudden movement) measures. Experiments yielded mixed results and did not prove that any of the sound pressure levels tested had any great effect on the stress level of the cattle.

Pretreatment is an essential step in biofuel production from lignocellulose. Disruption of the lignin structure gives enzymes and fermentation organisms access to long chains of cellulose and hemicellulose. For this project’s purposes, the pretreatment must work within the framework of an on-farm butanol bioprocessing facility. Alkaline hydrogen peroxide (AHP) is a delignification method that potentially provides several advantages. At the alkaline pH, powerful hydroxyl radicals are formed; which attack lignin. The objectives of this study were to determine if AHP removes substantial lignin for the feedstocks, corn stover, wheat straw, switchgrass and miscanthus, and to determine if AHP acts as a biocide? Compositional analysis determined if lignin was removed and HPLC data were used to determine whether or not Clostridium thermocellum hydrolyzed the pretreated material. Sterility was determined by plating the AHP material. All materials showed approximately 10% lignin removal with AHP. AHP increased structural carbohydrate concentrations for wheat straw, switchgrass and miscanthus. Corn stover showed no benefit from adding peroxide to a traditional alkaline pretreatment. AHP appears to suppress visible microbial growth for the first 24 hours after pretreatment. If AHP does not provide the additional hygienic effects, AHP does not provide a significant advantage over sodium hydroxide pretreatment.

Solid substrate cultivation (SSC) using lignocellulosic non-food feedstock, such as switchgrass, is an alternative for advanced biofuel production. Acetone-Butanol-Ethanol (ABE) fermentation in two stages using a sequential culture of microorganisms from the class Clostridia is an approach proposed to increase the butanol production. The goal was to test the efficacy of a sequential culture on high solid substrate cultivation in batch and continuous cultivation, and to evaluate conditions to optimize butanol production using switchgrass as substrate. Initial batch experiments were used to determine particle size effect, choice of solvent producer and pretreatment evaluation: The effect of particle size on gas production was surface area-dependent, 2 mm particle size of switchgrass was better fermented by clostridia than the other particle sizes. C. thermocellum improved switchgrass fermentation by C. beijerinckii. Moreover, C. saccharoperbutylacetonicum produced the highest butanol yield on glucose as substrate. The Fenton reaction was studied as a potential pretreatment for switchgrass. C. beijerinckii grew better on Fenton-treated material, but solvent production was low. The major conclusion of the continuous flow on SSC experiment was that there is no statistical difference in the effect of flow rate within the flow range tested.

Transportation costs represent a significant role in the economics of packaged hay and biomass crops. The material’s low bulk density limits transportation efficiency. Density is currently limited by the ability of the baling twine to withstand the expansion forces generated by the baled material shortly after it is ejected from the bale chamber. It was hypothesized that compromising the structure of the plant, particularly the plant nodes could reduce the amount of energy stored in the material as it is compressed and thereby reduce the material’s elastic response to compression. Literature pertinent to the biomass material’s behavior in compression was reviewed. Bulk samples of switchgrass and miscanthus were subject to uniaxial compression, and the required pressure needed to obtain a target density of 256 kg/m3 was compared on a wet and dry density basis. Both switchgrass and miscanthus showed a statistically significant decrease in the required compression pressure, and the interaction between the moisture level and required pressure was also significant. Existing models for the pressure density relationship of compressed bulk material were evaluated for suitability. Individual nodes and internode sections were subject to radial compression and the apparent modulus of elasticity and maximum contact stress were determined.

Precisely measuring the flow rate in sprayers is a key technology to precision agriculture. With the development of advanced technologies, the demand for the ability to measure flow rate of individual nozzle has become more important and urgent. This paper investigates the possibility of developing a low-cost flow rate measurement technique. The technique is based on analyzing the acoustic signal from a microphone placed near the nozzle tip. A comparison between acoustic signal and vibration signal was made to study the relations between them. Then several possible locations of the microphone for measuring flow rate were tested and compared, and one has been chosen as the best location. After that, two methods of analyzing data were proposed, one that could better describe the original curve was chosen. With all of that work done, further experiments were conducted on a variety of nozzle tips. The results showed that an acoustic sensor could be used as an indicator of flow rate from a nozzle, but that unique calibrations for different nozzle tips would be necessary.