Engineering Commons^™

Recirculating Calcium Hydroxide Solution: A Practical Choice For On-Farm High Solids Lignocellulose Pretreatment, William S. Sympson Jr.

Theses and Dissertations--Biosystems and Agricultural Engineering

Pretreatment is a necessary step in the utilization of lignocellulosic biomass for biochemical conversion to higher value products. There are multiple chemical choices for industrial settings, however on-farm choices are constrained to near ambient conditions with minimal specialized equipment, training, and limited waste disposal. Calcium hydroxide (lime) is suitable for on-farm use. This work presents the novel idea of pretreating biomass by recirculating a filtered, saturated lime solution in an up-flow, high solids (14-16% w/w) configuration at ambient conditions. In this system, lime solids were efficiently consumed, post-pretreatment washing of substrate did not significantly improve glucose yields, and energy and …

Automated Solid-Substrate Cultivation Of The Anaerobic Bacterium Clostridium Thermocellum, Mathew J. Ruwaya

Theses and Dissertations--Biosystems and Agricultural Engineering

The organism Clostridium thermocellum grows on cellulosic substrates and produces ethanol, acetate, lactate, formic acid, and CO₂. The organic acids produced alter the growth environment in which the bacteria grows and ultimately inhibit bacterial growth. One method which has been used successfully to maintain the system at acceptable growth conditions is to intermittently flush out the spent media and metabolic products and replace with new fermentation media. Our goal was to design and build an automated system that will automatically flush the spent media from the growing culture and resupply new media without manual intervention. An automated control …

Long-Term Effects Of Forestry Best Management Practices On Hydrology And Water Chemistry In Three Appalchian Headwater Catchments, Kameryn I. Wright

Theses and Dissertations--Biosystems and Agricultural Engineering

In 1982, a study was initiated in the Field Branch watershed, in the University of Kentucky’s Robinson Forest, to evaluate forestry best management practice (BMP) effectiveness after intensive harvesting. The study utilized a paired watershed approach on three adjacent Field Branch subcatchments. One subcatchment was left as the control, one had BMPs implemented (including a 50-ft undisturbed buffer along the stream), and one was clear-cut to the stream’s banks without the use of BMPs (i.e. logger’s choice). Prior research has shown that logging can negatively impact watershed functions by altering stream hydrology, geomorphology, water quality, and instream habitat. Thus, the …

Effectiveness Of Biochar Addition In Reducing Concentrations Of Selected Nutrients And Bacteria In Runoff, Rachel Williams

Theses and Dissertations--Biosystems and Agricultural Engineering

Land application and storage of horse manure and municipal sludge can increase nutrient and bacteria concentrations in runoff. Biochar increases soil nutrient retention when used as a soil amendment. The objectives of this study were to determine if biochar, when mixed with horse manure or sludge, affects runoff concentrations of total Kjehldahl nitrogen (TKN), ammonia-nitrogen (NH3-N), nitrate (NO3-N), total phosphorus (TP), dissolved phosphorus (DP), total suspended solids (TSS), chemical oxygen demand (COD), and fecal coliforms (FC). Horse manure and sludge were applied to 2.4 x 6.1 m fescue plots (six each), with three plots of each material amended with 5-8% …

Induction Of Cellulase In High Solids Cultivation Of Trichoderma Reesei For Enhanced Enzymatic Hydrolysis Of Lignocellulose, Danielle Empson

Theses and Dissertations--Biosystems and Agricultural Engineering

This project aimed investigated cellulase in-situ production for large-scale on-farm production of lignocellulosic biofuel. Cellulase activity and glucose released by T. reesei with corn stover and wheat bran as co-substrates for solid state cultivation (SSC) were examined. Co-cultivation has previously increased T. reesei cellulase, but corn stover and wheat bran have not been co-cultivated (Dhillon, Oberoi et al. 2011). This work compared cellulase activity and glucose concentration of corn stover co-cultivated with 0-40% wheat bran in high solids. Samples with at least 20% wheat bran exhibited increased cellulase activity. However, the average glucose concentration without wheat bran was 3.29 g/L …

Evaluation Of Flocculation, Sedimentation, And Filtration For Dewatering Of Algal Biomass, Nicholas A. Rhea

Theses and Dissertations--Biosystems and Agricultural Engineering

Algae can be used as a feedstock for agricultural fertilizers, livestock/poultry feeds, anaerobic digestion, and biofuel production. Regardless of the end product, water removal is necessary and difficult to do cost effectively. For each product the requirements for moisture content (or solids content) vary, such that a desirable water removal strategy would need to be adaptable to varying levels of water removal. Flocculation, with sedimentation and drying was evaluated as a possible strategy for algae dewatering. Anionic and nonionic flocculants are known to be ineffective at flocculating algal culture, which was confirmed for this case by electro-osmotic flow testing of …

Heat And Mass Transfer In Baled Switchgrass For Storage And Bioconversion Applications, Drew F. Schiavone

Theses and Dissertations--Biosystems and Agricultural Engineering

The temperature and moisture content of biomass feedstocks both play a critical role in minimizing storage and transportation costs, achieving effective bioconversion, and developing relevant postharvest quality models. Hence, this study characterizes the heat and mass transfer occurring within baled switchgrass through the development of a mathematical model describing the relevant thermal and physical properties of this specific substrate. This mathematical model accounts for the effect of internal heat generation and temperature-induced free convection within the material in order to improve prediction accuracy. Inclusion of these terms is considered novel in terms of similar biomass models.

Two disparate length scales, …

Development Of Regional And Hydraulic Geometry Curves For The Eastern Kentucky Coalfields, Ashlan Berry

Theses and Dissertations--Biosystems and Agricultural Engineering

Regional curves and hydraulic geometry curves relate bankfull channel dimensions to drainage area and bankfull discharge, respectively. These curves are used in the natural channel design process to help identify bankfull and to estimate bankfull dimensions of the design channel. Nineteen streams were surveyed to determine their bankfull parameters (cross-sectional area, width, mean depth, discharge, slope, and Manning’s n), along with 27 streams previously surveyed in other studies. The data were used to create regional and hydraulic geometry curves for three hydrologic landscape regions (HLR 9, HLR 11, and HLR 16, individually) in the Eastern Kentucky Coalfields (EKC) as well …