Thesis (M.S.)--University of Tennessee, Knoxville, 2009. / Title from title page screen (viewed on Oct. 23, 2009). Thesis advisor: James A. Larson. Vita. Includes bibliographical references.

Intensive biomass production in emerging bioenergy systems could increase nonpoint-source sediment and nutrient losses and impair surface and groundwater quality. Recycling biochar, a charcoal byproduct from pyrolysis of biomass, provides potential sources of mineral nutrients and organic carbon for sustaining biomass productivity and preserving soil and water. Yet, research is needed to verify that recycling of pyrolysis biochars will enhance crop growth and soil and environmental quality similar to black carbon or biochar derived from burning of biomass in tropical or Terra Preta soils. The experimental design of this study consisted of 3 replications and four biochar rates (0, 4, 16, and 64 Mg ha-1) incorporated in both a sandy loam and clay soil with and without fertilizer sources of N, P, and K. The sandy loam and clay soils were studied in separate experiments within a set of 24 box lysimeters seeded with switchgrass. Simulated rain was applied at 50 percent and 100 percent establishment of switchgrass for each soil type. Runoff and leachate were collected and analyzed for total and dissolved N, P, K and organic C. After the second rain event, each soil type and the accumulated switchgrass was sampled and analyzed. In the Boonville soil, biochar applied at 64 Mg ha-1 decreased switchgrass emergence from 42 percent to 14 percent when compared to soil alone. In the Burleson soil, 64 Mg ha-1 biochar had no effect (P > 0.05) on biomass production or leaf area index (LAI). Fertilizer N, P, and K had no effect (P > 0.05) on switchgrass emergence for either soil, but did increase (P < 0.001) N, P, and K uptake, biomass production, and LAI. Increasing rates of biochar increased (P < 0.001) runoff concentrations of DRP during each rain event for both the Boonville and Burleson soils. Four rates of biochar receiving supplemental N, P, and K fertilizer also resulted in greater runoff concentrations of DRP. Emergence tests under increased heat showed electrical conductivities of soil-water solutions to be as high as 600 microS cm-1, even after biochar was washed with acetone and water to remove residual oils and tars and soluble salts. Increasing biochar rates decreased soil bulk density and increased pH and SOC in the 0- to 5-cm depth of soil. As a result of high nutrient recovery during pyrolysis (58 percent of total N, 86 percent of total P and 101 percent of total K), high rates of biochar applied at 64 Mg ha-1 increased mass losses of TN, TP, and TK from both soils. Yet, the mass balance of nutrients showed a surplus of N, P, and K at 64 Mg ha-1 biochar, which suggests some nutrient inputs are not plant available and remain in soil. Careful management of biochar, especially at high rates with these high nutrient contents, is critical when trying to improve soil fertility while protecting water quality.

Biomass from forestry and agricultural sources has recently drawn a lot of attention as a new source of feedstock for energy and bio products. Size reduction is an important step in preparation of biomass as a feedstock. Each conversion process needs its own specific size or size distribution of particles. Modeling the size reduction process helps to optimize the design and control of the process while ensuring biomass particle sizes for an efficient biofuel conversion process. The objective of this study was to apply the population balance method for modeling the size reduction process. The model was applied to switchgrass size reduction by a grinder. Two population balance parameters, grinding rate (s⁻¹) and breakage distribution function (dimensionless) were estimated using experimental grinding data. The time dependent balance equations were solved using the Euler technique. The accumulation and depletion of the particles belonging to each size category were simulated as a function of time. The simulation predicted the residence time of particles inside the grinder in a way that the ground particles could meet the size and size distribution specifications for the downstream process. The thesis also describes preliminary steps in size reduction. Ground particles were fractionated based on their size by sieving. Weibull distribution was found to be the best probability density function to fit the data.

Commercial cultivation of switchgrass in Ontario is limited mainly due to inadequate market opportunities. However, recent developments in bioproducts identify switchgrass as a promising biomass crop for bioenergy and biomaterials applications. At present assessment of environmental impact of growing switchgrass in Ontario is lacking. Therefore, this study was conducted to evaluate the energy use and environmental impacts of switchgrass biomass production in Ontario through life cycle assessment. Cradle to farm gate life cycle assessment was conducted following the ISO 14040/14044 guidelines. Life cycle inventory data were collected from farmers, experts and available literature. Life cycle impact assessment was conducted for energy use and environmental impact using the SimaPro software. Life cycle processes related to fertilization, harvesting and soil N emission were identified as major hot spots for energy and environmental impacts. Improving efficiency of energy, inputs and biomass yield will reduce the environmental burden associated with growing switchgrass in Ontario. / OMAFRA- UofG Highly Qualified schlorship programme and OMAFRA- UofG Partnership bioeconomy industrial uses reaserch theme project funding.

Biomass from forestry and agricultural sources has recently drawn a lot of attention as a new source of feedstock for energy and bio products. Size reduction is an important step in preparation of biomass as a feedstock. Each conversion process needs its own specific size or size distribution of particles. Modeling the size reduction process helps to optimize the design and control of the process while ensuring biomass particle sizes for an efficient biofuel conversion process. The objective of this study was to apply the population balance method for modeling the size reduction process. The model was applied to switchgrass size reduction by a grinder. Two population balance parameters, grinding rate (s⁻¹) and breakage distribution function (dimensionless) were estimated using experimental grinding data. The time dependent balance equations were solved using the Euler technique. The accumulation and depletion of the particles belonging to each size category were simulated as a function of time. The simulation predicted the residence time of particles inside the grinder in a way that the ground particles could meet the size and size distribution specifications for the downstream process. The thesis also describes preliminary steps in size reduction. Ground particles were fractionated based on their size by sieving. Weibull distribution was found to be the best probability density function to fit the data.

Thesis (Ph.D.)--Virginia Commonwealth University, 2009. / Prepared for: Dept. of Chemical and Life Science Engineering. Title from title-page of electronic thesis.

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2008. / Title from title screen (site viewed Feb. 17, 2009). PDF text: 196 p. : ill. (some col.) ; 2 Mb. UMI publication number: AAT 3324854. Includes bibliographical references. Also available in microfilm and microfiche formats.

Biomass from forestry and agricultural sources has recently drawn a lot of attention as a new source of feedstock for energy and bio products. Size reduction is an important step in preparation of biomass as a feedstock. Each conversion process needs its own specific size or size distribution of particles. Modeling the size reduction process helps to optimize the design and control of the process while ensuring biomass particle sizes for an efficient biofuel conversion process. The objective of this study was to apply the population balance method for modeling the size reduction process. The model was applied to switchgrass size reduction by a grinder. Two population balance parameters, grinding rate (s⁻¹) and breakage distribution function (dimensionless) were estimated using experimental grinding data. The time dependent balance equations were solved using the Euler technique. The accumulation and depletion of the particles belonging to each size category were simulated as a function of time. The simulation predicted the residence time of particles inside the grinder in a way that the ground particles could meet the size and size distribution specifications for the downstream process. The thesis also describes preliminary steps in size reduction. Ground particles were fractionated based on their size by sieving. Weibull distribution was found to be the best probability density function to fit the data. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

Loblolly pine (Pinus taeda) plantations are a common land use of the southeastern United States that have the potential to function as a source of cellulosic biomass for biofuel production. A novel land use practice of intercropping switchgrass (Panicum virgatum) between planted loblolly pines has been developed as a potential method of cellulosic biomass production. I evaluated response of arthropods and breeding birds to intercropping switchgrass within loblolly pine plantations compared to typically managed pine plantations. I detected 13 arthropod orders and 44 breeding bird species during 2014 – 2015. Intercropping switchgrass reduced arthropod diversity and evenness, with richness not affected. Arthropod abundance response to intercropping switchgrass varied among orders. Breeding bird species did not respond differently to intercropping switchgrass compared to typically managed pine. Continued assessment is needed to provide greater insight regarding potential effects of this land use practice throughout a rotational period.

Switchgrass (Panicum virgatum) is a native warm-season grass where weed control during establishment is a limiting factor for stand. Objectives of this research are to develop a herbicide resistant cultivar and to test a variety of seed safeners to improve first year growth. Phenotypic recurrent selection (PRS) was used to select ‘Alamo’ switchgrass seedlings that showed resistance to imazapic herbicide at 245 g a.i./ha. Initial screenings of 364, 650 seedlings resulted in 63 survivors, a selection intensity of 0.0172%. Subsequent testing of the next generation of seedlings indicated that multiple generations of selection were needed in order to transfer greater resistance to the offspring. Seed safener testing consisted of three trials. Field data taken included emergence counts, weed control ratings, and end of season harvest. Results showed fluxofenin (a.i. in Concep III) as being only safener providing protection against metolachlor (83.7% a.i.).