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Characterization And Quantification Of Monomers, Oligomers, And By-Products From Xylan During Biomass Pretreatment, Ching-Shuan Lau

Graduate Theses and Dissertations

Biomass pretreatment generates inhibitory products, which reduce the overall yield of xylose for ethanol production. Understanding of hemicellulose depolymerization into xylose is essential to identify the pretreatment conditions that maximize xylose formation, but minimize the generation of these inhibitory products, such as formic acid and furfural. Thus, the goal of this project is to understand how dilute acid pretreatment parameters affect hemicellulose depolymerization, maximize xylose concentrations, and minimize by-products formation.

To progress towards this goal, rates and mechanisms of hemicellulose release must be determined. Birchwood xylan was used as the starting material to produce xylose oligomers. The hydrolyzed birchwood xylan …

Optimization Of A Dynamic Hot Water Pretreatment Of Switchgrass Using Catalysis By Carbonation To Maximize Carbochemical Yields, Rohit Tanaji Dhamdere

Graduate Theses and Dissertations

A bio-refinery is a facility that converts renewable bio-resources into value-added chemicals and products. In this context of a bio-refinery, the production of the carbochemicals such as HMF, furfural and organic acids illustrate that multiple products can be produced from a renewable source such as lignocellulosic biomass (switchgrass). Traditionally, carbochemicals such as furfural and HMF are produced using inorganic acids such as H2SO4, HCL, and H3PO4. The use of such acids requires the application of high cost materials of construction such as Hastelloy-C, titanium etc.

The objective of this study is to develop a semi-continuous process for the conversion of …

Biomass And Lipid Production From Heterotrophic And Mixotrophic Fed-Batch Cultivations Of Microalgae Chlorella Protothecoides Using Glycerol, Shwetha Sivakaminathan

All Theses

Chlorella protothecoides is a microalga that can grow both photo-autotrophically and/or heterotrophically under different culture and environmental conditions. In this study both the heterotrophic growth and mixotrophic growth have been conducted. The heterotrophic experiments were conducted completely in the dark while the mixotrophic experiments had the dark cycles with periodic light exposure. The aim of the study was to independently understand the effect of each mode on biomass and lipid yields.
For the heterotrophic experiments, glycerol was used as an external organic carbon source while yeast extract was used as the nitrogen source. The carbon and nitrogen source were added …

Production Of Green Aromatics And Olefins From Lignocellulosic Biomass By Catalytic Fast Pyrolysis: Chemistry, Catalysis, And Process Development, Jungho Jae

Open Access Dissertations

Diminishing petroleum resources combined with concerns about global warming and dependence on fossil fuels are leading our society to search for renewable sources of energy. In this respect, lignocellulosic biomass has a tremendous potential as a renewable energy source, once we develop the economical processes converting biomass into useful fuels and chemicals.

Catalytic fast pyrolysis (CFP) is a promising technology for production of gasoline range aromatics, including benzene, toluene, and xylenes (BTX), directly from raw solid biomass. In this single step process, solid biomass is fed into a catalytic reactor in which the biomass first thermally decomposes to form pyrolysis …

Accuracy Of Biomass And Structure Estimates From Radar And Lidar, Razi Uddin Ahmed

Open Access Dissertations

A better understanding of ecosystem processes requires accurate estimates of forest biomass and structure on global scales. Recently, there have been demonstrations of the ability of remote sensing instruments, such as radar and lidar, for the estimation of forest parameters from spaceborne platforms in a consistent manner. These advances can be exploited for global forest biomass accounting and structure characterization, leading to a better understanding of the global carbon cycle. The popular techniques for estimation of forest parameters from radar instruments in particular, use backscatter intensity, interferometry and polarimetric interferometry. This dissertation analyzes the accuracy of biomass and structure estimates …

Pozzolanic Properties Of Biomass Fly Ash, Robert Lowe

All Theses

As biomass power production becomes more main stream, problems with waste disposal arise. Coal fly ash, a by-product of coal power production, has beneficial strength and durability properties when used as a cement replacement material. This study examined strength and durability characteristics of mortar and concrete samples containing biomass fly ash obtained from Craven County Wood Energy in North Carolina and examined methods of processing the material to enhance its pozzolanic characteristics.
The chemical and mineralogical compositions of the ash were determined using X-ray fluorescence (XRF), X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDS). The compositions met the requirements …

Life Cycle Assessment Of Biofuels Produced By The New Integrated Hydropyrolysis-Hydroconversion (Ih2) Process, Edwin Maleche

Dissertations, Master's Theses and Master's Reports - Open

Biofuels are alternative fuels that have the promise of reducing reliance on imported fossil fuels and decreasing emission of greenhouse gases from energy consumption. This thesis analyses the environmental impacts focusing on the greenhouse gas (GHG) emissions associated with the production and delivery of biofuel using the new Integrated Hydropyrolysis and Hydroconversion (IH²) process. The IH² process is an innovative process for the conversion of woody biomass into hydrocarbon liquid transportation fuels in the range of gasoline and diesel.

A cradle-to-grave life cycle assessment (LCA) was used to calculate the greenhouse gas emissions associated with diverse feedstocks …

Advanced Nanostructured Electro-Catalysts For Electricity Generation And Biorenewable Alcohol Conversion, Zhiyong Zhang

Dissertations, Master's Theses and Master's Reports - Open

In my Ph.D research, a wet chemistry-based organic solution phase reduction method was developed, and was successfully applied in the preparation of a series of advanced electro-catalysts, including 0-dimensional (0-D) Pt, Pd, Au, and Pd-Ni nanoparticles (NPs), 1-D Pt-Fe nanowires (NWs) and 2-D Pd-Fe nanoleaves (NLs), with controlled size, shape, and morphology. These nanostructured catalysts have demonstrated unique electro-catalytic functions towards electricity production and biorenewable alcohol conversion.

The molecular oxygen reduction reaction (ORR) is a long-standing scientific issue for fuel cells due to its sluggish kinetics and the poor catalyst durability. The activity and durability of an electro-catalyst is strongly …

Preprocessing Of Biomass Using Mechanical, Chemical And Microbial Techniques, Swetha Mahalaxmi

Electronic Theses and Dissertations

Biomass-derived fuels have acquired a lot of attention recently due to increasing emphasis on energy independence, efforts to utilize abundance of green resources and mitigation of greenhouse gas emissions. Grasses, agricultural residues, animal residues and waste, used oils, etc., can be used as starting materials in the production of biofuels. Various preprocessing techniques used in the preprocessing of biomass, such as microbial preprocessing, mechanical preprocessing and chemical pretreatment, are used for enhancing the digestibility of biomass to sugars for ethanol production. In this work, studies were conducted to improve the microbial, chemical and mechanical preprocessing of switch grass by decreasing …

Economic Modeling & Optimization Of A Region Specific Multi-Feedstock Biorefinery Supply Chain, William H. Faulkner

Theses and Dissertations--Manufacturing Systems Engineering

The objective of this thesis is to include strategic and tactical level decisions into the biorefinery supply chain design for a specific region while comparing multiple conversion technologies and biomass feedstocks. The allocation of biomass feedstocks, products, and the respective supply chain configuration locations are determined while ensuring the regions monthly biomass availability and product market demand constraints are met. This research considers all actions required to bring the bio-based products to market from harvesting, storing, and processing the biomass to market distribution. Two different conversion technologies are chosen for comparison: one advanced conversion technology and one conventional technology. Potential …

Development Of Cost-Effective And Benign Lipid Extraction System For Microalgae, Javed Iqbal

LSU Doctoral Dissertations

A laboratory-made continuous flow lipid extraction system (CFLES) was devised to extract lipids from microalgae Nannochloropsis sp., a potential feedstock for biodiesel fuel, with a focus to assess the workable temperatures and pressures for possible scale-up applications. Using conventional solvents, the CFLES recovered 100% of the lipids recovered with conventional Soxhlet extraction (USEPA method 3540) at moderate 50 psi pressure and 100°C temperature; conditions significantly lower than those normally used in pressurized liquid extractions requiring specialized equipment. Approximately 87% of the extracted oil was successfully transesterified into biodiesel fuel. For exploring the solvent potential of biodiesel, CFLES was also tested …