Engineering Commons^™

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 …

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 …

Goali: Multicomponent Molecular Transport In Nanoporous Materials, Douglas M. Ruthven, David Sholl, Ronald Chance

University of Maine Office of Research Administration: Grant Reports

In recent years novel diffusion controlled catalytic processes and non-conventional separation processes such as adsorption and membrane processes have gained an increasingly important place in the petroleum and petrochemicals industries. Several factors have driven this trend, including the need to improve the energy efficiency and throughput of refineries, stricter limits on the allowable composition of gasoline and diesel fuel requiring the removal of aromatics and sulfur containing compounds to extremely low levels, the need to process increasingly complex deposits of both natural gas and liquid hydrocarbons, and the possibility of producing liquid fuels from non-traditional sources such as biomass. Although …

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 …

Prediction Of Tar And Light Gas During Pyrolysis Of Black Liquor And Biomass, Thomas H. Fletcher, Harland R. Pond, Jarom Webster, Judson Wooters, Larry L. Baxter

Faculty Publications

A generalized model for describing the pyrolysis behavior of low-grade fuels is being developed for incorporation into larger combustion simulation models. Light gas and tar yields from black liquor or biomass pyrolysis can be predicted using the chemical percolation devolatilization (CPD) model originally developed for coal. The initial approach is to measure the average chemical structures in a black liquor sample using 13C NMR spectroscopy. These chemical structures are then used in pyrolysis model predictions. With few changes from the coal-derived kinetic parameters, the model describes the organic pyrolysis behavior of black liquor samples obtained in a nitrogen-purged furnace. It …