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Full-Text Articles in Engineering
Homogeneous Reaction Kinetics Of Carbohydrates With Viologen Catalysts For Biofuel Cell Applications, Hilary Bingham
Homogeneous Reaction Kinetics Of Carbohydrates With Viologen Catalysts For Biofuel Cell Applications, Hilary Bingham
Theses and Dissertations
Energy usage is continually on the rise and significant efforts are being extended to provide more renewable energy. One area of exploration is the development of fuel cells, which includes biofuel cells that can extract energy from carbohydrates obtained from biomass. Recently, viologen catalysts have been shown to enhance reaction rates of energy extraction and improve carbohydrate conversion efficiencies. However, characterizing the effects of process parameters such as pH, reactant concentrations, and carbohydrate exposure time to buffer solutions with a rigorous model is lacking. This thesis characterizes the homogeneous reaction between carbohydrates and a methyl viologen catalyst to provide insights …
Renewable Carbon From Lignin Biomass And Its Electrode And Catalyst Applications In Batteries, Supercapacitors, And Fuel Cells, Muslum Demir
Renewable Carbon From Lignin Biomass And Its Electrode And Catalyst Applications In Batteries, Supercapacitors, And Fuel Cells, Muslum Demir
Theses and Dissertations
Over the last century, almost all of the carbon materials developed for the energy industry are derived from fossil fuels. The growing global concerns about energy needs, fossil fuels consumption, and the related environmental issues have motived scientists to find new, green and sustainable energy resources such as the wind, solar and biomass energy. Essentially, biomass-derived materials can be utilized in energy storage and conversion devices such as Li-ion batteries, fuel cells, and supercapacitors. Among the biomass resources, lignin is a high volume byproduct from the pulp and paper industry and is currently burned to generate electricity and steam. The …
Quantifying Individual Losses In A Direct Methanol Fuel Cell, Jennifer Rae Ruffing
Quantifying Individual Losses In A Direct Methanol Fuel Cell, Jennifer Rae Ruffing
Theses and Dissertations
The performance of a direct methanol fuel cell (DMFC) is complicated due to the complex interactions of kinetic and transport processes. As a result, changes in one aspect of the cell have consequences in other aspects, which are difficult to elucidate from the full-cell polarization (i.e. voltage vs. current) behavior that fuel cell researchers often use to characterize the performance of their systems. The objective of this work was to develop a strategy to use current and voltage relationships from anode half cells, cathode half-cells, and a hydrogen pump, coupled with methanol crossover data and a mathematical model, to quantify …
Immobilized Viologen Polymer For Use In Direct Carbohydrate Fuel Cells, Yining Pan
Immobilized Viologen Polymer For Use In Direct Carbohydrate Fuel Cells, Yining Pan
Theses and Dissertations
Glucose and other carbohydrates are some of the most abundant renewable energy sources in the world. The oxidation of carbohydrates in a fuel cell allows their chemical energy to be converted directly into electrical energy. Viologen has been indentified and shows promising ability as an electron-transfer catalyst or mediator for carbohydrate oxidation in an alkaline carbohydrate fuel cell. Building on the previous results, the objective of this work was to develop an immobilization chemistry of viologen onto an electrode and to investigate the catalytic activity for carbohydrate oxidation in direct carbohydrate fuel cells.The immobilization was achieved by electropolymerizing a novel …
The Effect Of Bi-Polar Plate And Membrane Materials On Water Transport In Pemfcs, Visarn Lilavivat
The Effect Of Bi-Polar Plate And Membrane Materials On Water Transport In Pemfcs, Visarn Lilavivat
Theses and Dissertations
An analysis of liquid water transport and removal in Proton Exchange Membrane Fuel Cells (PEMFCs) as affected by different membranes and the geometry and surface roughness of bipolar plates on is presented. Four topics are considered. First, the channel dimension and shape of various flow fields have been shown to affect the cell performance and the uniformity in the distributions of current. Typical variations in the channel width, height, and undercut that may occur with manufactured metal plates are studied. These sample-to-sample variations and distributions are studied and compared with laboratory-scale graphite plates. The goal of the work is to …
Homogeneous Viologens For Use As Catalysts In Direct Carbohydrate Fuel Cells, Dane C. Hansen
Homogeneous Viologens For Use As Catalysts In Direct Carbohydrate Fuel Cells, Dane C. Hansen
Theses and Dissertations
Deriving electrical energy from glucose and other carbohydrates under mild conditions is an important research objective because these biomolecules are abundant, renewable, and can provide 12 to 24 electrons per molecule, yielding substantial electrical power. It was previously observed that disubstituted viologens, salts of N,N'-disubstituted 4,4'-bipyridine, are able to oxidize glucose under alkaline conditions. Building on that initial result, the objective of this work was to understand and quantify the effectiveness and utility of viologens as catalysts for use in direct carbohydrate fuel cells.The extent that viologens oxidize carbohydrates, the conditions under which that oxidation occurs, and the mechanism for …