Thesis (Ph. D.)--University of Wisconsin--Madison, 1972. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 214-217).

Thesis (M.S.)--University of Wisconsin--Madison, 1969. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 59-64). Also available on the World Wide Web.

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Supervisor: Gary T Rochelle. Vita. Includes bibliographical references.

Thesis (Ph. D.)--Pennsylvania State University. / Vita.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Inclludes bibliography.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1982. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 498-507).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1982. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 352-356).

In the pulp and paper industry, the interaction between the gas, liquid, and solid phases occurring in various unit operations is often not clearly understood. Such multi-phase operations include flotation deinking (a separation process of paper fibres in the recycling process) as well as the delignification and bleaching operations in the kraft pulping process. Much of the design, operation, and optimization of such processing equipment are dependent upon past experience as well as trial-and-error methodologies. Pulp fibre suspensions possess a complex and unique rheology. The unpredictability of the behaviour of pulp suspensions at any given mass concentration is due to the bonding between the fibres resulting in network formation (which depends on suspension consistency) with this interaction creating complexity in fluid flow in various unit operations. This thesis describes the gas hydrodynamic behaviour and gas-liquid mass transfer characteristic in low- and medium-consistency pulp suspensions in batch operation. First, the hydrodynamic behaviour of the gas phase (air) in water and pulp suspensions having mass concentrations up to Cm = 7% is examined by visually observing and recording the bubble shape, size, and rise velocity in a rectangular channel. Results are obtained using a high-speed video camera. Second, the hydrodynamic behaviour is described in terms of the gas holdup along with axial and radial gas phase distributions in water and kraft pulp suspensions having mass concentrations between Cm = 0.5 and 9% in a batch-operated cylindrical bubble column. The gas holdup results are compared using three methods: the suspension height method, the pressure difference method, and the electrical resistance tomography (ERT) method. Finally, the volumetric gas-liquid mass transfer characteristic of air in water and kraft pulp suspensions having mass concentrations up to Cm = 4% is examined in the same bubble column in batch-operation using a dissolved oxygen probe. Experimental results were comparable to that in literature for water and for pulp fibre suspensions having Cm < 2%. The presence of fibres had a significant effect on the gas holdup and mass transfer characteristic with results providing insight on the limitations that exist in industrial pulp unit operations. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

<p> This dissertation describes an experimental study of the simultaneous mass transfer and chemical reaction at a plane liquid-liquid interface involving the saponification of simple esters transferring into aqueous caustic solutions. The transfer experiments were carried out with both liquid phases stirred and unstirred respectively.</p> <p> Special emphasis was placed on the stagnant-phase systems. Turbulent reaction layer propagation rates were measured for ester phases (pre-saturated with water) in contact wiith aqueous caustic solutions (at various concentration levels). The distortion of the moire pattern was used to indicate the position of the propagating layer front. The cause and nature of the turbulent layer were elucidated. An apparatus, capable of withdrawing small samples of the liquid with probes precisely located in the aqueous phase, was constructed. Experimental techniques were developed to measure the abnormal concentration profiles of the reactants and the products within the turbulent layer. From the component concentration distribution data, the turbulent layer thicknesses, the reaction zone (within the turbulent layer) thicknesses, the mass transfer rates, and the enhancement factors were deduced. The effects of turbulence in the aqueous phase were estimated in terms of the derived eddy diffusivities and of the differences between the experimentally measured and the theoretically predicted (by molecular diffusion with reaction equation) enhancement factors.</p> <p> In the steady state transfer study using stirring in both phases, transfer rate data and enhancement factor data were obtained for three formate-sodium hydroxide systems.</p> <p> In addition to the mass transfer studies, a preliminary investigation on the diffusion coefficient measurement in binary and ternary liquid systems employing the moire pattern method was carried out. A diffusion cell was designed and built to enable the quick acquisition of the experimental data with reasonable accuracy.</p> / Thesis / Doctor of Philosophy (PhD)