Thesis (M. Eng.). / Written for the Dept. of Civil Engineering and Applied Mechanics. Title from title page of PDF (viewed 2008/07/29). Includes bibliographical references.

Thesis (M.S.)--University of Missouri, School of Mines and Metallurgy, 1922. / The entire thesis text is included in file. Typescript. Illustrated by author. Title from title screen of thesis/dissertation PDF file (viewed June 10, 2009)

Thesis (M.Eng.). / Written for the Dept. of Civil Engineering and Applied Mechanics. Title from title page of PDF (viewed 2008/07/29). Includes bibliographical references.

The crystallization kinetics of sodium sulphate from 9N sulphuric acid was studied under cooling conditions. The crystal growth and nucleation rates were determined using the Population Balance concept in a continuous mixed-suspension mixed-product-removal (MSMPR) crystallizer. The effects of supersaturation, crystal suspension density and temperature on the crystallization kinetics were all investigated. The study was conducted at crystallizer temperatures of 45, 50, 55, and 60 °C. The crystal growth rate data were correlated to the supersaturation with a power-law, G = KGSg. The crystal nucleation rate data were fitted to both primary (B° = KBSb) and secondary (B° = KNMTjSu) nucleation models. Growth and nucleation rate data were correlated according to the primary (B° = KbGi) and secondary (B° = KnMTjGv) relative kinetic models. The study determined that the growth rate data fit the expression, (G = KGS⁰‧⁸⁷ ), and that secondary nucleation was the dominant mode of nuclei generation (B° = KNMT⁰‧⁸⁴S¹‧²⁷). The sodium sulphate crystallizes from solution as the acid salt, sodium sesqui-sulphate (Na₃HSO₄) . The rate constants, KG and KN, were both functions of temperature and were fitted to Arrhenius type expressions : [formula omitted] / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

No description available.

Five cation exchange membranes and four anion exchange membranes were tested in a three-compartment, two-membrane, electrolysis salt-splitting cell for the recycle of sodium sulfate into sodium hydroxide and sulfuric acid. The cell is further examined using DuPont Nafion 324 cation exchange membrane and Sybron Ionac MA-7500 anion exchange membrane to determine the maximum concentration of sodium hydroxide that can be produced by electrolysis salt-splitting as well as to determine the chief source of inefficiency. The discussion includes recommendations for future electrolysis salt-splitting cells and a mathematical model of the cell is created to determine optimum operating conditions.

Thesis (Ph. D.)--University of Chicago, 1940. / Reproduced from type-written copy. "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois." Includes bibliographical references.

No description available.

No description available.

Orientador: José Vicente Hallak d'Angelo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-16T22:26:39Z (GMT). No. of bitstreams: 1 Andreuccetti_MelissaTatiana_M.pdf: 3177763 bytes, checksum: 23a4cec530fa31832c045e89474dbdde (MD5) Previous issue date: 2010 / Resumo: O cozimento da madeira é a etapa do processo Kraft onde é feita a separação das fibras celulósicas dos demais compostos orgânicos da madeira. A solução utilizada nessa etapa, denominada licor branco, contém hidróxido e sulfeto de sódio gerando, após o cozimento, um resíduo chamado licor negro fraco com concentração entre 15 e 18% de sólidos (em massa). Este licor é enviado à planta de evaporação que tem por finalidade concentrá-lo aumentando o teor de sólidos para valores entre 64 e 75% em massa. Durante a etapa de concentração do licor negro ocorre a precipitação de sais de sódio, que estão completamente dissolvidos quando o licor encontra-se em concentrações inferiores a 45 - 50% de sólidos secos. Quando o licor é concentrado para valores acima de 50% estes sais começam a precipitar, sendo que o limite de solubilidade dos mesmos é definido como a concentração exata na qual estes sais começam a precipitar. O objetivo do presente trabalho consistiu, inicialmente, em validar uma metodologia de análise do sulfato de sódio e avaliar a sua reprodutibilidade. Também foram realizadas análises do teor de sólidos, massa específica e viscosidade. Após a realização de todas as análises, realizou-se um estudo estatístico para a avaliação do comportamento de cada parâmetro obtido experimentalmente e a correlação entre eles. Foi realizada também a avaliação do comportamento entre os parâmetros. Para todas as análises utilizaram-se amostras de licor negro de eucalipto com concentrações diferentes de sólidos (15 %, 29 % e 39 %). Todos os resultados obtidos experimentalmente da análise de sulfato de sódio possibilitaram a validação e a reprodutibilidade da técnica, que poderá ser aplicada a licores mais concentrados para determinar o teor de sulfato de sódio, buscando avaliar, posteriormente, sua influência na formação de incrustações nos evaporadores. Os resultados obtidos para teor de sólidos, massa específica e viscosidade também apresentaram valores coerentes, estando de acordo com a concentração e tipo de amostra analisada. Todos os parâmetros apresentaram boas correlações entre si / Abstract: Wood digestion is the stage in the Kraft process where the separation of cellulose fibers from other organic compounds is performed. The solution used in this stage, called white liquor, contains sodium and sulfide hydroxide generating, after the cooking, a residue called black liquor with a concentration between 15 and 18 % of solids. This liquor is sent to the evaporation plant which aims to concentrate it by increasing solids content to the range of 64 to 75 % by weight. During this stage of black liquor, occurs the precipitation of sodium salts that are completely dissolved when the liquor is at concentrations below 45 - 50 % of dry solids. When the liquor is concentrated to values above 50 % of solids these salts begin to precipitate and the solubility limit thereof is defined as the exact concentration at which these salts begin to precipitate. The objective of this work was, initially, to validate a methodology for sodium sulfate measure analysis and evaluate its reproducibility. Analysis to solids content, specific mass and viscosity were also performed. After completion of all tests, a statistical study was made to evaluate the behavior of each parameter obtained experimentally and a correlation between them was established. All analyzed samples of eucalyptus black liquor were used with different concentrations of solids (15 %, 29 % and 39 %). All experimental results of the analysis of sodium sulfate have allowed the validation and reproducibility of the technique that may now be applied to more concentrated liquors to determine the content of sodium sulfate, allowing a study of its influence on scale formation in evaporators. The results obtained for solids content, specific mass and viscosity have also shown consistent values, in agreement with the concentration and type of sample analyzed. Good correlations between parameters were showed / Mestrado / Sistemas de Processos Quimicos e Informatica / Mestre em Engenharia Química