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Previous issue date: 2010-06-17 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Seeking a greater appreciation of cheese whey was developed to process the hydrogenation of lactose for the production of lactitol, a polyol with high added value, using the catalyst Ni /
activated carbon (15% and 20% nickel), the nitride Mo2N, the bimetallic carbide Ni-Mo/ activated carbon and carbide Mo2C. After synthesis, the prepared catalysts were analyzed by
MEV, XRD, laser granulometry and B.E.T. The reactor used in catalytic hydrogenation of lactose was the type of bed mud with a pressure (68 atm), temperature (120 oC) and stirring
speed (500 rpm) remained constant during the experiments. The system operated in batch mode for the solid and liquid and semi-continuous to gas. Besides the nature of the catalyst,
we studied the influence of pH of reaction medium for Mo2C carbide as well as evaluating the character of the protein inhibitor and chloride ions on the activity of catalysts
Ni (20%)/Activated Carbon and bimetallic carbide Ni-Mo/Activated Carbon. The decrease in protein levels was performed by coagulation with chitosan and adsorption of chloride ions was performed by ion exchange resins. In the process of protein adsorption and chloride ions, the maximum percentage extracted was about 74% and 79% respectively. The micrographs of the powders of Mo2C and Mo2N presented in the form of homogeneous clusters, whereas for the catalysts supported on activated carbon, microporous structure proved impregnated with small particles indicating the presence of metal. The results showed high conversion of lactose to lactitol 90% for the catalyst Ni (20%)/Activated Carbon at pH 6 and 46% for the carbide Mo2C pH 8 (after addition of NH4OH) using the commercial lactose. Monitoring the evolution of the constituents present in the reaction medium was made by liquid
chromatography. A kinetic model of heterogeneous Langmuir Hinshelwood type was developed which showed that the estimated constants based catalysts promoted carbide and
nitride with a certain speed the adsorption, desorption and production of lactitol / Visando, uma maior valoriza??o do soro de queijo desenvolveu-se o processamento de hidrogena??o da lactose para produ??o de lactitol, um p?liol de alto valor agregado,
utilizando os catalisadores Ni/Carv?o ativado (com 15% e 20% de n?quel), o nitreto Mo2N, o carbeto Mo2C e o carbeto bimet?lico Ni-Mo/Carv?o ativado. Ap?s a s?ntese, os catalisadores preparados foram analisados por MEV, DRX, granulometria a laser e B.E.T. O reator utilizado na rea??o de hidrogena??o da lactose foi do tipo leito de lama cuja press?o (68 atm), temperatura (120 oC) e velocidade de agita??o (500 rpm) permaneceram constantes durante os experimentos. O sistema operou em batelada para a fase s?lida e l?quida e semi-cont?nuo para a fase gasosa. Al?m da natureza do catalisador, foi estudada a influ?ncia do pH do meio
reacional para o carbeto Mo2C bem como a avalia??o do car?ter inibidor das prote?nas e ?ons cloretos na atividade dos catalisadores Ni(20%)/Carv?o ativo e o carbeto bimet?lico Ni-
Mo/Carv?o ativo. A diminui??o dos teores de prote?nas foi realizada atrav?s da coagula??o com quitosana e a adsor??o dos ?ons cloretos foi realizada atrav?s de resinas de troca i?nica.
No processo de adsor??o de prote?nas e dos ?ons cloretos, o percentual m?ximo extra?do foi em torno de 74% e 79% respectivamente. As micrografias dos p?s de Mo2C e Mo2N
apresentaram-se na forma de aglomerados homog?neos, enquanto que para os catalisadores suportados em carv?o ativo, a estrutura se mostrou microporosa com pequenas part?culas impregnadas indicando a presen?a do metal. Os resultados obtidos apresentaram ?ndices de convers?o da lactose em lactitol de 90% para o catalisador Ni(20%)/Carv?o ativo em pH 6 e de 46% para o carbeto Mo2C em pH 8 (ap?s adi??o de NH4OH) utilizando a lactose comercial. O acompanhamento da evolu??o dos constituintes presentes no meio reacional foi feito por cromatografia em fase l?quida. Um modelo cin?tico heterog?neo do tipo Langmuir- Hinshelwood foi desenvolvido cujas constantes estimadas evidenciaram que os catalisadores a base de nitreto e carbeto promoveram com certa velocidade a adsor??o, produ??o e dessor??o de lactitol
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/15896 |
| Date | 17 June 2010 |
| Creators | Vieira, Janine Reginaldo Guimar?es |
| Contributors | CPF:12270202449, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783510Y4, Souza, Carlson Pereira de, CPF:13681389420, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4781094H3, Oliveira, Jackson Ara?jo de, CPF:65331060587, http://lattes.cnpq.br/5058617634570704, Mendon?a, Fabiano Andr? de Souza, CPF:94196834434, http://lattes.cnpq.br/3456431841933671, Lima Filho, Nelson Medeiros de, CPF:36066397400, http://lattes.cnpq.br/6756450118042081, Fontes, Francisco de Assis Oliveira, CPF:20300190468, http://lattes.cnpq.br/9043538628554844, Sousa, Jo?o Fernandes de |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Engenharia Qu?mica, UFRN, BR, Pesquisa e Desenvolvimento de Tecnologias Regionais |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/embargoedAccess |
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