Oxidação catalítica de açúcares
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Tipo de produção
Dissertação
Data
2016
Autores
Lima, F. S.
Orientador
Poço, João Guilherme Rocha
Periódico
Título da Revista
ISSN da Revista
Título de Volume
Citação
LIMA, F. S. Oxidação catalítica de açúcares. 2016. 124 f. Dissertação (Mestrado em Engenharia Química) - Centro Universitário FEI, São Bernardo do Campo, 2016. Disponível em: <https://doi.org/10.31414/EQ.2016.D.127611>. Acesso em: 11 out. 2018.
Texto completo (DOI)
Palavras-chave
Oxidação,Ácido glucônico,Catalisadores
Resumo
A glicose tem atraído muita atenção como biomassa renovável para a síntese de produtos orgânicos, seja por meio de processos químicos ou biotecnológicos. Dentre os produtos industriais que podem ser obtidos a partir da glicose pode-se citar o ácido glicônico que devido a sua baixa toxicidade é utilizado na fabricação de bebidas e para realçar o sabor em alguns alimentos. O gliconato de sódio, é o principal derivado comercializado, o sal de sódio do ácido glicônico é formado pelo excesso de soda que foi adicionado ao meio reacional, para manter o pH alcalino durante a sua produção, tendo as mesmas aplicações citadas para o ácido glicônico. Neste trabalho, a glicose e a mistura de glicose e frutose foram submetidas à oxidação catalítica com ar utilizando o catalisador Pd-Pt-Bi/C comercial. Foram variados o pH e a temperatura com o intuito de avaliar as melhores condições para a formação do ácido glicônico/gliconato. O consumo de hidróxido de sódio foi monitorado durante os ensaios e a conversão da glicose foi determinada por estequiometria e por espectrofotometria e o conteúdo de ácido glicônico/gliconato foi determinado por cromatografia (HPLC). Observou-se que o pH de reação ótimo se situa em torno de 9,5 e a temperatura ótima por volta de 55 oC, e ainda que a frutose tem efeito benéfico na seletividade da reação.
Glucose has attracted much attention as a renewable biomass for the synthesis of organic products, whether through chemical or biotechnological processes. Among the industrial materials that can be obtained from glucose, it can be mentioned gluconic acid that due to its low toxicity is used in the production of beverages and enhance the flavor in some foods. Sodium gluconate that is sodium salt of gluconic acid is the main derivative marketed. It is formed by the excess of soda that was added to the reaction medium to maintain an alkaline pH during production, having the same applications cited to gluconic acid. In this study, glucose as well as a mixture of glucose and fructose were subjected to a catalytic oxidation with air using Pd-Pt-Bi/C commercial catalyst. The pH and temperature were varied in order to understand the best conditions for conversion of glucose into gluconic acid/gluconate salt. The consumption of sodium hydroxide solution was monitored during the test and the conversion of glucose was determined by stoichiometric relations and by spectrophotometry. The content of of gluconic acid/gluconate was determined by means of HPLC chromatography. It has been found that fructose has a beneficial effect on the selectivity of the reaction and that the best conditions were found at pH 9,5 and temperature 55 oC.
Glucose has attracted much attention as a renewable biomass for the synthesis of organic products, whether through chemical or biotechnological processes. Among the industrial materials that can be obtained from glucose, it can be mentioned gluconic acid that due to its low toxicity is used in the production of beverages and enhance the flavor in some foods. Sodium gluconate that is sodium salt of gluconic acid is the main derivative marketed. It is formed by the excess of soda that was added to the reaction medium to maintain an alkaline pH during production, having the same applications cited to gluconic acid. In this study, glucose as well as a mixture of glucose and fructose were subjected to a catalytic oxidation with air using Pd-Pt-Bi/C commercial catalyst. The pH and temperature were varied in order to understand the best conditions for conversion of glucose into gluconic acid/gluconate salt. The consumption of sodium hydroxide solution was monitored during the test and the conversion of glucose was determined by stoichiometric relations and by spectrophotometry. The content of of gluconic acid/gluconate was determined by means of HPLC chromatography. It has been found that fructose has a beneficial effect on the selectivity of the reaction and that the best conditions were found at pH 9,5 and temperature 55 oC.