Extração de acidos carboxilicos atraves de membranas : (perstração)

AUTOR(ES)
DATA DE PUBLICAÇÃO

1995

RESUMO

Recovering or elimination of organic acids from dilute solutions is today a hard separation problem. They are main products in several chernical and food industry processes and may also act as inhibitors in other biomass processes. In this work, pertraction was introduced as an alternative method for organic acid separation. Pertraction is a dialytic extraction, conducted through selective dense membranes into a suitable stripping solution, from which the extracted component may be subsequently separated. Results of dialysis and pertraction experiments with different rnembranes are shown. Anionic exchange membranes showed the best performance. Sodium hydroxidc and amine solutions were used as stripping agents. The importance of OH¨ ions for the acid transport through the membrane was demonstrated. It was also shown that other ionic components may influence the acid flow. Pertraction experiments performed with different carboxylic acids showed that the membrane permeability decreases with increasing acid molecular volume. Results performed in the laboratory were reproduced on a larger scale, allowing for the work with 100 L feed volume and 0.4 m membrane. The results obtained in this work encouraged the use of pertraction for acid extraction in current separation problems. One real application was the extraction of acetic acid from n-hexanol. Another application investigated here was the connection of a pertraction system to a fermentation process for the extraction of acetic and propionic acids.

ASSUNTO(S)

acidos carboxilicos membranas (tecnologia) extração (quimica)

ACESSO AO ARTIGO

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