Selection of mixed solvent for crude caprolactam extraction

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27710%2F24%3A10256134" target="_blank" >RIV/61989100:27710/24:10256134 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Selection of mixed solvent for crude caprolactam extraction

Original language description

Contribution (POSTER) 27th International Congress of Chemical and Process Engineering CHISA, 25.-29.8.2024, Praha.Caprolactam is the precursor of Nylon 6, a widely used synthetic polymer. Most of the worldwide production of caprolactam is synthetized from cyclohexanone by the Beckmann rearrangement. The purity requirements of caprolactam are extremely stringent because even a small amount of impurities greatly affect the physical-mechanical properties of Nylon 6. Since both polar and nonpolar impurities are present in the crude caprolactam, pure caprolactam is obtained in the so-called forward-extraction using a nonpolar organic solvent, such as trichlorethylene, benzene or toluene followed by back-extraction with water followed by multistage distillation.Mixed solvents containing 1-octanol and 1-heptanol, promising alternatives to toxic trichlorethylene in caprolactam extraction, were studied in this work using a real sample of crude caprolactam (70 wt.% caprolactam in water). Cyclohexane and n-heptane were selected for adjusting the solubility of chosen alcohols in the aqueous phase. The optimum concentration of alcohols in both mixed solvents was estimated by modelling using Hansen parameters of solubility and verified experimentally. 40 wt.% 1-octanol in heptane had the most similar caprolactam distribution coefficient as trichlorethylene. The L-L equilibrium data of the selected mixed solvents and their physical properties influencing mass transport (density, viscosity, and interfacial tension) were determined experimentally and used for the design of extraction columns for forward and backward extraction.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

20400 - Chemical engineering

Project

<a href="/en/project/FV40040" target="_blank" >FV40040: Continual purification of Caprolactam.</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů