| 摘要 |
Cresylic acids, e.g. phenol, cresols and xylenols, are recovered from an aqueous solution derived by contacting petroleum distillates with aqueous caustic alkali, by adjusting the pH of said solution to above 11 and below 12, then contacting said solution with dialkyl ether having from 2 to 6 carbon atoms in each alkyl group under liquid phase conditions, separating a liquid ether phase and recovering cresylic acids therefrom. Cracked or virgin petroleum distillates may be used boiling in the gasoline range, such as sour catalytically cracked naphtha, or in the range 350-600 DEG C. The caustic alkali specified is caustic soda. The pH is adjusted by adding acid or acid-reacting material such as sulphuric acid or carbon dioxide. Dialkyl ethers mentioned are diethyl, diisopropyl, ethylisopropyl and dibutyl ethers. The ether contacting may be continuous and countercurrent and conducted in a packed or perforated plate tower, at temperatures between 60 DEG and 100 DEG F. Cresylic acids are recovered from the ether solution by distillation. In examples, aqueous solutions obtained by extraction of sour catalytically cracked heavy naphtha with caustic soda solution are extracted at pH's of from 11 to 14 with diethyl ether to obtain cresylic acids, and the use of benzene, iso-octane and cyclohexane in place of diethyl ether is described by way of comparison.
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