| 摘要 |
PURPOSE:To obtain a high-purity tar acid from an oil phase, by extracting a tar acid with an alkali, decomposing a crude tar acid salt with a weakly acidic substance to give a crude tar acid, blending the crude tar acid with an aromatic hydrocarbon oil, and bringing them into contact with each other, so that impurities such as salts of inorganic acids and organic acids are transferred to a water layer and removed. CONSTITUTION:A tar acid raw material such as tar oil, coal liquefied oil, coal gasified condensate, etc., is extracted with an alkali, the prepared crude tar acid salt is decomposed with a weakly acidic substance such as a carbonic acid gas, etc., to give hydrous crude tar acid, 100pts.vol. of the crude tar acid is blended with 70-300pts.vol. aromatic hydrocarbon oil, preferably xylene 4, and brought 3 into contact with each other. Then, the prepared mixed solution is separated 5, 8 and 11 into a water phase and an oil phase, impurities in the crude tar acid are transferred into the water phase and removed, and the oil phase is distilled to give a high-purity tar acid containing no impurities, Preferably the aromatic hydrocarbon oil recovered together with the tar acid from the oil phase is circulated and used.
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