液相二甲苯之空氣氧化

Liquid-Phase Catalytic Air Oxidation of Xylenes

曹福湧(Fu-Youg Chao)

《化學》 49年1期 (1960/03) Pp. 21-27

https://doi.org/10.6623/chem.1960002

摘要

二甲苯以空氣液相氧化，反應溫度130-140°C在氧化初期6小時，吸收氧氣情形良好，以後吸收氧氣速度逐漸降低。氧化18小時以後，生成之甲苯酸尚能溶於液體內，至24小時後，冷却即有大量沈澱，空間速度以3.8為宜。觸媒鈷鹽比錳或鉛為優。松香鈷用量為二甲苯之0.1-0.4%。試作半連續氧化，結果得少量之苯二甲酸及大部的之甲苯酸。以含氧60%之富氧空氣氧化二甲苯，損失較少。氧化溫度在120°C時，氧化速度已快，產品顏色較白。135°C時，氧化產品顏色較黃，產率高達82.2%（包括苯二甲酸及甲苯酸）。二甲苯以富氧作半連續氧化，結果與用純空氣者大致相同，大部份產品亦為甲苯酸。

並列摘要

Air was passed through a liquid phase reaction mixture of xylenes and a catalyst, at 130-140°C. The reaction: proceeded smoothly at the start; after the reaction had begun for six hours, the rate of absorption of oxygen began to drop gradually. It was found that colored'salts were better catalysts; among those; cobalt salt was more effective than saIt of manganese or of lead. The quantity of cobalt rosinate employed should be 0.1-0.4% of that of the xylenes. A space velocity of 3S per minute was found to be preferable. The oxidation products were mainly toluic acids with a little amount of phthalic acids (inluding tere and iso-phthalic acids). Better results were obtained when air containing .60% oxygen was used in place of atmospheric air. Oxidation took place spontaneousy and vigorously at 120°C; the product was nearly white in color. When oxidation was conducted at 135°C, the product became yellowish; the yield reached was 82.2% Semi-continuous oxidation prcoess was employed, the result of that, by using oxygen-enriched air, was somewhat similar to that obtained by using atmospheric air. The resulting products were mainly toluic acids.