Verfahren zur Herstellung von Benzolcarbonsaeuren

摘要

1,264,815. Benzene carboxylic acids. BADISCHE ANILIN- & SODA-FABRIK A.G. 10 July, 1969 [11 July, 1968], No. 34830/69. Heading C2C. Benzene carboxylic acids are prepared by reacting a benzene substituted by one or more alkyl, hydroxyalkyl or formyl groups with molecular oxygen in the liquid phase in a reaction zone in the presence of a heavy metal catalyst, an activator selected from bromides, peroxides or bromide- or peroxide-forming compounds and an alkane carboxylic acid at elevated temperature and pressure, wherein a vapour phase effluent is withdrawn from the reaction zone and fractionated at substantially reaction zone pressure, the vapour phase from the fractionation step is cooled to below 80‹ C. and at least 30‹ C. below reaction temperature but not below ambient temperature so as to form a condensed organic phase, a condensed aqueous phase and uncondensed material, the condensed organic phase is returned to the reaction zone, water is removed from the condensed aqueous phase to balance substantially the water formed in the reaction zone and the remainder of the aqueous phase is returned to the reaction zone, and uncondensed material from the fractionation is recycled as recycle gas to the liquid phase in the reaction zone.