公开(公告)号：EP1311467B1

公开(公告)日：2009-06-24

申请号：EP01980252.9

申请日：2001-08-20

Applicant: BASF SE

Inventor： REUTER, Peter ,  VOIT, Guido ,  HEIDEMANN, Thomas

IPC: C07C51/265 ,  C07C51/31

CPC classification number: C07C51/265 ,  C07C51/313 ,  C07C63/16

Abstract: The invention relates to a method for producing phthalic anhydride by the gas phase oxidation of xylene, naphthalene or mixtures thereof in a multitube fixed-bed reactor, which is thermostatted by a heat-transfer medium, on two different fixed-bed catalysts arranged in layers. The invention method is carried out in such a manner that the maximum temperature in the second catalyst layer arranged in the direction of flow is approximately at least 52 °C lower than the maximum temperature in the first catalyst layer. The inventive method enables the production of phthalic anhydride with high yields under conditions relevant to practice.