Abstract: A process for catalytically generating organic substances by partial oxidation of an organic feedstock in the presence of molecular oxygen at temperatures in the range from 200 to 500° C. in at least one cooling-tube reactor, wherein 40 to 100 wt-% of the total amount of catalyst is disposed as a coating on the outside of the cooling tubes.

Abstract: Process for generating a homogeneous gas mixture of o-xylene and air for the production of phthalic anhydride wherein o-xylene is completely evaporated in the absence of oxygen, superheated and then mixed with air and supplied to a phthalic anhydride reactor.

Abstract: To improve the columns used so far for producing phthalic anhydride, and to make them less expensive and easier to install, it is proposed that in the column for concentrating phthalic anhydride two distillation stages are arranged, wherein the removal of the low-boiling components of the crude phthalic anhydride by distillation is effected in the first distillation stage (2) and the separation of the high-boiling components from the pure phthalic anhydride is effected in the second distillation stage (3), both distillation stages being arranged side by side and being separated from each other by a vertical wall (4), and that the bottom (7) of the first distillation stage (2) is connected with the bottom (10) of the second distillation stage (3).

Abstract: The process is performed in the gas phase in the presence of molecular oxygen at temperatures in the range from 200 to 500° C. in at least one reactor, which constitutes a cooling-tube reactor and contains a catalyst. Cooling liquid flows through the cooling tubes of the reactor, and from the reactor a gaseous product mixture is withdrawn. 40 to 100 wt-% of the total amount of catalyst of the cooling-tube reactor are disposed as coating on the outside of the cooling tubes, wherein the feed mixture containing the feedstock and the molecular oxygen gets in contact with the catalyst layers. Preferably, at least half the cooling tubes constitute ribbed tubes with ribs protruding on the outside, the ribs being at least partly coated with catalyst.

Abstract: To improve the columns used so far for producing phthalic anhydride, and to make them less expensive and easier to install, it is proposed that in the column for concentrating phthalic anhydride two distillation stages are arranged, wherein the removal of the low-boiling components of the crude phthalic anhydride by distillation is effected in the first distillation stage (2) and the separation of the high-boiling components from the pure phthalic anhydride is effected in the second distillation stage (3), both distillation stages being arranged side by side and being separated from each other by a vertical wall (4), and that the bottom (7) of the first distillation stage (2) is connected with the bottom (10) of the second distillation stage (3).

Abstract: Process for generating a homogeneous gas mixture of o-xylene and air for the production for the production of phthalic anhydride wherein o-xylene is completely evaporated in the absence of oxygen, superheated and then mixed with air and supplied to a phthalic anhydride reactor.