Abstract: A process for mixing a liquid or mixture of a liquid and a fine solid present in a vessel, in which the vessel is supplied with the same liquid or the same mixture as a motive jet of a jet nozzle which is present in the vessel and has a motive jet and a momentum exchange chamber, the suction region between motive nozzle and momentum exchange chamber being provided with a sheath which has a suction orifice below the central jet leading from the motive nozzle into the momentum exchange chamber.

Abstract: A process for rectificatively separating a liquid which comprises acrylic acid, methacrylic acid or a mixture thereof, and additionally comprises low molecular weight aldehydes and acetone.

Abstract: A chimney tray for a column for the thermal treatment of a liquid, comprising an upper tray and a lower tray which are spaced apart from one another, arranged substantially horizontally in the column, comprising chimneys, and also comprising drawing of the liquid via a drainage spout arranged at the edge of the chimney tray, wherein the upper tray and the lower tray have a minimum separation from one another of from 10 to 500 mm and, between the upper tray and the lower tray, a gas having a thermal conductivity of less than 0.5 watt/m/K has been incorporated.

Abstract: A process for preparing acrolein or acrylic acid or a mixture thereof by heterogeneously catalyzed partial gas oxidation of propylene, in which the starting reaction gas mixture has the following contents: from 6 to 9% by volume of propylene, from 8 to 18% by volume of molecular oxygen, from 6 to 30% by volume of propane and from 32 to 72% by volume of molecular nitrogen.

Abstract: A process for the long-term operation of a heterogeneously catalyzed gas phase partial oxidation of at least one organic compound over a catalyst bed, in which, in order to counteract the deactivation of the catalyst bed, the working pressure in the gas phase is increased during the operating time of the catalyst bed.

Abstract: A thermal separating process for removing a stream containing enriched (meth)acrylic monomers from a mixture containing (meth)acrylic monomers, in which the liquid phases retained in the separating space at high temperature and high (meth)acrylic monomer content are minimized.

Abstract: A process for preparing annular unsupported catalysts by thermally treating annular shaped unsupported catalyst precursor bodies, wherein the side crushing strength of the annular shaped unsupported catalyst precursor bodies is ?12 N and ?23 N. In addition, resulting annular unsupported catalysts having a specific pore structure and also the use of such annular unsupported catalysts for the catalytic partial oxidative preparation in the gas phase of (meth)acrolein.