摘要:
A process for the long-term operation of a two-stage heterogeneously catalyzed gas phase partial oxidation of propene to acrylic acid, in which the temperature of the fixed catalyst beds is increased over the time and the gas phase partial oxidation is interrupted from time to time and an oxygen-containing gas mixture is conducted through the fixed catalyst beds at elevated temperature of the fixed catalyst beds.
摘要:
In a process for partially oxidizing acrolein to acrylic acid in the gas phase under heterogeneous catalysis, the starting reaction gas mixture is oxidized at an acrolein loading of ≦145 and ≧70 l (STP) of acrolein/l of fixed catalyst bed·h over a fixed catalyst bed which is accommodated in two successive reaction zones A, B, the highest temperature of the reaction gas mixture within reaction zone A being above the highest temperature of the reaction gas mixture within reaction zone B.
摘要:
A process for preparing (meth)acrolein and/or (meth)acrylic acid by heterogeneously catalyzed gas phase partial oxidation of an organic precursor compound over a fresh fixed catalyst bed, in which the process is started up at a reduced hourly space velocity of charging gas mixture on the fixed catalyst bed.
摘要:
A process for preparing (meth)acrolein and/or (meth)acrylic acid by heterogeneously catalyzed gas phase partial oxidation of an organic precursor compound over a fresh fixed catalyst bed, in which the process is started up at a reduced hourly space velocity of charging gas mixture on the fixed catalyst bed.
摘要:
In a process for heterogeneously catalyzed partial gas phase oxidation of propene to acrylic acid, the starting reaction gas mixture is oxidized at a propene loading of
摘要:
A process for starting-up a heterogeneously catalyzed partial gas phase oxidation of acrolein to acrylic acid or of methacrolein to methacrylic acid over a fixed catalyst bed disposed in a tube bundle reactor cooled by a heat exchange medium, wherein the temperature of the heat exchange medium is ≧290° C. and the temperature of that reactor plate surface which faces the reaction gas entry mixture and the temperature of the reaction gas entry mixture itself are ≦285° C.
摘要:
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; such precursor bodies per se; annular unsupported catalysts having a specific pore structure; and a method of using such annular unsupported catalysts for the catalytic partial oxidative preparation in the gas phase of (meth)acrolein.
摘要:
A process for recharging the reaction tubes of a tube bundle reactor with a new fixed catalyst bed, in which a heterogeneously catalyzed partial gas phase oxidation of an organic compound had been performed beforehand in a preceding fixed catalyst bed comprising Mo-comprising multielement oxide active compositions to form a steam-comprising product gas mixture, in which, before the recharge, solid deposit which had been deposited on the tube inner walls and comprises molybdenum oxide and/or molybdenum oxide hydrate is brushed away with the aid of a brush.
摘要:
An annular unsupported catalyst for the heterogeneously catalyzed partial gas phase oxidation of propene to acrolein at a propene hourly space velocity on the fixed catalyst bed of ≧120 1 (STP)/1·h and a total CO2 and saturated hydrocarbon content of the starting reaction gas mixture of below 15 mol %, the catalysts of the fixed catalyst bed are the annular unsupported catalysts whose active composition is a multimetal oxide in which the molar Co/Fe ratio=from 2 to 4 and the molar Co/Mo ratio=from 0.3 to 0.7.
摘要:
A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide of stoichiometry [BiaZ1bOx]p[BicMo12FedZ2eZ3fZ4gZ5hZ6iOy]1, in which a finely divided oxide BiaZ1bOx and, formed from element sources, a finely divided mixture of stoichiometry BicMo12FedZ2eZ3fZ4gZ5hZ6i are mixed in a ratio of p:1, this mixture is used to form shaped bodies and these are treated thermally, where 0