Patent DE-102005049699-A1 (DE)
Title: Preparation of acrolein/acrylic acid comprises supplying gas mixture stream A to zone A, supplying propane gas stream to obtain product gas mixture; dividing product stream A into two component streams; feeding a stream to zone B
Inventor: KLANNER CATHARINA
IPC: C07C47/22
Filed: 2005-10-14
Abstract: Preparation of acrolein/acrylic acid from propane comprises supplying reaction gas mixture input stream A to a reaction zone A; supplying dehydrogenated propane gas stream to obtain a product gas mixture; removing the product mixture stream A; dividing the product gas mixture stream A into component streams (I) and (II); feeding the component stream (II) in a second reaction zone B into an oxidative reactor, in which propylene in stream (II) is oxidized to form a product gas mixture B containing e.g. acrolein/acrylic acid as final product and separating the final product. Preparation of acrolein and/or acrylic acid from propane comprises supplying a reaction gas mixture input stream A (which is produced by merging at least four different gaseous initial streams 1, 2, 3 and 4) to the inlet of the first reaction zone A by at least a catalyst bed; optionally further supplying partially, heterogeneously catalyzed dehydrogenated propane gas stream to the mixture to obtain a product gas mixture containing propane and propylene; removing the obtained product gas mixture stream A from the first reaction zone A by discharge opening; dividing the product gas mixture stream A into two component streams (I) and (II) with identical composition, where the component stream (I) is fed back as gaseous initial stream 1 into the first reaction zone A in a first gas cycle operation and the component stream (II) is optionally led into the first separation zone A, to separate partial or large quantity of different propane and propylene components and to produce a residual product gas mixture stream A1 containing propane and propylene; feeding the component stream (II) or the product gas mixture in a second reaction zone B into at least an oxidative reactor, in which the propylene contained in the component stream (II) or in the product gas mixture stream A1 is subjected to selective heterogeneously catalyzed partial gaseous phase oxidation with molecular oxygen to form a product gas mixture B containing acrolein and/or acrylic acid as final product, optionally unconverted propane and propylene, and surplus molecular oxygen; removing the product gas mixture stream B from the reaction zone B; separating the final product, where the residual gas containing unconverted propane and propylene, and molecular oxygen is fed back as gaseous initial stream 2 in a second gas cycle operation into the reaction zone A (when the gaseous initial streams 2, 3 and 4 and optionally a gaseous stream different from the 1 are merged to a single propelled jet gaseous mixture stream); and subsequently operating the mixture with gaseous propelled jet mixture stream as propelled jet of a jet pump, which comprises a jet nozzle, a mixing path, a diffuser and a suction intake socket; where the direction of the propulsion of the propelled jet by the jet nozzle over a mixing path and the diffuser, points towards the inlet of the first reaction zone A and the suction effect of the suction intake socket, points towards the direction of the discharge opening of the first reaction zone A leading to the product gas mixture stream A and the component stream (I) is sucked through the negative pressure produced in the suction intake socket along with the splitting up of the product gas mixture A into the two component stream, and is transported with simultaneous mixing of propelled jet by the mixing path over the diffuser and the obtained reaction gas mixture input stream A is left into the inlet of the first reaction zone A; the gaseous initial streams 1, 2 and 3 is a propane, the gaseous initial stream 4 is a molecular hydrogen and the gaseous initial stream 3 is a fresh propane; the first gaseous initial stream 2 and 3 and optionally stream 1 and stream 4 are combined in an arbitrary sequence to a single gaseous mixture stream and stream 4 is added to the gaseous initial mixture stream under the formation of the gaseous propelled jet mixture stream.