Patent RU-2429218-C2 (RU)
Title: Method of producing acrolein, acrylic acid or mixture thereof from propane
Inventor: KLANNER KATARINA
IPC: C07C51/215
Filed: 2006-10-05
Granted: 2011-09-20
Abstract: FIELD: chemistry. 
     SUBSTANCE: according to method A) an input stream of the reaction gaseous mixture A is fed into the input of the first reaction zone A, where the input stream is obtained by merging at least four different gaseous initial streams 1, 2, 3 and 4, where the gaseous initial streams 1 and 2 contain propane, gaseous initial stream 4 is molecular hydrogen and gaseous initial stream 3 is fresh propane, the input stream of the reaction gaseous mixture A is passed at least through one catalyst layer of the first reaction zone A on which, if needed, when feeding other gaseous streams, as a result of heterogeneous catalytic partial dehydrogenation of propane, a stream of products of gaseous mixture A forms, which contains propane and propylene, the stream of products of gaseous mixture A comes out of the first reaction zone A through the corresponding outlet, while splitting said stream into two partial streams 1 and 2 of products of the gaseous mixture A with identical composition, and the partial stream 1 of products of the gaseous mixture A is returned to the first reaction zone A as the gaseous initial stream 1, the partial stream 2 of products of the gaseous mixture A, if needed, is directed to the first separation zone A, in which a portion or more of components contained therein, which are different from propane and propylene, are separated, as a result of which a stream of products of gaseous mixture A' which contains propane and propylene, B) partial stream 2 of products of the gaseous mixture A or a stream of products of gaseous mixture A' is used in a second reaction zone B for supplying at least one oxidation reactor, in which propylene contained in the partial stream 2 of products of gaseous mixture A or in the stream of products of gaseous mixture A' undergoes selective heterogeneously catalysed partial gas-phase oxidation with molecular oxygen to obtain a stream of products of a gaseous mixture B, which contains acrolein, acrylic acid or mixture thereof as the desired product, unconverted propane and, if needed, unconverted propylene, as well as molecular oxygen, the stream of products of gaseous mixture B comes out of reaction zone B, the desired product contained in separation zone B is separated in said separation zone B and at least a portion of residual gas formed after separation and containing unconverted propane, molecular oxygen and, if needed, unconverted propylene, is returned to reaction zone A as gaseous initial stream 2. Gaseous initial streams 2, 3 and 4 as well as, if needed, additional gaseous initial streams different from the gaseous initial stream 1, are merged into a gaseous stream of the working mixture, after which, using this gaseous stream of the working mixture as the working stream, a jet pump is activated, said pump having a nozzle, a mixing section, a diffuser and a suction inlet. Movement of the working stream which is throttled through the nozzle, the mixing section and the diffuser to the input of the first reaction zone A, as well as the suction effect of the suction inlet takes place in the direction of outlet of the stream of products of gaseous mixture A from the first reaction zone A. The pressure drop created in the suction nozzle with splitting of the stream of products of the gaseous mixture A into two partial streams 1 and 2 results in suction of the partial stream 1 of products of the gaseous mixture A, its movement through the diffuser with simultaneous mixture with the working stream on the mixing section and inlet of the formed reaction stream of gaseous mixture A at its inlet point into the first reaction zone A, characterised by that a gaseous initial mixed stream is formed first by merging in random sequence gaseous initial streams 2 and 3, as well as, if needed, additional gaseous initial streams different from gaseous initial streams 1 and 4, and only after that the gaseous initial stream 4 is added to the formed gaseous initial mixed stream to obtain a gaseous mixed working stream. 
     EFFECT: used of present method reduces heat loss and prevents a drop in degree of dehydrogenation when producing acrolein, acrylic acid or mixture thereof from propane. 
     7 cl, 4 ex, 4 dwg