METHOD OF HETEROGENEOUS CATALITIC PARTIAL DIRECT OXIDATION OF PROPANE AND/OR ISO-BUTANE Russian patent published in 2009 - IPC C07C51/215 B01J27/57 C07C51/25 C07C57/05 

FIELD: chemistry.

SUBSTANCE: method is performed until at least one of such end products as acrylic acid, methacrylic acid are prepared that is ensured with supplying propane and/or iso-butane, molecular oxygen and a base mixture of reaction gas, containing at least one inert diluent gas at input pressure P¹ at the stage of reaction being gas-impermeable with the exception of inlet for the base mixture of reaction gas, if required, other inlets for auxiliary gases, and also outlet for product gas mixture. At the specified stage of reaction, by supplying the base mixture of reaction gas at higher temperature propane and/or iso-butane are oxidised to at least one end product through the catalyst being in solid aggregate state and contained in the base mixture of reaction gas. Reaction gas mixture as containing at least one end product of product gas mixture is discharged from the reaction stage at outlet pressure P², and at the same pressure P² delivered to the processing stage being gas-impermeable with the exception of inlet for product gas mixture, if required, other inlets for auxiliary gases, and also outlet for residual product gas mixture. At the processing stage, the end product is coarsely separated from product gas mixture of the reaction stage thus forming the liquid phase, while residual product gas mixture containing propane and/or iso-butane, as well as, if required, propene and/or iso-butene, is delivered from the processing stage at inlet pressure P³, with P³ being less than P¹. Propane or iso-butane from the residual product gas mixture is delivered back to the reaction stage where P¹ is specified so that P³ is 1.5 bar or more. The residual product gas mixture is divided on two parts of the same composition with one part discharged. The other part is delivered as circulating gas and supplied back to the reaction stage as a component of the base mixture of reaction gas compressed to inlet pressure P¹. The problem of heterogeneous catalytic partial direct oxidation consists in ensuring maxially higher conversion of propane and/or iso-butane at lowest temperatures and one-stage passage of reaction gas mixture through the reaction stage with simultaneous highest selectivity of end product and lowest energy consumption.

EFFECT: method improvement.

32 cl, 1 tbl, 1 ex, 3 dwg