Process and device for producing maleic anhydride by n-butane selective oxidation

Abstract

The invention belongs to the field of maleic anhydride production, and particularly relates to a process and a device for producing maleic anhydride by n-butane selective oxidation. The n-butane is vaporized, heated, and mixed with an auxiliary sequentially, and then enters an air / n-butane mixer; the air is mixed with humidified steam in a humidification mixer, and heated by an air heater and thenenters the air / n-butane mixer to be mixed with the mixture of the n-butane and the auxiliary; the mixed material enters a reactor to react, and a produced gas is discharged to a next unit; the reactor is internally provided with a plurality of tubes, the tubes are filled with catalysts, and the shell pass outside each tube is divided by clapboards into a plurality of heat taking chambers which are not communicated with each other up and down; the inlet of each heat taking chamber is connected with a heat taking medium inlet tube, and the outlet of each heat taking chamber is connected with aheat taking medium outlet tube; a flow control valve is arranged between each heat taking chamber and the corresponding heat taking medium inlet pipe. The process and device provided by the inventioncan effectively prevent the local overheating of the reactor, improve the activity of the catalysts, and prolong the service life of the catalysts.

Description

technical field [0001] The invention belongs to the field of maleic anhydride production, in particular to a process and device for producing maleic anhydride through selective oxidation of n-butane. Background technique [0002] Maleic anhydride, maleic anhydride for short, also known as maleic anhydride, is an important organic chemical raw material, widely used in petrochemical, food processing, medicine, building materials and other industries. According to the raw material route, the production method of maleic anhydride can be divided into benzene oxidation method and n-butane oxidation method. The n-butane method has the advantages of cheap raw materials, relatively light pollution, high utilization rate of carbon atoms and low production cost of maleic anhydride. trend. [0003] The core of the maleic anhydride production technology is the gas-solid phase catalytic oxidation reaction of n-butane and air in a reactor filled with a vanadium phosphorus oxygen catalyst...

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Problems solved by technology

Patent CN201110236413.6 proposes a maleic anhydride production reaction temperature adjustment control device and method. The core technology of this patent is to use a shell / tube reactor, and a molten potassium nitrate and nitrous acid are used in the shell side of the reactor The sodium mixture is reciprocated by the molten salt pump as a heat transfer cooling medium. The disadvantage of this patent is that while the molten salt reduces the temperature of the hot spot, it will also reduce the temperature of other parts of the bed, resulting in the conversion of n-butane and the yield of maleic anhydride. rate reduction

The patent USP4855459 adopts the method of diluting and filling inert silicon-aluminum balls and catalysts, and achieves the purpose of reducing the temperature of the hot spot of the reaction by diluting and filling the hot spot generation part of the reaction tube. The disadvantage of the above patent is that the addition of inert materials reduces the temperature of the reactor. effective volume, which also reduces productivity

Patent CN201510806387.4 discloses a method for reducing reaction hot spots in the reactor. The core technology of this patent is to use three series-connected vanadium-phosphorus-oxygen catalyst beds. The average valence state of vanadium in the three series-connected catalyst beds is sequentially The trend of first high, then low, and then rising. The disadvantage of this patent is that it has high requirements for catalyst preparation and activation process and poor implementability.

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