Preparation device and preparation method of cyanohydrin

Abstract

The invention provides a preparation device and a preparation method of cyanohydrin. The device comprises a feeder, a shell, an upper sealing head, a lower sealing head, reaction tubes and a liquid level meter, two ends of the shell are respectively connected with the upper sealing head and the lower sealing head, the feeder comprises a hydrocyanic acid feeding inlet, a first Venturi nozzle, a second Venturi nozzle, a catalyst feeding inlet and a static mixer; and a back plate is arranged in the shell, the reaction tube is filled with a filler, a position, close to the shell, of the upper sealing head is provided with a liquid distributor, and the lower sealing head is provided with a baffle plate. The preparation method comprises the following steps: material feeding, feeding of materials into the reactor, and material discharging, wherein the material feeding step is characterized in that a raw material 3-methylthiopropoanaldehyde is sent into a pipeline through the first Venturi nozzle, a raw material hydrocyanic acid is sent into the pipeline from the hydrocyanic acid feeding inlet, the raw materials enter the liquid distributor, go through the distribution holes of the liquid distributor and are sent into the corresponding reaction tubes, the reaction tubes are filled with the filler, and the obtained material is discharged after a reaction. The reaction yield is 99.99-99.998%.

Description

technical field [0001] The invention relates to the technical field of liquid-liquid phase reaction, and more specifically relates to a cyanohydrin preparation device and a preparation method thereof. Background technique [0002] 2-Hydroxy-4-methylthiobutyronitrile (cyanohydrin for short) is an important intermediate for the preparation of D,L-methionine or liquid methionine. At present, industrial production mainly uses gaseous or liquid hydrocyanic acid and 3-methylthiopropyl Aldehydes prepare cyanohydrins under the action of catalysts. For reaction efficiency and cost considerations, liquid hydrocyanic acid and 3-methylthiopropionaldehyde are generally used for liquid-liquid phase reaction. [0003] In industrial production, for liquid-liquid phase reactions, fixed bed, fluidized bed, tower reactor, trickle bed, slurry bed, pipe reactor and various traditional reactors are usually used for reaction. These reaction devices are used For the reaction, there will be incons...

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Problems solved by technology

In CN103664720, use hydrocyanic acid mixed gas to react to avoid the excessive use of hydrocyanic acid, but the reaction steps are complex and have both increased the difficulty of control in the reaction process, and at the same time, feeding the mixed gas has introduced a new radial temperature influence factor

[0007] The defect of prior art is: in the industrial production of 2-hydroxyl-4-methylthiobutyronitrile, the radial temperature of shell-and-tube reactor is difficult to control, and radial concentration is inhomogeneous, makes reaction between materials not thorough, and then Lead to low product yield and difficulties in continuous production

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