Process method and method for regenerating methyl nitrite in production of dimethyl oxalate

Abstract

The invention belongs to the technical field of the production of dimethyl oxalate, and particularly relates to a process method and a device for regenerating methyl nitrite in the production of the dimethyl oxalate. In the method, the utilization rate of nitric oxide in the regenerative process is improved, and the using amount of methanol is reduced. The device comprises a rotary filler bed, wherein a gas inlet of the rotary filler bed is connected with sources of nitrogen, oxygen and nitric oxide respectively, a liquid inlet is connected with a methanol storage tank, a liquid outlet is connected with an inlet of a methanol-water mixture storage tank, and a gas outlet is connected with a condenser I. The process method comprises the following steps of: opening the rotary filler bed, so that the nitric oxide, the nitrogen and the oxygen are contacted and reacted with absolute methanol in the rotary filler bed to form a gas phase and a liquid phase; and discharging the gas phase, condensing, and allowing the liquid phase to flow into the methanol-water mixture storage tank. The process method has the advantages that: the process reaction efficiency is high; all NO is used efficiently; and the equipment has a compact structure and small volume and requires a small investment. The equipment has the advantages of making operation easy, along with simple structure, small energy consumption, simple flow, convenience for starting and stopping and the like.

Description

technical field [0001] The invention belongs to the technical field of dimethyl oxalate production, and in particular relates to a process and device for regeneration of methyl nitrite in the production process of dimethyl oxalate, in particular to the recycling of nitric oxide. Background technique [0002] Dimethyl oxalate is an important organic chemical raw material and intermediate. It is widely used in the fine chemical industry to prepare various dyes, medicines, and pesticides. It is also an important solvent and extraction agent. Dimethyl oxalate is hydrolyzed to produce oxalic acid, which can be used to produce high value-added special chemicals for electronic information and national defense atomic energy industries. Organic chemical products such as ammonium oxalate can be obtained by ammoniation. Ethylene glycol is produced by hydrogenation of dimethyl oxalate. Ethylene glycol is also an important chemical raw material. It is widely used in the production of synt...

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Problems solved by technology

[0026] And at present, the above-mentioned regeneration reaction is usually carried out in a bubble column and a packed column, and there are following problems in using these equipment: due to the long residence time and uneven mixing of the fluid in these equipment, the N 2 o 4 The generation of by-products such as nitric acid and formaldehyde leads to a low utilization rate of NO, so that the system needs to add a certain amount of NO in the coupling reaction, which directly affects the ratio relationship between the materials in the coupling and regeneration reactions. , and the mass transfer and reaction efficiency in traditional tower equipment is low, which requires a large amount of methanol, resulting in problems such as increased side reactions and large rectification load

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