Continuous ammonia neutralization process of 2-methyl-5-nitroimidazole nitration completion liquid

Abstract

The invention discloses a continuous ammonia neutralization process of 2-methyl-5-nitroimidazole nitration completion liquid. The method comprises the following steps of: respectively conveying nitration reaction completion liquid diluted by water and ammonia water solution for neutralization to a T-shaped mixer by a steady flow conveying metering pump, and carrying out instantaneous mixing and instantaneous neutralization reaction, wherein the flow ratio of the nitration reaction completion liquid to the ammonia water solution for neutralization is subjected to linkage closed-loop regulation through the PH value of the mixed feed liquid in the crystallization kettle; after mixing is completed, entering the crystallization kettle for crystallization; and then, carrying out separation, washing and drying to obtain a finished product. The method has the advantages that the continuous ammonia neutralization of the nitration reaction completion liquid of the 2-methyl-5-nitroimidazole is realized, and the production efficiency is greatly improved; after the neutralized and washed product is dried, the appearance is whiter, and the quality is better; meanwhile, the yield of the product 2-methyl-5-nitroimidazole in the neutralization process is increased by 99.8% or above; and compared with the traditional intermittent neutralization process, the water consumption can be saved by more than 30%.

Description

technical field

[0001] The invention relates to a continuous ammonia neutralization process of 2-methyl-5 nitroimidazole nitration completion liquid, which belongs to the technical field of micro-reaction. Background technique

[0002] After the nitration reaction of 2-methyl-5 nitroimidazole is completed, it is necessary to neutralize the nitration reaction completed liquid with ammonia water to a pH value of 3 to 5, after neutralization, 2-methyl-5 nitroimidazole crystallizes out from the liquid phase, Thereby realize the separation of finished product 2-methyl-5 nitroimidazole. However, whether the current ammonia neutralization process is a traditional tank-type nitration process or a micro-reaction nitration process, the ammonia water neutralization process is to add ammonia water dropwise into the tank containing the nitration reaction completion liquid diluted with water under stirring conditions. This process is a batch operation process.

[0003] Practice has foun...

Examples

Embodiment 1

[0031] Embodiment 1: a kind of continuous ammonia neutralization process of 2-methyl-5 nitroimidazole nitration reaction completion liquid, it comprises the following steps: 2-methyl-5 nitroimidazole nitration reaction completion liquid is loaded into nitration reaction completion liquid In the tank 1, put the ammonia solution with a concentration of 27% into the ammonia solution tank 2, turn on the steady flow metering pump 4 of the nitrification completed liquid, set the flow rate of the nitrification completed liquid flowmeter 6 to 17300g / min, and turn on the steady flow metering of the ammonia water Pump 3, adjust the flow rate of ammonia water through the ammonia water flow meter 5 so that the pH value of the material entering the crystallization kettle 8 from the outlet of the T-type mixer 7 is 3, and open the interlocking adjustment of the pH value of the mixed liquid and the ratio of the flow rate of ammonia water to the flow rate of the nitrification completed liquid, a...

Embodiment 2

[0032] Embodiment 2: a kind of continuous ammonia neutralization process of 2-methyl-5 nitroimidazole nitration reaction completion liquid, it comprises the following steps: 2-methyl-5 nitroimidazole nitration reaction completion liquid is loaded into nitration reaction completion liquid In the tank 1, put the ammonia solution with a concentration of 31% into the ammonia solution tank 2, turn on the steady flow metering pump 4 of the nitrification completed liquid, set the flow rate of the nitrification completed liquid flow meter 6 to 17300g / min, and turn on the steady flow metering of the ammonia water Pump 3, adjust the flow rate of ammonia water through the ammonia water flow meter 5 so that the pH value of the material entering the crystallization kettle 8 from the outlet of the T-type mixer 7 is 5, and open the interlocking adjustment of the pH value of the mixed liquid and the ratio of the flow rate of ammonia water to the flow rate of the nitrification completed liquid, ...

Embodiment 3

[0033] Embodiment 3: a kind of continuous ammonia neutralization process of 2-methyl-5 nitroimidazole nitration completion liquid, it comprises the following steps: 2-methyl-5 nitroimidazole nitration reaction completion liquid is loaded into nitration reaction completion liquid In the tank 1, put the ammonia solution with a concentration of 29% into the ammonia solution tank 2, turn on the steady flow metering pump 4 of the nitrification completed liquid, set the flow rate of the nitrification completed liquid flow meter 6 to 17300g / min, and turn on the steady flow metering of the ammonia water Pump 3, adjust the flow rate of ammonia water through the ammonia water flow meter 5 so that the pH value of the material entering the crystallization kettle 8 from the outlet of the T-type mixer 7 is 4, and open the chain adjustment of the pH value of the mixed liquid and the ratio of the flow rate of ammonia water to the flow rate of the nitrification completed liquid, and always maint...

technical field

[0001] The invention relates to a continuous ammonia neutralization process of 2-methyl-5 nitroimidazole nitration completion liquid, which belongs to the technical field of micro-reaction. Background technique

[0002] After the nitration reaction of 2-methyl-5 nitroimidazole is completed, it is necessary to neutralize the nitration reaction completed liquid with ammonia water to a pH value of 3 to 5, after neutralization, 2-methyl-5 nitroimidazole crystallizes out from the liquid phase, Thereby realize the separation of finished product 2-methyl-5 nitroimidazole. However, whether the current ammonia neutralization process is a traditional tank-type nitration process or a micro-reaction nitration process, the ammonia water neutralization process is to add ammonia water dropwise into the tank containing the nitration reaction completion liquid diluted with water under stirring conditions. This process is a batch operation process.

[0003] Practice has foun...

Examples

Embodiment 1

[0031] Embodiment 1: a kind of continuous ammonia neutralization process of 2-methyl-5 nitroimidazole nitration reaction completion liquid, it comprises the following steps: 2-methyl-5 nitroimidazole nitration reaction completion liquid is loaded into nitration reaction completion liquid In the tank 1, put the ammonia solution with a concentration of 27% into the ammonia solution tank 2, turn on the steady flow metering pump 4 of the nitrification completed liquid, set the flow rate of the nitrification completed liquid flowmeter 6 to 17300g / min, and turn on the steady flow metering of the ammonia water Pump 3, adjust the flow rate of ammonia water through the ammonia water flow meter 5 so that the pH value of the material entering the crystallization kettle 8 from the outlet of the T-type mixer 7 is 3, and open the interlocking adjustment of the pH value of the mixed liquid and the ratio of the flow rate of ammonia water to the flow rate of the nitrification completed liquid, a...

Embodiment 2

[0032] Embodiment 2: a kind of continuous ammonia neutralization process of 2-methyl-5 nitroimidazole nitration reaction completion liquid, it comprises the following steps: 2-methyl-5 nitroimidazole nitration reaction completion liquid is loaded into nitration reaction completion liquid In the tank 1, put the ammonia solution with a concentration of 31% into the ammonia solution tank 2, turn on the steady flow metering pump 4 of the nitrification completed liquid, set the flow rate of the nitrification completed liquid flow meter 6 to 17300g / min, and turn on the steady flow metering of the ammonia water Pump 3, adjust the flow rate of ammonia water through the ammonia water flow meter 5 so that the pH value of the material entering the crystallization kettle 8 from the outlet of the T-type mixer 7 is 5, and open the interlocking adjustment of the pH value of the mixed liquid and the ratio of the flow rate of ammonia water to the flow rate of the nitrification completed liquid, ...

Embodiment 3

[0033] Embodiment 3: a kind of continuous ammonia neutralization process of 2-methyl-5 nitroimidazole nitration completion liquid, it comprises the following steps: 2-methyl-5 nitroimidazole nitration reaction completion liquid is loaded into nitration reaction completion liquid In the tank 1, put the ammonia solution with a concentration of 29% into the ammonia solution tank 2, turn on the steady flow metering pump 4 of the nitrification completed liquid, set the flow rate of the nitrification completed liquid flow meter 6 to 17300g / min, and turn on the steady flow metering of the ammonia water Pump 3, adjust the flow rate of ammonia water through the ammonia water flow meter 5 so that the pH value of the material entering the crystallization kettle 8 from the outlet of the T-type mixer 7 is 4, and open the chain adjustment of the pH value of the mixed liquid and the ratio of the flow rate of ammonia water to the flow rate of the nitrification completed liquid, and always maint...

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