Continuous crystallization process for preparing nitroguanidine through nitric acid method

A nitroguanidine, nitric acid method technology, applied in the preparation of organic compounds, chemical instruments and methods, organic chemistry and other directions, can solve the problems of reducing product yield, energy waste, complicated process routes, etc., to reduce waste water discharge, The effect of improving product yield and reducing reaction conditions

Inactive Publication Date: 2015-08-26
XIAN MODERN CHEM RES INST
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  • Abstract
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  • Application Information

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Problems solved by technology

[0003] The current production methods of nitroguanidine mainly include the nitric-sulfur mixed acid method and the nitric acid method: every ton of nitroguanidine produced by the nitric-sulfur mixed acid method produces about 23 tons of 16% dilute sulfuric acid. Crystallization and purification, the process not only produces a large amount of waste water containing nitroguanidine, which causes environmental pollution, but also causes waste of energy and complicates the process
Chinese patent (publication number CN103183620A) has announced a kind of method for synthesizing nitroguanidine in Corning microreactor, is the representative that nitric sulfur mixed acid method prepares nitroguanidine, and this method is dissolved in sulfuric acid solution earlier with guanidine sulfate, and then Nitrate with concentrated nitric acid in a microreactor, the molar ratio of sulfuric acid to nitric acid is 1:1, and 1 mol of nitroguanidine is produced to generate 1 mol of low-concentration waste sulfuric acid that is difficult to recycle; the crystallized product is recrystallized three times In order to meet the qualification, the product yield is reduced and a large amount of waste water is generated
Chinese patent (publication number CN102827038B) discloses a method for preparing nitroguanidine by nitric acid method. The process does not generate waste sulfuric acid. One-time crystallization produces nitroguanidine that meets the requirements of the national military standard, but the reaction process is prepared by a one-pot method. The product yield is low, and the crystallization process is discontinuous operation, and the process route is cumbersome. In the process of product post-treatment, washing 1 ton of nitroguanidine product produces about 10 tons of waste water, and introduces a new impurity Na 2 CO 3

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  • Continuous crystallization process for preparing nitroguanidine through nitric acid method

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Effect test

Embodiment 1

[0024] The present embodiment carries out as follows:

[0025] (1) Turn on the constant temperature water tank 3 and the refrigeration device 9, and set the temperature to 43°C and -3°C respectively;

[0026] (2) close emptying valve 8, be that the dilute nitric acid 200ml of 40% is joined in the continuous crystallizer 6 with mass concentration, open agitator 5, rotating speed is controlled at 800r / min;

[0027] (3) will dissolve 90g guanidine nitrate, 240ml of nitric acid solution of mass concentration 70%, squeeze in the microtube reactor 2 through metering pump 1, the flow rate of regulating and controlling metering pump is 20ml / min, the stop of liquid in the microtube reactor The time is 150s, drips in the continuous crystallizer 6 afterwards, crystallizes out white nitroguanidine crystal;

[0028] (4) Open the overflow valve 10 and the water inlet valve 4. Control tap water to flow into the continuous crystallizer 6 at a flow rate of 10ml / min, and the mixed suspension ...

Embodiment 2

[0032] The present embodiment carries out as follows:

[0033] (1) Turn on the constant temperature water tank 3 and the refrigeration device 9, and set the temperature to 45°C and -3°C respectively;

[0034] (2) close emptying valve 8, be that 30% dilute nitric acid 200ml joins in the continuous crystallizer 6 with mass concentration, open agitator 5, and the rotating speed is controlled at 800r / min;

[0035] (3) will dissolve 90g guanidine nitrate, 240ml of nitric acid solution of mass concentration 68%, squeeze in the microtube reactor 2 through metering pump 1, the flow velocity of regulating and controlling metering pump is 20ml / min, the stay of liquid in the microtube reactor The time is 150s, drips in the continuous crystallizer 6 afterwards, crystallizes out white nitroguanidine crystal;

[0036] (4) Open the overflow valve 10 and the water inlet valve 4. Control tap water to flow into the continuous crystallizer 6 at a flow rate of 10ml / min, and the mixed suspension...

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Abstract

The invention relates to a continuous crystallization process for preparing nitroguanidine through a nitric acid method. The process is applied to continuous crystallization for preparing single-compound explosive nitroguanidine and belongs to the technical field of preparation processes of explosives and powder. According to the process disclosed by the invention, the nitroguanidine is dissolved in a nitric acid solution, the synthetic process is optimized by virtue of a micro-tube reactor, the requirement of the reaction system on the nitric acid concentration is reduced, and the product yield is improved. A continuous crystallizer and a filter are arranged behind the micro-tube reactor, the continuous crystallization and filtration process is established, the manual operation is reduced, and the production efficiency of the product is improved; and moreover, with the adoption of ultrasonic oscillating and washing, the washing frequency is reduced, and wastewater emission is reduced. The process disclosed by the invention has the advantages of simplicity, high continuity, high product yield, small wastewater emission amount and the like and is particularly suitable for continuous crystallization for preparing single-compound explosive nitroguanidine.

Description

technical field [0001] The invention relates to a process for preparing nitroguanidine, in particular to a process for preparing nitroguanidine by continuous crystallization with nitric acid method. Specifically, the present invention is an improvement to the process for preparing nitroguanidine with nitric acid method. Background technique [0002] Nitroguanidine is an energetic material widely used in propellants, propellants, and explosives. At the same time, it is also widely used as a gas generating agent component in the air bag system of motor vehicles and aircraft. Derivatives of nitroguanidine are also widely used in various industries, such as medicine and pesticides. [0003] The current production methods of nitroguanidine mainly include the nitric-sulfur mixed acid method and the nitric acid method: every ton of nitroguanidine produced by the nitric-sulfur mixed acid method produces about 23 tons of 16% dilute sulfuric acid. The process of crystallization and ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C279/34C07C277/08
Inventor 徐其鹏陈松罗志龙邹高兴杨毅雷全虎陈基王晓东康超李萌张亮李菲
Owner XIAN MODERN CHEM RES INST
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