Process for the preparation of hydrazine sulfate and apparatus therefor

Abstract

The present application relates to the technical field of synthetic chemistry, more particularly, to a preparation method and device of hydrazine sulfate. The present application is aimed at solving the problems of low preparation efficiency and poor safety of hydrazine sulfate. The first object of the present application is to provide a preparation method of hydrazine sulfate. Hydrazine hydrate and concentrated sulfuric acid are first input into a micro-mixer under the conduction of a fluid conduction medium, then input into a spiral tube reactor connected with the micro-mixer for stabilization and reaction, and then cooled to obtain an intermediate product liquid. The intermediate product liquid is post-treated to obtain hydrazine sulfate. The second object of the present application is to provide a device for preparing hydrazine sulfate, comprising a micro-mixer, a spiral tube reactor and a cooling tube connected in sequence. The input end of the micro-mixer is connected with a first feeding pipe, a second feeding pipe and a third feeding pipe for feeding into the micro-mixer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of synthetic chemistry, more particularly, to a preparation method of hydrazine sulfate and a preparation device thereof. BACKGROUND

[0002] Hydrazine sulfate is an important organic compound, which is widely used in the fields of medicine, pesticide, dye, synthetic resin, etc. At present, the equipment for preparing hydrazine sulfate is mainly a kettle reactor, i.e. hydrazine hydrate and concentrated sulfuric acid are subjected to acid-base reaction under the conditions of heating and stirring to generate hydrazine sulfate and water, as shown in the following formula:

[0003] N2H 4· H20+H2S04→N2H 4· H2S04+H20

[0004] This method has the following disadvantages: there is obvious heat release phenomenon in the reaction process, which leads to difficult control of the reaction temperature, easy reaction out of control or product decomposition, and affects the quality and yield of the product; the contact of reactants is not sufficient, which requires constant stirring, leading to long reaction time, low product purity, uneven product distribution, and increasing the difficulty and cost of post-processing; the contact area of the reactor with the outside world is small, leading to low heat transfer efficiency, high energy consumption, poor safety, and easy occurrence of overflow, leakage, corrosion and other accidents, which cause harm to personnel and equipment.

[0005] As can be seen, the method for preparing hydrazine sulfate by using a kettle reactor has the problems of low efficiency, poor quality, high cost, poor safety, etc. In addition, since the reaction generates a precipitate, even if the traditional tubular reaction process is directly used, there will be the problems of blockage and insufficient mixing, leading to insufficient uniformity.

[0006] Therefore, it is urgent to find a new preparation method to improve the efficiency and quality of the preparation of hydrazine sulfate, and reduce energy consumption and risk. SUMMARY

[0007] The present application aims to overcome at least one of the above-mentioned defects of the prior art, and provides a preparation method of hydrazine sulfate and a device for preparing hydrazine sulfate, which are used to solve the problems of low efficiency and poor safety in the preparation of hydrazine sulfate.

[0008] The first object of the present application is to provide a preparation method of hydrazine sulfate, comprising the following steps:

[0009] S1. hydrazine hydrate and concentrated sulfuric acid are first input into a micro-mixer for mixing under the conduction of a fluid conduction medium, and then input into a spiral tube reactor in communication with the micro-mixer for stable and reaction, and then subjected to cooling treatment to obtain an intermediate product liquid;

[0010] S2. The intermediate product liquid is centrifuged to collect crystals, and the crystals are sequentially washed and dried to obtain hydrazine sulfate.

[0011] The present application firstly realizes rapid and uniform mixing of hydrazine hydrate and sulfuric acid through a micro-mixer, improves the selectivity and conversion rate of the reaction, introduces a fluid conducting medium, and improves the flow efficiency of hydrazine hydrate and concentrated sulfuric acid in the whole reaction process based on the conducting effect of the fluid conducting medium, avoids the blockage caused by the slow operation of the precipitate generated in the micro-mixer, and then further mixes and reacts hydrazine hydrate and sulfuric acid through a spiral pipe reactor to improve the uniformity and stability of the reaction, realize continuous production of the reaction, and improve the quality, consistency and preparation efficiency of the product. The present application realizes the continuous reaction of hydrazine hydrate and concentrated sulfuric acid in a plug flow mode based on the organic combination of the fluid conducting medium, the micro-mixer and the spiral pipe reactor, reduces the back mixing phenomenon, improves the selectivity and conversion rate of the reaction, realizes the heat exchange efficiency of the reaction, avoids the occurrence of side reactions, and effectively solves the problems of low preparation efficiency and poor safety of hydrazine sulfate.

[0012] Further, the temperature of hydrazine hydrate is adjusted to 20-80℃, preferably 20℃, before being input into the micro-mixer.

[0013] Further, the temperature of concentrated sulfuric acid is adjusted to 20-80℃, preferably 20-60℃, before being input into the micro-mixer.

[0014] Further, the molar ratio of the feeding amount of hydrazine hydrate to concentrated sulfuric acid is 1:1-1:3.

[0015] Further, the flow rate of hydrazine hydrate introduced into the micro-mixer is 0.05-1L / min, preferably 0.05-0.3L / min.

[0016] Further, the flow rate of concentrated sulfuric acid introduced into the micro-mixer is 0.05-1L / min, preferably 0.05-0.3L / min.

[0017] Further, the flow rate of the fluid conducting medium input into the micro-mixer is 1-3L / min, preferably 1-1.5L / min.

[0018] Further, the pressure of the fluid conducting medium input into the micro-mixer is 1-10atm.

[0019] Further, the fluid conducting medium is any one or a mixture of more than one of water, methanol, ethanol, air, nitrogen and oxygen.

[0020] Further, the reaction temperature in the micro-mixer is set to 40-80℃.

[0021] Further, the reaction temperature in the spiral pipe reactor is set to 40-80℃.

[0022] Further, the pressure in the spiral tube reactor is set to 1-10 atm.

[0023] Further, the cooling temperature is set to 0-25℃ during the cooling process.

[0024] The second object of the present application is to provide a device for preparing hydrazine sulfate, which is suitable for the above-mentioned method for preparing hydrazine sulfate, and comprises a micro-mixer, a spiral tube reactor and a cooling tube connected in sequence.

[0025] The input end of the micro-mixer is connected with a first feeding pipe, a second feeding pipe and a third feeding pipe for feeding into the micro-mixer, and the first feeding pipe, the second feeding pipe and the third feeding pipe are respectively used for feeding hydrazine hydrate, concentrated sulfuric acid and fluid conducting medium.

[0026] In the present application, the third feeding pipe for feeding fluid conducting medium is first opened, and then the first feeding pipe and the second feeding pipe for feeding hydrazine hydrate and concentrated sulfuric acid are synchronously opened. Through the conducting effect of the fluid conducting medium, hydrazine hydrate and concentrated sulfuric acid are first rapidly and uniformly mixed in the micropores of the micro-mixer, and then further stably mixed and reacted in the spiral tube reactor. In this process, the fluid conducting medium plays a dilution role on the precipitate mixed solution generated by the reaction of hydrazine hydrate and concentrated sulfuric acid, and improves the flow efficiency of the precipitate mixed solution, thereby avoiding blockage.

[0027] The input end of the micro-mixer is provided with a first feeding port, a second feeding port and a third feeding port for respectively connecting the first feeding pipe, the second feeding pipe and the third feeding pipe.

[0028] Further, the micropore diameter in the micro-mixer is 5-200um.

[0029] Based on this pore size parameter, the sufficient mixing between hydrazine hydrate and concentrated sulfuric acid can be accelerated, and blockage caused by too small pore size can be avoided.

[0030] Further, the micro-mixer is further provided with an ultrasonic generator on the outer wall for emitting ultrasonic waves into the micro-mixer.

[0031] The ultrasonic generator plays a breaking role on the precipitate in the micro-mixer, thereby avoiding the accumulation and blockage of the micropore channels in the micro-mixer.

[0032] Furthermore, a valve component is provided between the spiral tubular reactor and the cooling tube, and the valve component is preferably a ball valve.

[0033] The reactants in the spiral tubular reactor are input into the cooling pipe through the valve component, so as to facilitate the control of the residence time of concentrated sulfuric acid and hydrazine hydrate in the spiral tubular reactor.

[0034] Furthermore, the output port of the spiral tubular reactor is connected to a detection component for detecting temperature and pressure.

[0035] Furthermore, the length of the cooling pipe is 1-4m.

[0036] Furthermore, the inner diameter of the cooling tube is 6-12 mm.

[0037] By setting the above length and inner diameter of the cooling tube, the cooling requirements of the reactants of the present invention can be met, ensuring that a hydrazine sulfate product with high purity and good consistency is produced.

[0038] Furthermore, the first feed pipeline is provided with a first temperature regulating component; and / or the second feed pipeline is provided with a second temperature regulating component; and / or the spiral tubular reactor is provided with a third temperature regulating component.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows: for the first time, a spiral tubular reactor is applied to the condensation reaction of hydrazine hydrate and sulfuric acid, and hydrazine hydrate and concentrated sulfuric acid are pre-mixed using a micro mixer, both by improving mixing efficiency by a micro mixer, and by providing constant temperature and pressure by a spiral tubular reactor, ensuring that the reaction is stably carried out, while increasing the contact area and heat transfer efficiency of the reactant liquid, accelerating the rate of reaction, avoiding the occurrence of uncontrolled high temperature caused by the reaction, improving the yield and purity of hydrazine sulfate, reducing the energy consumption and cost of the reaction, and improving the safety of the reaction. The preparation method provided by the present invention realizes the efficient and energy-saving preparation of hydrazine sulfate, overcomes the shortcomings of traditional kettle reaction speed being slow, uneven mixing, product inhomogeneity, generating unsafe, and has practicality. In addition, the device for preparing hydrazine sulfate provided by the present invention innovatively uses the third strand of conducting medium and ultrasonic mixer to solve the problem that traditional micro mixers are easily blocked. By organically combining the preparation method and preparation device provided by the present invention, the time for the reaction of hydrazine hydrate and concentrated sulfuric acid to generate a hydrazine sulfate product liquid can be controlled to 1-10 minutes, greatly improving the efficiency of preparing hydrazine sulfate. In addition, in industrial production, the preparation device provided by the present invention can be rapidly scaled up by increasing parallel connections, thus having great industrial application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The invention relates to a method for preparing hydrazine sulfate.

[0041] Figure 2 The invention provides a device for preparing hydrazine sulfate.

[0042] Figure numerals: micromixer 1, ultrasonic generator 11, spiral tubular reactor 2, third temperature regulating component 21, cooling pipe 3, discharge port 31, first feed pipeline 4, first feed valve 41, first temperature regulating component 42, second feed pipeline 5, second feed valve 51, second temperature regulating component 52, third feed pipeline 6, third feed valve 61, detection component 7, connecting pipeline 8, ball valve 9. DETAILED DESCRIPTION

[0043] like Figure 1 As shown, the first object of the present invention is to provide a method for preparing hydrazine sulfate, comprising the following steps:

[0044] S1. Hydrazine hydrate and concentrated sulfuric acid are first input into a micromixer for mixing under the conduction effect of a fluid conducting medium and then input into a spiral tubular reactor connected to the micromixer for stabilization and reaction, and then cooled to obtain an intermediate product liquid;

[0045] S2. After centrifuging the intermediate product liquid, collecting crystals, and sequentially washing and drying the crystals to obtain hydrazine sulfate.

[0046] The present invention first realizes the rapid and uniform mixing of hydrazine hydrate and sulfuric acid by micro mixer, improves the selectivity and conversion rate of reaction, introduces fluid conducting medium again, the circulation efficiency of hydrazine hydrate and concentrated sulfuric acid in whole reaction process is promoted based on the conduction effect of fluid conducting medium, avoids the precipitation produced by reaction in micro mixer and causes blockage due to running too slowly, thereafter, hydrazine hydrate and sulfuric acid are further fully mixed and reacted by spiral tubular reactor, improves the uniformity and stability of reaction, realizes the continuous production of reaction simultaneously, improves the quality, consistency and preparation efficiency of product. The present invention is based on the organic combination of fluid conducting medium, micro mixer and spiral tubular reactor, makes hydrazine hydrate and concentrated sulfuric acid realize the continuous reaction similar to plug flow, reduces back mixing phenomenon, improves the selectivity and conversion rate of reaction, realizes the heat exchange efficiency of reaction simultaneously, avoids the occurrence of side reaction, effectively solves the drawbacks of hydrazine sulfate preparation efficiency low, poor safety.

[0047] During specific implementation, the cooling device for cooling treatment is also connected to the spiral tubular reactor, so that the micro mixer, the spiral tubular reactor, and the cooling device are connected in sequence. Through the conduction effect of the fluid conducting medium, hydrazine hydrate and concentrated sulfuric acid achieve an efficient continuous mixed reaction, and then the cooling device can be efficiently cooled to obtain a hydrazine sulfate product liquid. The product liquid is then separated, washed, and dried in conventional post-processing steps to obtain hydrazine sulfate. In a preferred embodiment, the micro mixer, the spiral tubular reactor, and the cooling device are connected in sequence in the horizontal direction, so that the fluid conducting medium can achieve a plug flow-like mixing of hydrazine hydrate and concentrated sulfuric acid in the entire reaction process, greatly improving the uniformity and stability of the material mixing, so that the obtained hydrazine sulfate is of good quality and high yield, and the preparation process is safe and controllable.

[0048] In some embodiments, the mass concentration of hydrazine hydrate can be 70%-90%, and the mass concentration of concentrated sulfuric acid can be 80%-98%. In specific implementations, hydrazine hydrate can be used in concentrations such as 70%, 75%, 80%, 85%, 90%, and the mass concentration of concentrated sulfuric acid can be used in concentrations such as 80%, 85%, 90%, 95%, 98%. In a preferred embodiment, 80% wt of hydrazine hydrate and 98 wt% of concentrated sulfuric acid are used.

[0049] In some embodiments, the temperature of hydrazine hydrate is adjusted to 20°C-80°C before being input into the micromixer. In specific implementation, temperature conditions such as 20°C, 25°C, 30°C, 35°C, 40°C, 50°C, 60°C, 70°C, and 80°C can be adopted. In particular, when 20°C is selected, the purity and yield of hydrazine sulfate obtained are optimal.

[0050] In some embodiments, the temperature of concentrated sulfuric acid is adjusted to 20°C-80°C before being input into the micromixer. More preferably, the temperature of concentrated sulfuric acid is adjusted to 20°C-60°C before being input into the micromixer to optimize the purity and yield of hydrazine sulfate. In specific implementation, temperature conditions such as 20°C, 25°C, 30°C, 35°C, 40°C, 50°C, and 60°C can be adopted.

[0051] In some embodiments, the molar ratio of the feed amounts of hydrazine hydrate and concentrated sulfuric acid is 1:1-1:3. Preferably, the molar ratio can be selected to be 1:1.45-1:3, which helps to improve the purity and yield of the prepared hydrazine sulfate. In specific implementation, the molar ratio can be 1:1.45, 1:1.5, 1:1.8, 1:1.5, 1:2, 1:2.2, 1:2.5, 1:2.8, 1:3, etc.

[0052] In some embodiments, in order to ensure that the hydrazine hydrate and concentrated sulfuric acid can be guided throughout, the fluid conducting medium is introduced into the micromixer, and then hydrazine hydrate and concentrated sulfuric acid are simultaneously introduced into the micromixer.

[0053] In some embodiments, the flow rate of hydrazine hydrate introduced into the micro-mixer is 0.05-1 L / min. It is found that when the flow rate is higher than 1 L / min, the residence time of hydrazine hydrate in the micro-mixer is too short, resulting in poor mixing effect and incomplete reaction, which affects the yield of hydrazine sulfate. When the flow rate is lower than 0.05 L / min, the residence time of hydrazine hydrate in the micro-mixer is too long, resulting in accumulation of the precipitate generated by the reaction with concentrated sulfuric acid, which easily causes blockage and prolongs the reaction time, affecting the preparation efficiency of hydrazine sulfate. In order to obtain better purity and yield of hydrazine sulfate, the flow rate of hydrazine hydrate introduced into the micro-mixer is preferably 0.05-0.3 L / min, and in specific implementation, it can be set to 0.05 L / min, 0.1 L / min, 0.2 L / min, 0.3 L / min, etc.

[0054] In some embodiments, the flow rate of concentrated sulfuric acid introduced into the micro-mixer is 0.05-1 L / min. As in the case of hydrazine hydrate described above, when the flow rate is higher than 1 L / min, the residence time of concentrated sulfuric acid in the micro-mixer and the spiral pipe reactor is too short, resulting in poor mixing effect and incomplete reaction, which affects the yield of hydrazine sulfate. When the flow rate is lower than 0.05 L / min, the residence time of concentrated sulfuric acid in the micro-mixer and the spiral pipe reactor is too long, resulting in accumulation of the precipitate generated by the reaction with hydrazine hydrate, which easily causes blockage and prolongs the reaction time, affecting the preparation efficiency of hydrazine sulfate. The flow rate is preferably 0.05-0.3 L / min, and in specific implementation, it can be set to 0.05 L / min, 0.1 L / min, 0.2 L / min, 0.3 L / min, etc.

[0055] In some embodiments, the flow rate of the fluid conducting medium input into the micro-mixer is 1-3 L / min, i.e. the flow rate of the fluid conducting medium when conducting hydrazine hydrate and concentrated sulfuric acid is 1-3 L / min. In the present application, the fluid conducting medium has the effect of facilitating the delivery of hydrazine hydrate and concentrated sulfuric acid. Research shows that when the flow rate of the fluid conducting medium is greater than 3 L / min, the residence time of hydrazine hydrate and concentrated sulfuric acid in the micro-mixer and the spiral pipe reactor is too short, which fails to perform sufficient mixing reaction, resulting in significant decrease in the yield of hydrazine sulfate. When the flow rate of the fluid conducting medium is less than 1 L / min, the reaction time of hydrazine hydrate and concentrated sulfuric acid is too long, which has the risk of generating side reactions and reduces the preparation efficiency of hydrazine sulfate. In order to ensure efficient preparation of hydrazine sulfate with better purity and yield, the flow rate of the fluid conducting medium input into the micro-mixer is preferably 1-1.5 L / min, and in specific implementation, it can be set to 1 L / min, 1.1 L / min, 1.2 L / min, 1.3 L / min, 1.4 L / min, 1.5 L / min, etc.

[0056] In some embodiments, in order to obtain better conducting effect, the pressure of the fluid conducting medium input into the micro-mixer is 1-10 atm.

[0057] In some embodiments, in order to have a good conductive effect on hydrazine hydrate and concentrated sulfuric acid, the fluid conductive medium is a mixture of any one or more of water, methanol, ethanol, air, nitrogen, and oxygen.

[0058] In some embodiments, in order to maintain hydrazine hydrate and concentrated sulfuric acid at a suitable mixing temperature, the reaction temperature in the micromixer is set to 40-80°C. In a preferred embodiment, in order to optimize the temperature regulation effect, the temperature in the micromixer is preferably adjusted to 40-80°C before hydrazine hydrate, concentrated sulfuric acid, and the fluid conducting medium are input into the micromixer. In specific implementation, temperature conditions such as 40°C, 50°C, 60°C, 70°C, and 80°C can be adopted.

[0059] In some embodiments, the reaction temperature in the spiral tubular reactor is set to 40-80°C. Studies have shown that when the reaction temperature is higher than 80°C, the side reaction between hydrazine hydrate and concentrated sulfuric acid increases, resulting in a downward trend in the yield and purity of hydrazine sulfate. When the reaction temperature is lower than 40°C, the reaction rate of hydrazine hydrate and concentrated sulfuric acid decreases, which also leads to a decrease in the yield and purity of hydrazine sulfate. In specific implementation, the reaction temperature of the spiral tubular reactor can be set to 40°C, 50°C, 60°C, 70°C, 80°C, etc.

[0060] In some embodiments, in order to improve the stability of the reaction between concentrated sulfuric acid and hydrazine hydrate, the reaction pressure in the spiral tubular reactor is set to 1-10 atm.

[0061] In some embodiments, during the cooling process, the cooling temperature is set to 0-25°C. Studies have found that within this temperature range, the efficiency of cooling to produce hydrazine sulfate can be improved, and the obtained hydrazine sulfate product can be ensured to have good purity and yield.

[0062] like Figure 2 As shown, the second object of the present invention is to provide a device for preparing hydrazine sulfate, which is suitable for the above-mentioned method for preparing hydrazine sulfate, comprising a micro mixer 1, a spiral tubular reactor 2 and a cooling tube 3 connected in sequence. In specific implementation, in order to facilitate the connection and combination of each module, a connecting pipe 8 is provided between the micro mixer 1, the spiral tubular reactor 2 and the cooling tube 3.

[0063] Specifically, the input end of the micro mixer 1 is connected to a first feed line 4, a second feed line 5, and a third feed line 6 for entering the interior of the micro mixer 1. The first feed line 4, the second feed line 5, and the third feed line 6 are respectively used to input hydrazine hydrate, concentrated sulfuric acid, and a fluid conducting medium. During implementation, in order to facilitate the control of feeding, the feed port of the first feed line 4 is provided with a first feed valve 41, the feed port of the second feed line 5 is provided with a second feed valve 51, and the feed port of the third feed line 6 is provided with a third feed valve 61. In addition, the micro mixer 1, the spiral tubular reactor 2, and the cooling tube 3 are preferably connected horizontally, so that the mixed material is transported horizontally as a whole throughout the reaction process, and the conducting effect of the fluid conducting medium facilitates the material to achieve a mixing reaction similar to a plug flow.

[0064] In order to improve the conduction efficiency, the third feed line 6 is arranged between the first feed line 4 and the second feed line 5. Specifically, the input end of the micro mixer is provided with a first feed port, a second feed port and a third feed port, and the first feed port, the second feed port and the third feed port are respectively connected to the first feed line 4, the second feed line 5 and the third feed line 6, wherein the third feed port is arranged between the first feed port and the second feed port. Since the materials input through the first feed line 4, the second feed line 5 and the third feed line 6 can only be mixed after being brought together in the micro mixer 1, this pipeline arrangement can shorten the coordination path between the third feed line 6 and the first feed line 4 and the second feed line 5. On the other hand, it can also achieve the simultaneous conduction of the two reaction raw materials, concentrated sulfuric acid and hydrazine hydrate, through only one fluid conducting medium, thereby simplifying the overall structure of the device for preparing hydrazine sulfate.

[0065] In order to obtain a better mixing effect, the micropore diameter inside the micro mixer 1 is 5-200 μm. Based on this pore diameter parameter, the sufficient mixing between hydrazine hydrate and concentrated sulfuric acid can be accelerated, and blockage caused by too small pore diameter can be avoided.

[0066] An ultrasonic generator 11 is provided on the outer wall of the micromixer 1 for emitting ultrasonic waves into the micromixer 1 . The ultrasonic generator 11 breaks up the sediment in the micromixer 1 , preventing the sediment from accumulating and clogging the microporous channels inside the micromixer 1 .

[0067] In order to control the rate at which the reaction liquid generated in the spiral tubular reactor 2 is transported to the cooling tube 3, a valve component is further provided between the spiral tubular reactor 2 and the cooling tube 3, which also helps to control the residence time of the concentrated sulfuric acid and hydrazine hydrate in the spiral tubular reactor 2. In a specific implementation, in order to improve control accuracy, the valve component adopts a ball valve 9.

[0068] In specific implementation, the length of the cooling pipe 3 is 1-4 m, and / or the inner diameter of the cooling pipe 3 is 6-12 mm. By setting the length and the inner diameter of the cooling pipe 3, the cooling requirement of the reactant liquid in the present application can be met, and the product of hydrazine sulfate with high purity and good consistency can be ensured. Specifically, in order to be suitable for the reaction environment of hydrazine hydrate and concentrated sulfuric acid, the cooling pipe 3 is a PE plastic pipe.

[0069] In addition, in order to more accurately regulate the temperature during the reaction, the first feeding pipe 4 is provided with a first temperature adjusting component 42, and / or the second feeding pipe 5 is provided with a second temperature adjusting component 52, and / or the spiral pipe type reactor 2 is provided with a third temperature adjusting component 21. In specific implementation, the first temperature adjusting component 42, the second temperature adjusting component 52 and the third temperature adjusting component 21 can all be realized by the following way: a heat conducting medium is arranged on the four sides of the corresponding component, and the temperature of the corresponding heat conducting medium is adjusted to realize the adjustment of the internal environment temperature of the corresponding component.

[0070] The output port of the spiral pipe type reactor 2 is also communicated with a detection component 7, which is convenient for the operator to intuitively view the real-time temperature and pressure inside the spiral pipe type reactor 2 and to accurately regulate and control accordingly.

[0071] The specific working mode of the present application is as follows: first, the temperatures of the first temperature adjusting component 42, the second temperature adjusting component 52, the third temperature adjusting component 21 and the cooling pipe are adjusted according to the preset temperature regulation, then the third feeding valve 61 is opened to make the fluid conducting medium pass through the third feeding pipe 6 and input into the micro-mixer 1, and then the first feeding valve 41 and the second feeding valve 51 are synchronously opened to make the hydrazine hydrate and the concentrated sulfuric acid pass through the first feeding pipe 4 and the second feeding pipe 5 respectively and input into the micro-mixer 1 under the conducting action of the fluid conducting medium. After the hydrazine hydrate and the concentrated sulfuric acid are rapidly and uniformly mixed by the micropores of the micro-mixer 1, they are input into the spiral pipe type reactor 2 for stabilization and reaction. In this process, the fluid conducting medium can dilute the precipitated mixed liquid generated by the reaction of the hydrazine hydrate and the concentrated sulfuric acid and improve the flow efficiency of the precipitated mixed liquid to avoid blockage. The hydrazine hydrate and the concentrated sulfuric acid are reacted in the spiral pipe type reactor 2, and then continue to be transported into the cooling pipe 3 for cooling to prepare the intermediate product liquid. The intermediate product liquid is output through the discharge port 31 of the cooling pipe 3 and is further separated, washed and dried to prepare the hydrazine sulfate.

[0072] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0073] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained by commercial channels by those skilled in the art.

[0074] Spiral tube reactor: Changzhou Nayang Biotechnology Co., Ltd., model NYB-YN-2X c .

[0075] Micro-mixer: Changzhou Nayang Biotechnology Co., Ltd., metal micro-dispersion pre-mixing micro-reactor.

[0076] Example 1

[0077] The molar ratio of the feed amount of hydrazine hydrate (concentration of 80%) to concentrated sulfuric acid (concentration of 98%) was 1:1.45, the feed flow rate of hydrazine hydrate was 0.3 L / min, and the flow rate of the conducting medium (air) was 1.5 L / min. The preheating temperature of concentrated sulfuric acid was set to 60°C, and the preheating temperature of hydrazine hydrate was 20°C. The preheating temperature of the micro-mixer was 60°C. The temperature of the spiral tube was 60°C, and the cooling tube cold temperature was 0°C. The product liquid obtained after the reaction was centrifugally separated and crystallized, washed with anhydrous ethanol, and air-dried at room temperature to obtain the finished product. The reaction residence time of this method was 2.18 min, the yield of hydrazine sulfate calculated from hydrazine hydrate was 99.4%, and the purity of hydrazine sulfate was 99.4%.

[0078] Example 2

[0079] The molar ratio of the feed amount of hydrazine hydrate (concentration of 80%) to concentrated sulfuric acid (concentration of 98%) was 1:2, the feed flow rate of hydrazine hydrate was 0.3 L / min, and the flow rate of the conducting medium (air) was 1.5 L / min. The preheating temperature of concentrated sulfuric acid was set to 60°C, and the preheating temperature of hydrazine hydrate was 20°C. The preheating temperature of the micro-mixer was 60°C. The temperature of the spiral tube was 60°C, and the cooling tube cold temperature was 0°C. The product liquid obtained after the reaction was centrifugally separated and crystallized, washed with anhydrous ethanol, and air-dried at room temperature to obtain the finished product. The reaction residence time of this method was 1.78 min, the yield of hydrazine sulfate calculated from hydrazine hydrate was 99.0%, and the purity of hydrazine sulfate was 99.3%.

[0080] Example 3

[0081] Hydrazine hydrate (80% concentration) and concentrated sulphuric acid (98% concentration) were fed in a molar ratio of 1 :3. The flow rate of hydrazine hydrate was 0.3 L / min and the flow rate of the conducting medium (air) was 1.5 L / min. The preheating temperature of concentrated sulphuric acid was set at 60 °C and the preheating temperature of hydrazine hydrate was 20 °C. The preheating temperature of the micro-mixer was 60 °C. The temperature of the spiral tube was 60 °C and the temperature of the cooling tube was 0 °C. The product liquid obtained after the reaction was separated by centrifugation and crystallization, washed with absolute ethanol and air dried at room temperature to obtain the finished product. The reaction residence time for this process was 1.33 min and the yield of hydrazine sulphate was 98.4% based on hydrazine hydrate. The purity of hydrazine sulphate was 99.3%.

[0082] Example 4

[0083] Hydrazine hydrate (80% concentration) and concentrated sulphuric acid (98% concentration) were fed in a molar ratio of 1 :1.45. The flow rate of hydrazine hydrate was 0.5 L / min and the flow rate of the conducting medium (air) was 1.5 L / min. The preheating temperature of concentrated sulphuric acid was set at 60 °C and the preheating temperature of hydrazine hydrate was 20 °C. The preheating temperature of the micro-mixer was 60 °C. The temperature of the spiral tube was 60 °C and the temperature of the cooling tube was 0 °C. The product liquid obtained after the reaction was separated by centrifugation and crystallization, washed with absolute ethanol and air dried at room temperature to obtain the finished product. The reaction residence time for this process was 1.31 min and the yield of hydrazine sulphate was 99.4% based on hydrazine hydrate. The purity of hydrazine sulphate was 99.4%.

[0084] Example 5

[0085] Hydrazine hydrate (80% concentration) and concentrated sulphuric acid (98% concentration) were fed in a molar ratio of 1 :1.45. The flow rate of hydrazine hydrate was 0.10 L / min and the flow rate of the conducting medium (air) was 1.5 L / min. The preheating temperature of concentrated sulphuric acid was set at 60 °C and the preheating temperature of hydrazine hydrate was 20 °C. The preheating temperature of the micro-mixer was 60 °C. The temperature of the spiral tube was 60 °C and the temperature of the cooling tube was 0 °C. The product liquid obtained after the reaction was separated by centrifugation and crystallization, washed with absolute ethanol and air dried at room temperature to obtain the finished product. The reaction residence time for this process was 6.53 min and the yield of hydrazine sulphate was 99.6% based on hydrazine hydrate. The purity of hydrazine sulphate was 99.1%.

[0086] Example 6

[0087] Hydrazine hydrate (80% concentration) and concentrated sulphuric acid (98% concentration) were fed in a molar ratio of 1 : 1.45 with a flow rate of 0.05 L / min for hydrazine hydrate and 1.5 L / min for the conducting medium (air). The preheating temperature for concentrated sulphuric acid was set at 60 °C and for hydrazine hydrate at 20 °C. The preheating temperature for the micromixer was 60 °C. The temperature of the spiral tube was 60 °C and the cooling tube was at 0 °C. The product liquid obtained after the reaction was separated by centrifugation and crystallization, washed with absolute ethanol and air dried at room temperature to obtain the finished product. The reaction residence time for this process was 13.06 min and the yield of hydrazine sulphate was 99.6% based on hydrazine hydrate with a purity of 98.4%.

[0088] Example 7

[0089] Hydrazine hydrate (80% concentration) and concentrated sulphuric acid (98% concentration) were fed in a molar ratio of 1 : 1.45 with a flow rate of 0.3 L / min for hydrazine hydrate and 1.0 L / min for the conducting medium (air). The preheating temperature for concentrated sulphuric acid was set at 60 °C and for hydrazine hydrate at 20 °C. The preheating temperature for the micromixer was 60 °C. The temperature of the spiral tube was 60 °C and the cooling tube was at 0 °C. The product liquid obtained after the reaction was separated by centrifugation and crystallization, washed with absolute ethanol and air dried at room temperature to obtain the finished product. The reaction residence time for this process was 2.86 min and the yield of hydrazine sulphate was 99.5% based on hydrazine hydrate with a purity of 99.4%.

[0090] Example 8

[0091] Hydrazine hydrate (80% concentration) and concentrated sulphuric acid (98% concentration) were fed in a molar ratio of 1 : 1.45 with a flow rate of 0.3 L / min for hydrazine hydrate and 3.0 L / min for the conducting medium (air). The preheating temperature for concentrated sulphuric acid was set at 60 °C and for hydrazine hydrate at 20 °C. The preheating temperature for the micromixer was 60 °C. The temperature of the spiral tube was 60 °C and the cooling tube was at 0 °C. The product liquid obtained after the reaction was separated by centrifugation and crystallization, washed with absolute ethanol and air dried at room temperature to obtain the finished product. The reaction residence time for this process was 0.14 min and the yield of hydrazine sulphate was 80.5% based on hydrazine hydrate with a purity of 97.5%.

[0092] Example 9

[0093] The molar ratio of the feed amount of hydrazine hydrate (concentration of 80%) to concentrated sulfuric acid (concentration of 98%) is 1:1.45, the feed flow rate of hydrazine hydrate is 0.3L / min, and the flow rate of the conducting medium (air) is 1.5L / min. The preheating temperature of the concentrated sulfuric acid is set to 60°C, and the preheating temperature of the hydrazine hydrate is 40°C. The preheating temperature of the micro mixer is 60°C. The temperature of the spiral tube is 60°C, and the cooling temperature of the cooling tube is 0°C. After the reaction, the obtained product liquid is centrifuged and crystallized, washed with anhydrous ethanol, and air-dried at room temperature to obtain the finished product. The reaction residence time of this method is 2.18 minutes, the yield of hydrazine sulfate calculated based on hydrazine hydrate is 91.4%, and the purity of hydrazine sulfate is 99.2%.

[0094] Example 10

[0095] The molar ratio of the feed amount of hydrazine hydrate (concentration of 80%) to concentrated sulfuric acid (concentration of 98%) is 1:1.45, the feed flow rate of hydrazine hydrate is 0.3L / min, and the flow rate of the conducting medium (air) is 1.5L / min. The preheating temperature of the concentrated sulfuric acid is set to 60°C, and the preheating temperature of the hydrazine hydrate is 60°C. The preheating temperature of the micro mixer is 60°C. The temperature of the spiral tube is 60°C, and the cooling temperature of the cooling tube is 0°C. After the reaction, the obtained product liquid is centrifuged and crystallized, washed with anhydrous ethanol, and air-dried at room temperature to obtain the finished product. The reaction residence time of this method is 2.18min, the yield of hydrazine sulfate calculated based on hydrazine hydrate is 80.1%, and the purity of hydrazine sulfate is 99.3%.

[0096] Example 11

[0097] The molar ratio of the feed amount of hydrazine hydrate (concentration of 80%) to concentrated sulfuric acid (concentration of 98%) is 1:1.45, the feed flow rate of hydrazine hydrate is 0.3L / min, and the flow rate of the conducting medium (air) is 1.5L / min. The preheating temperature of the concentrated sulfuric acid is set to 40°C, and the preheating temperature of the hydrazine hydrate is 20°C. The preheating temperature of the micro mixer is 60°C. The temperature of the spiral tube is 60°C, and the cooling temperature of the cooling tube is 0°C. After the reaction, the obtained product liquid is centrifuged and crystallized, washed with anhydrous ethanol, and air-dried at room temperature to obtain the finished product. The reaction residence time of this method is 2.18min, the yield of hydrazine sulfate calculated based on hydrazine hydrate is 99.0%, and the purity of hydrazine sulfate is 99.5%.

[0098] Example 12

[0099] Hydrazine hydrate (80% concentration) and concentrated sulphuric acid (98% concentration) were fed in a molar ratio of 1 : 1.45 with a flow rate of 0.3 L / min for hydrazine hydrate and 1.5 L / min for the conducting medium (air). The preheating temperature for concentrated sulphuric acid was set at 20 °C and for hydrazine hydrate at 20 °C. The preheating temperature for the micromixer was 60 °C. The temperature of the spiral tube was 60 °C and the cooling tube was at 0 °C. The product liquid obtained after the reaction was separated by centrifugation and crystallization, washed with absolute ethanol and air dried at room temperature to obtain the finished product. The reaction residence time for this process was 2.18 min and the yield of hydrazine sulphate was 97.1% based on hydrazine hydrate with a purity of 99.4%.

[0100] Example 13

[0101] Hydrazine hydrate (80% concentration) and concentrated sulphuric acid (98% concentration) were fed in a molar ratio of 1 : 1.45 with a flow rate of 0.3 L / min for hydrazine hydrate and 1.5 L / min for the conducting medium (air). The preheating temperature for concentrated sulphuric acid was set at 60 °C and for hydrazine hydrate at 20 °C. The preheating temperature for the micromixer was 60 °C. The temperature of the spiral tube was 40 °C and the cooling tube was at 0 °C. The product liquid obtained after the reaction was separated by centrifugation and crystallization, washed with absolute ethanol and air dried at room temperature to obtain the finished product. The reaction residence time for this process was 2.18 min and the yield of hydrazine sulphate was 99.1% based on hydrazine hydrate with a purity of 99.4%.

[0102] Example 14

[0103] Hydrazine hydrate (80% concentration) and concentrated sulphuric acid (98% concentration) were fed in a molar ratio of 1 : 1.45 with a flow rate of 0.3 L / min for hydrazine hydrate and 1.5 L / min for the conducting medium (air). The preheating temperature for concentrated sulphuric acid was set at 60 °C and for hydrazine hydrate at 20 °C. The preheating temperature for the micromixer was 60 °C. The temperature of the spiral tube was 80 °C and the cooling tube was at 0 °C. The product liquid obtained after the reaction was separated by centrifugation and crystallization, washed with absolute ethanol and air dried at room temperature to obtain the finished product. The reaction residence time for this process was 2.18 min and the yield of hydrazine sulphate was 99.2% based on hydrazine hydrate with a purity of 99.2%.

[0104] Example 15

[0105] Hydrazine hydrate (80% concentration) and concentrated sulphuric acid (98% concentration) were fed in a molar ratio of 1 : 1.45 with a feed rate of 0.3 L / min and a flow rate of 1.5 L / min of conducting medium (air). The preheating temperature of concentrated sulphuric acid was set at 60 °C and that of hydrazine hydrate at 20 °C. The preheating temperature of the micro-mixer was 60 °C. The temperature of the coil was 60 °C and that of the cooling tube was 25 °C. The product liquid obtained after the reaction was separated by centrifugation and crystallization, washed with absolute ethanol and air dried at room temperature to obtain the finished product. The reaction residence time for this process was 2.18 min and the yield of hydrazine sulphate was 98.0% based on hydrazine hydrate with a purity of 99.1%.

[0106] Comparative Example 1

[0107] Hydrazine hydrate (80% concentration) and concentrated sulphuric acid (98% concentration) were fed in a molar ratio of 2: 1 with a feed rate of 0.3 L / min and a flow rate of 1.5 L / min of conducting medium (air). The preheating temperature of concentrated sulphuric acid was set at 60 °C and that of hydrazine hydrate at 20 °C. The preheating temperature of the micro-mixer was 60 °C. The temperature of the coil was 60 °C and that of the cooling tube was 0 °C. The product liquid obtained after the reaction was separated by centrifugation and crystallization, washed with absolute ethanol and air dried at room temperature to obtain the finished product. The reaction residence time for this process was 3.56 min and the yield of hydrazine sulphate was 47.6% based on hydrazine hydrate with a purity of 99.2%.

[0108] Comparative Example 2

[0109] Hydrazine hydrate (80% concentration) and concentrated sulphuric acid (98% concentration) were fed in a molar ratio of 1 : 3.5 with a feed rate of 0.3 L / min and a flow rate of 1.5 L / min of conducting medium (air). The preheating temperature of concentrated sulphuric acid was set at 60 °C and that of hydrazine hydrate at 20 °C. The preheating temperature of the micro-mixer was 60 °C. The temperature of the coil was 60 °C and that of the cooling tube was 0 °C. The product liquid obtained after the reaction was separated by centrifugation and crystallization, washed with absolute ethanol and air dried at room temperature to obtain the finished product. The reaction residence time for this process was 1.19 min and the yield of hydrazine sulphate was 99.4% based on hydrazine hydrate with a purity of 99.2%.

[0110] Comparative Example 3

[0111] Hydrazine hydrate (80% concentration) and concentrated sulphuric acid (98% concentration) were fed in a molar ratio of 1 : 1.45 with a flow rate of 0.04 L / min for hydrazine hydrate and 1.5 L / min for the conducting medium (air). The preheating temperature for concentrated sulphuric acid was set at 60 °C and for hydrazine hydrate at 20 °C. The preheating temperature for the micro-mixer was 60 °C. The temperature of the coil was 60 °C and the cooling tube was at 0 °C. The product liquid obtained after the reaction was separated by centrifugation and crystallization, washed with absolute ethanol and air dried at room temperature to obtain the finished product. The reaction residence time for this process was 16.33 min and the yield of hydrazine sulphate was 99.6% based on hydrazine hydrate with a purity of 99.4%.

[0112] Comparative Example 4

[0113] Hydrazine hydrate (80% concentration) and concentrated sulphuric acid (98% concentration) were fed in a molar ratio of 1 : 1.45 with a flow rate of 0.3 L / min for hydrazine hydrate and 4.0 L / min for the conducting medium (air). The preheating temperature for concentrated sulphuric acid was set at 60 °C and for hydrazine hydrate at 20 °C. The preheating temperature for the micro-mixer was 60 °C. The temperature of the coil was 60 °C and the cooling tube was at 0 °C. The product liquid obtained after the reaction was separated by centrifugation and crystallization, washed with absolute ethanol and air dried at room temperature to obtain the finished product. The reaction residence time for this process could not be determined and the yield of hydrazine sulphate was 51.4% based on hydrazine hydrate with a purity of 95.4%.

[0114] Comparative Example 5

[0115] Hydrazine hydrate (80% concentration) and concentrated sulphuric acid (98% concentration) were fed in a molar ratio of 1 : 1.45 with a flow rate of 0.3 L / min for hydrazine hydrate and 1.5 L / min for the conducting medium (air). The preheating temperature for concentrated sulphuric acid was set at 60 °C and for hydrazine hydrate at 70 °C. The preheating temperature for the micro-mixer was 60 °C. The temperature of the coil was 60 °C and the cooling tube was at 0 °C. The product liquid obtained after the reaction was separated by centrifugation and crystallization, washed with absolute ethanol and air dried at room temperature to obtain the finished product. The reaction residence time for this process was 2.18 min and the yield of hydrazine sulphate was 68.9% based on hydrazine hydrate with a purity of 99.0%.

[0116] Comparative Example 6

[0117] The molar ratio of the feed amount of hydrazine hydrate (concentration of 80%) to concentrated sulfuric acid (concentration of 98%) is 1:1.45, the feed flow rate of hydrazine hydrate is 0.3L / min, and the flow rate of the conducting medium (air) is 1.5L / min. The preheating temperature of the concentrated sulfuric acid is set to 0°C, and the preheating temperature of the hydrazine hydrate is 20°C. The preheating temperature of the micro mixer is 60°C. The temperature of the spiral tube is 60°C, and the cooling temperature of the cooling tube is 0°C. After the reaction, the obtained product liquid is centrifuged and crystallized, washed with anhydrous ethanol, and air-dried at room temperature to obtain the finished product. The reaction residence time of this method is 2.18 minutes, the yield of hydrazine sulfate calculated based on hydrazine hydrate is 95.0%, and the purity of hydrazine sulfate is 99.2%.

[0118] Comparative Example 7

[0119] The molar ratio of the feed amount of hydrazine hydrate (concentration of 80%) to concentrated sulfuric acid (concentration of 98%) is 1:1.45, the feed flow rate of hydrazine hydrate is 0.3L / min, and the flow rate of the conducting medium (air) is 1.5L / min. The preheating temperature of the concentrated sulfuric acid is set to 60°C, and the preheating temperature of the hydrazine hydrate is 20°C. The preheating temperature of the micro mixer is 60°C. The temperature of the spiral tube is 100°C, and the cooling temperature of the cooling tube is 0°C. After the reaction, the obtained product liquid is centrifuged and crystallized, washed with anhydrous ethanol, and air-dried at room temperature to obtain the finished product. The reaction residence time of this method is 2.18min, the yield of hydrazine sulfate calculated based on hydrazine hydrate is 95.3%, and the purity of hydrazine sulfate is 98.5%.

[0120] Comparative Example 8

[0121] (1) In the presence of a catalyst (8 g for zinc, 30 g for copper, and 30 g for nickel), 1200 g of benzophenone was placed in a reactor and stirred uniformly at 500-1000 rpm at 180-200° C., while ammonia and air were continuously introduced, wherein the average aeration ratio of ammonia to air was 1:3. The reaction was continued for 4-10 hours to obtain 60% benzophenone hydrazine.

[0122] (2) adding 10 g of dodecylbenzenesulfonic acid, 120 g of hydrochloric acid, and 1200 mL of water, and carrying out a hydrolysis reaction at 75-95° C. for 4-10 hours, and then adding alkali for neutralization to obtain hydrazine hydrate;

[0123] (3) Add concentrated sulfuric acid to hydrazine hydrate, cool and crystallize, filter, wash and dry to obtain the product hydrazine sulfate.

[0124] The step (2) specifically includes the following steps:

[0125] (31) In the reaction kettle, pure water was added, stirred, and 98% sulfuric acid was slowly added under cooling, and then 80% hydrazine hydrate was added at 70-80°C, and filtered while hot, wherein the mass ratio of pure water, 98% sulfuric acid and 80% hydrazine hydrate was 10:10:4;

[0126] (32) The filtrate was adjusted to pH = 4-5 using sulfuric acid or hydrazine hydrate, stirred for 20-60 minutes, and then cooled to 25°C to crystallize, centrifuged to separate the crystals, washed with anhydrous ethanol, and air-dried at room temperature to obtain the finished product.

[0127] Comparative Example 9

[0128] A mass fraction of 30% sodium hydroxide solution was prepared, and after cooling, chlorine gas was introduced (the entire device was placed in an ice water bath). The rate of chlorine gas introduction was controlled to maintain the solution temperature below 30°C. When the effective chlorine mass fraction of the solution reached 18.56%, the chlorine gas introduction was stopped. A certain amount of sodium hydroxide solution was added to the above solution to prepare a mixture with an effective chlorine mass fraction of about 8% and a free base mass fraction of about 10.8%. 83.7g of NaClO solution was weighed and added to 30mL of water to prepare a mass fraction of 19% NaClO solution, ready for use.

[0129] Hydrazine hydrate was transferred to a beaker, and 75g of 98% concentrated sulfuric acid was added dropwise while stirring, with the dropwise addition time controlled at about 1h and the temperature below 60°C. After cooling and settling for 2h, hydrazine sulfate precipitate was obtained. Filtration was performed, and the precipitate was washed with anhydrous ethanol and dried to obtain white hydrazine sulfate solid with a purity of 95.3% and a melting point of 255°C, with a yield (based on NaClO) of 69.1%.

[0130] Test Analysis

[0131] Table 1. Purity and yield of hydrazine sulfate in Examples 1-15 and Comparative Examples 1-9:

[0132] Group Yield Purity Group Yield Purity Example 1 99.4％ 99.4％ Comparative Example 1 47.6％ 99.2％ Example 2 99.0％ 99.3％ Comparative Example 2 99.4％ 99.2％ Example 3 98.4％ 99.3％ Comparative Example 3 99.6％ 99.4％ Example 4 99.4％ 99.4％ Comparative Example 4 51.4％ 95.4％ Example 5 99.6％ 99.1％ Comparative Example 5 68.9％ 99.0％ Example 6 99.6％ 98.4％ Comparative Example 6 95.0％ 99.2％ Example 7 99.5％ 99.4％ Comparative Example 7 95.3％ 98.5％ Example 8 80.5％ 97.5％ Comparative Example 8 / / Example 9 91.4％ 99.2％ Comparative Example 9 69.1％ 95.3％ Example 10 80.1％ 99.3％ Example 11 99.0％ 99.5％ Example 12 97.1％ 99.4％ Example 13 99.1％ 99.4％ Example 14 99.2％ 99.2％ Example 15 98.0％ 99.1％

[0133] The test results show that, compared with Example 1, the difference between Comparative Example 1 is that the molar ratio of hydrazine hydrate to concentrated sulfuric acid is increased, which causes the phenomenon of insufficient concentrated sulfuric acid during the reaction, resulting in a significant decrease in the yield of hydrazine sulfate;

[0134] Compared with Example 1, the difference between Comparative Example 2 is that the molar ratio of hydrazine hydrate to concentrated sulfuric acid is decreased, although the yield and purity of hydrazine sulfate do not change significantly, but the consumption of concentrated sulfuric acid is large, causing unnecessary waste;

[0135] Compared with Example 1, the difference between Comparative Example 3 is that the flow rate of hydrazine hydrate is significantly reduced, although it does not cause significant changes in the yield and purity of hydrazine sulfate, but the reaction time is significantly prolonged, affecting the efficiency of hydrazine sulfate preparation;

[0136] The difference between Comparative Example 4 and Example 1 is that the flow rate of the conducting medium is increased, which results in too short residence time of hydrazine hydrate and concentrated sulfuric acid in the spiral pipe, and the mixing reaction is not sufficient, which leads to a significant decrease in the yield of hydrazine sulfate;

[0137] The difference between Comparative Example 5 and Example 1 is that the preheating temperature of hydrazine hydrate is increased, which leads to a significant decrease in the yield of hydrazine sulfate, indicating that the preheating temperature of hydrazine hydrate significantly affects the preparation effect of hydrazine sulfate;

[0138] The difference between Comparative Example 6 and Example 1 is that the preheating temperature of concentrated sulfuric acid is reduced, which also leads to a downward trend in the yield of hydrazine sulfate, although the change trend is not large, but also indicates that the preheating temperature of concentrated sulfuric acid is one of the factors affecting the yield of hydrazine sulfate;

[0139] The difference between Comparative Example 7 and Example 1 is that the temperature of the spiral pipe is increased, which leads to an increase in the side reaction between hydrazine hydrate and concentrated sulfuric acid, resulting in a slight decrease in the yield and purity of hydrazine sulfate;

[0140] Compared with Example, Comparative Example 8 uses a conventional kettle reaction, which greatly prolongs the preparation time, resulting in low preparation efficiency of hydrazine sulfate;

[0141] Compared with Example, Comparative Example 9 needs to introduce NaClO solution additionally, which is complicated, and concentrated sulfuric acid needs to be added dropwise, which is low in efficiency, leading to a significant increase in the preparation time and a significant decrease in the yield of hydrazine sulfate calculated by NaClO, which is not conducive to cost control.

[0142] In summary, the present application greatly improves the efficiency of preparing hydrazine sulfate from hydrazine hydrate and concentrated sulfuric acid by using a micro-mixer combined with a spiral tube reactor, and ensures high purity and high yield. A large number of experimental tests show that, by using the following parameters: the molar ratio of the feed amount of hydrazine hydrate to concentrated sulfuric acid is 1:1-1:3, the feed flow rate of hydrazine hydrate and concentrated sulfuric acid is 0.05-1.0 L / min, the flow rate of the conducting medium is 1-3 L / min, the preheating temperature of concentrated sulfuric acid and hydrazine hydrate is set to 20-80℃, the preheating temperature of the micro-mixer is 40-80℃, the reaction temperature of the spiral tube reactor is set to 40-80℃, and the cooling temperature of the cooling tube is set to 0-25℃, the preparation of hydrazine sulfate has better yield and purity; based on the above examples and comparative examples, further comparison and screening of some of the above reaction conditions show that the optimal flow rate of the conducting medium is 1-1.5 L / min, the optimal feed flow rate of hydrazine hydrate and concentrated sulfuric acid is 0.05-0.3 L / min, the optimal preheating temperature of hydrazine hydrate is 20℃, and the optimal preheating temperature of concentrated sulfuric acid is 20-60℃, under these conditions, hydrazine hydrate and concentrated sulfuric acid can be fully mixed and reacted in the micro-channel, and the high reaction temperature can be avoided to cause side reactions or the long reaction time to affect the efficiency, thereby efficiently preparing hydrazine sulfate and ensuring high purity and high yield.

[0143] Obviously, the above examples of the present application are only examples for clearly illustrating the technical solutions of the present application, and are not intended to limit the specific embodiments of the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the protection scope of the claims of the present application.

Claims

1. A method for preparing hydrazine sulfate, characterized in that, The following steps are involved: S1. Hydrazine hydrate and concentrated sulfuric acid are first input into a micromixer for mixing under the conduction effect of a fluid conducting medium and then input into a spiral tubular reactor connected to the micromixer for stabilization and reaction, followed by cooling to obtain an intermediate product liquid, wherein the temperature of hydrazine hydrate is adjusted to 20°C-40°C before inputting into the micromixer, the temperature of concentrated sulfuric acid is adjusted to 20°C-60°C before inputting into the micromixer, the feed amount molar ratio of hydrazine hydrate and concentrated sulfuric acid is 1:1-1:3, the flow rate of hydrazine hydrate input into the micromixer is 0.05-1L / min, the flow rate of the fluid conducting medium input into the micromixer is 1-3L / min, and the reaction temperature in the spiral tubular reactor is set to 40-80°C; S2. After centrifuging the intermediate product liquid, collecting crystals, and sequentially washing and drying the crystals to obtain hydrazine sulfate.

2. The preparation method of hydrazine sulfate according to claim 1, wherein The temperature of hydrazine hydrate was adjusted to 20°C before being input into the micro mixer.

3. The preparation method of hydrazine sulfate according to claim 1, wherein The flow rate of hydrazine hydrate input into the micro mixer is 0.05-0.3 L / min.

4. The preparation method of hydrazine sulfate according to claim 1, wherein The flow rate of concentrated sulfuric acid input into the micro mixer is 0.05-1 L / min.

5. The preparation method of hydrazine sulfate according to claim 4, wherein The flow rate of concentrated sulfuric acid input into the micro mixer is 0.05-0.3 L / min.

6. The preparation method of hydrazine sulfate according to claim 1, wherein The flow rate of the fluid conducting medium input into the micro mixer is 1-1.5 L / min.

7. The preparation method of hydrazine sulfate according to claim 1, wherein The pressure of the fluid conducting medium input into the micro mixer is 1-10 atm.

8. The preparation method of hydrazine sulfate according to claim 1, wherein The fluid conducting medium is a mixture of any one or more of water, methanol, ethanol, air, nitrogen and oxygen.

9. The preparation method of hydrazine sulfate according to claim 1, wherein The reaction temperature in the micro mixer is set to 40-80°C; and / or the pressure in the spiral tubular reactor is set to 1-10 atm; and / or, during the cooling treatment, the cooling temperature is set to 0-25°C.

10. A device for preparing hydrazine sulfate, suitable for the preparation method of hydrazine sulfate according to any one of claims 1 to 9, characterized in that: It comprises a micro mixer, a spiral tubular reactor and a cooling pipe which are connected in sequence; The input end of the micromixer is connected to a first feed pipeline, a second feed pipeline and a third feed pipeline for entering the interior of the micromixer. The first feed pipeline, the second feed pipeline and the third feed pipeline are used to input hydrazine hydrate, concentrated sulfuric acid and a fluid conducting medium, respectively.

11. The device for preparing hydrazine sulfate according to claim 10, characterized in that The micromixer is provided with a first feed port, a second feed port, and a third feed port for connecting to the first feed pipeline, the second feed pipeline, and the third feed pipeline, respectively, and the third feed port is located between the first feed port and the second feed port; and / or the micropores inside the micromixer have a pore diameter of 5-200 μm; and / or an ultrasonic generator for emitting ultrasonic waves into the micromixer is further provided on the outer wall of the micromixer.

12. The device for preparing hydrazine sulfate according to claim 10, characterized in that A valve component is further provided between the spiral tubular reactor and the cooling tube, and the valve component is preferably a ball valve; and / or the output port of the spiral tubular reactor is connected to a detection component for detecting temperature and pressure; and / or the length of the cooling tube is 1-4 m, and / or the inner diameter of the cooling tube is 6-12 mm.

13. The device for preparing hydrazine sulfate according to claim 10, characterized in that The first feed pipeline is provided with a first temperature regulating component; and / or, the second feed pipeline is provided with a second temperature regulating component; and / or, the spiral tubular reactor is provided with a third temperature regulating component.

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