CN211734226U - Micro-reaction equipment for preparing isooctyl nitrate - Google Patents

Abstract

The utility model relates to a little response unit of low operating pressure of high flux of preparation isooctyl nitrate, this equipment have two micro-reactors to establish ties to constitute, have saved and to mix this step of reserve with nitric acid and sulphuric acid in advance, and this equipment includes feed arrangement, little reaction unit and split-phase clarification device, feed arrangement with little reaction unit intercommunication, little reaction unit and split-phase clarification device connect little reaction unit in isooctyl alcohol and nitric acid take place nitration and generate the result. The equipment can be used for amplifying by different times according to production requirements, has no amplification effect and has large treatment capacity. The process for preparing isooctyl nitrate by using the micro-reaction equipment has the advantages of high material utilization rate, high reaction efficiency, short reaction time, low production cost, safety, reliability and the like.

Description

Micro-reaction equipment for preparing isooctyl nitrate

Technical Field

The utility model belongs to the chemical synthesis field, concretely relates to little response device of low operating pressure of high flux of preparation isooctyl nitrate.

Background

Isooctyl nitrate, also known as 2-ethylhexyl nitrate, is a diesel additive which can improve the cetane number of diesel oil, improve the combustion performance of diesel oil, shorten the ignition time, reduce the ignition point, improve the dynamic property of locomotive thermal conditions and have obvious oil-saving effect, and belongs to an important nitrate compound which also plays a wide role in other fields such as aerospace, military application, petroleum processing and the like.

The traditional production process for preparing isooctyl nitrate mostly adopts a mixed acid method, namely, the mixed solution of nitric acid and sulfuric acid and isooctyl alcohol are subjected to nitration reaction in a kettle type reactor in a dropwise adding mode to generate isooctyl nitrate. The reaction process is very dangerous, there is thermal runaway and reaction runaway, both of which can occur explosively. Nitration itself on the one hand just belongs to the strong exothermic reaction, and the water of reaction generation makes concentrated sulfuric acid diluted, also can emit a large amount of dilution heats, if can not be timely with this heat transfer the formation process that can make there is huge potential safety hazard, the danger of exploding easily takes place, local high temperature can make the nitric acid take place to decompose and produce a large amount of nitrogen dioxide gas, polluted environment. Meanwhile, the reaction rate of the side reaction caused by overhigh temperature can be increased, and the purity and the yield of the isooctyl nitrate are reduced. On the other hand, the proportion of reactants is required to be accurate, and the aged plain text of the macro-union chemical-chemical institute discovers that if the proportion of the reactants is not well controlled, the partial mixed acids are nitric acid and isooctyl alcohol<1:1, which can cause the reaction of isooctyl alcohol and sulfuric acid, the generated sulfuric ester is used as a surfactant, the main reaction product, namely nitrate, enters a water phase, and after the critical concentration is reached, the reaction is violentA temperature runaway occurs and an explosion may occur. The traditional kettle type reaction is difficult to control in the two aspects and has great danger. Therefore, the development of intrinsically safe equipment and process for generating isooctyl nitrate needs to solve the problems of rapid heat exchange and rapid mixing of two phases. With the continuous improvement of the synthesis process in the technical development, the problems of jet generation, microchannel or microtube production, and partial mixing and heat transfer occur, but the problems that the single-channel treatment capacity in the amplification process is small, and the system may need high-pressure operation and the like also exist. The published number CN 101462962A of Chenguanghuang et al in the chemical and physical institute of Union mentions that nitric acid mixed sulfate solution and isooctanol react in a Y-shaped microchannel reactor with two reactants forming an included angle of 60-180 DEG, and the liquid hourly space velocity is 3000-^-1The single channel throughput is relatively small. Patent application No. 201410202348 of changzhou university also discloses a method for synthesizing isooctyl nitrate by mixing acid and isooctyl alcohol in a microchannel reactor, the reaction time is 0.5-1 hour, and the method does not specifically indicate how to realize the high residence time in the microreactor, the reaction belongs to a strong exothermic reaction, and the long residence time increases the production safety hazard. And does not disclose how to implement the specific effects. Patent 20151081272 filed by Nanjing university of Physician also discloses the use of microchannel method to prepare isooctyl nitrate to achieve the desired performance. But does not disclose the problem of the throughput of the microchannel reactor, and the problem of whether the microchannel reactor can realize the amplification production and the amplification effect. Meanwhile, the use amount of nitric acid and sulfuric acid in the material proportion disclosed by the patent is too large, so that great problems and economic cost are brought to subsequent waste acid treatment. Although the experiment of recycling the mixed acid is also carried out, the dichloromethane adopted for extraction is a toxic reagent and is listed in a toxic and harmful water pollutant list, and the extraction experiment also needs to consume manpower, material resources and time, so that the production cost is increased and the safety of experimenters is improved. In patent CN 10482425A published by Corning incorporated, isooctyl nitrate was synthesized using microchannel reactors G1 and G4 of the same company with "heart-type" mixing elements, the temperature being controlled at-10 to 35 ℃. Using microchannel microreflectionsThe reactor generally has the problem of small single-channel processing flux, under the condition of no special mixing structure, the mixing under the micro-channel mainly depends on the size of the channel, usually less than 100-; in order to ensure the treatment effect, the reaction tube needs to be greatly prolonged, and the operation pressure is greatly increased; thus, is greatly limited in throughput; for a microreactor with a microchannel reactor having a particular static mixer or other packed structure, such as the corning "heart-type" mixing structure, the operating pressure rises sharply as the flow rate increases. The equipment cost and the operation cost are greatly improved for the microreactor and the conveying equipment which need to bear high pressure. These microchannel technologies are still essentially in the laboratory or bench scale. An example of an application of the patent CN 101698646A to Sienmaded, using a microtubular reactor similar to a microchannel, shows an operating pressure of 1MPa when the theoretical equivalent is 0.1cm for a microreactor and an operating pressure of 3MPa when the theoretical equivalent is 1cm for a microreactor. The technology is industrialized by Ciampandard. However, the single-channel processing capacity of the technology is small, the yield of the micro-tube type production technology adopted by the Seamandd energy chemical company is 1 ten thousand tons per year by the old light character evaluation of the large connected substance, but the defect of the parallel production technology of dozens of lines is obvious. "

SUMMERY OF THE UTILITY MODEL

The invention aims to provide a micro-reaction high-flux low-operation pressure device and a process for preparing isooctyl nitrate. The technical scheme for specifically realizing the aim of the invention is as follows: a high throughput low operating pressure microreaction apparatus for the production of isooctyl nitrate characterized by: the equipment comprises a feeding device, a micro-reaction device and a split-phase clarifying device; the feeding device is communicated with the micro-reaction device, the micro-reaction device phase-splitting clarification device is communicated, and in the micro-reaction device, isooctanol reacts with mixed acid solution of nitric acid/sulfuric acid to generate a product. The equipment omits the step of mixing nitric acid and sulfuric acid in advance, has high safety performance, small volume, large handling capacity and small operation pressure, can carry out amplification of different times according to different requirements of production, and has no amplification effect.

Further, it is characterized in that: the micro-reaction device comprises a first-stage micro-reactor and a second-stage micro-reactor which are connected in sequence. Mixing nitric acid and sulfuric acid in the first-stage microreactor to form mixed acid; and mixing and reacting the mixed acid and the isooctyl alcohol in the second-stage microreactor.

Further, it is characterized in that: the discharge port of the first-stage micro-reactor is communicated with the continuous phase inlet of the second-stage micro-reactor, and the discharge port of the second-stage micro-reactor is connected with a follow-up device.

Further, a dispersing and mixing module is contained in the microreactor; after dispersing the mixing module, a heat transfer module composition may be contained; the dispersion mixing module and the heat transfer module can be separated or integrated; preferably, the microreactor contains a dispersive mixing module and a heat transfer module. The dispersing and mixing module is mainly used for fully mixing the two materials; mainly adopts a microporous membrane or a micro-sieve membrane or a micro-slit membrane design, one component or mixture in the reactant is dispersed into a tiny droplet form through a dispersion medium and enters a mixing channel to be mixed with the other component or mixture of the reactant, wherein one phase dispersed into small droplets is a dispersed phase, and the other phase is not dispersed into a continuous phase called a dispersion membrane. The dispersion medium adopts a microporous membrane or a micro-sieve-pore membrane, the pore diameter of the dispersion membrane is 1-100 microns, the pore diameter of the micro-sieve pore is 50-500 microns, the narrow gap width of the micro-narrow gap membrane is 50-2000 microns, and the dispersion medium is very thin, usually between 100-2000 microns, and the membrane passing resistance is very small. In actual practice, different dispersion media and their size characteristics are selected according to the viscosity of the system and the possible characteristics of solid particles. The design of the micro-mixing module greatly improves the mixing performance among reactants, can realize uniform mixing in millisecond time, and simultaneously reduces the size requirement of subsequent reaction channels (the dimension of the channels is not required to be strictly limited to ensure the mixing performance as a common micro-channel reactor, and the smaller the channel size is, the higher the operating pressure of the same processing capacity is), thereby reducing the operating pressure drop of the system, improving the operating processing capacity and being beneficial to large-scale industrial application. In the first-stage microreactor, the mixing of mixed acid is mainly physical mixing, but the process is equivalent to dilution of concentrated sulfuric acid by water in nitric acid, a large amount of solution heat is generated, reaction heat needs to be removed in time, and otherwise, the decomposition of the nitric acid can be caused; it has been found that nitric acid in mixed acids starts to decompose at 57 c and therefore it is necessary to control the temperature below this temperature. The main reaction in the second-stage microreactor relates to an oil-water two-phase system, and the key for the reaction is the rapid mixing of oil and water phases. The heat transfer module rapidly transfers heat generated by the reaction out, and ensures that the reaction is carried out in a controllable range. The use of the dispersive mixing module strengthens the rapid mixing of two phases, is favorable for improving the rapid reaction, further greatly improves the treatment capacity and provides necessary conditions for high-flux treatment.

Further, it is characterized in that the reactors of two stages are operated in series; the two-stage microreactors have the same structure or may have different structures; the nitric acid and the sulfuric acid are uniformly mixed in the first-stage microreactor, and the mixed acid is further mixed with the isooctyl alcohol in the second-stage microreactor. The design of the two-stage microreactor and the integration of the heat transfer module in the two-stage microreactor improve the heat transfer capacity of the equipment, a large amount of heat generated by mixing nitric acid and sulfuric acid can be transferred out in time, and extra heat cannot be generated by a large amount of hot bands generated by the quick reaction of mixed acid and isooctyl ester, so that the heat load generated by mixing the nitric acid, the sulfuric acid and the isooctyl ester is reduced, the operation tolerance of the equipment is improved, and the possibility of high flux is further provided. Further: the method is characterized in that: the first-stage micro-reactor and the second-stage micro-reactor are similar in structure, wherein each dispersing and mixing module comprises an upper membrane device component, a lower membrane device component, a middle two-layer gasket and a dispersing medium; wherein the dispersion medium is positioned between two layers of gaskets, and the upper membrane device component can be selected as a cooling module component; the lower membrane component is a continuous phase membrane component and a disperse phase membrane component; has a continuous phase inlet, a dispersed phase inlet and a material outlet. Further, it is characterized in that: the dispersion medium includes, but is not limited to, microporous membranes, micromesh pores, and flat slit membranes; preferably, the microporous membrane has a pore size of 1 to 100 microns; preferably, the micro-sieve pore size is 50-600 microns; preferably, the width of the flat-plate-shaped micro narrow slit film is 0.6-2 mm; more preferably, the width of the flat narrow slit film is 0.8-1.0 mm; the pressure difference is used as driving force to realize the fine dispersion phase.

Furthermore, in a mixing channel of the microreactor, the flow velocity in the isooctanol channel is converted to 0.3-2.5 m/s; more preferably 0.5 to 1.5 m/s; further preferably 0.75 to 1.5 m/s.

Further, the micro-reactor contains a mixing module or a heat transfer module; the preferred mixing module is integrated with a heat exchange module within the microreactor. Further, the heat exchange module transfers heat for the micro-channel, and preferably, the equivalent diameter of the channel is 0.5-10 mm; more preferably, the channel size is 0.5-3 mm.

Further, the microreactor system is operated at a pressure of 0.1 to 0.4 MPa. An efficient mixing module is adopted in the microreactor, the flow direction in the mixing module is short, and the operating pressure is reduced; in the subsequent heat exchange module, the channel dimensions can be suitably multiplied by several times. The design of the special structure greatly reduces the operation pressure on the premise of ensuring the full mixing and reaction among reaction materials and efficiently exchanging reaction heat out of the system; the pressure resistance of the equipment and the requirement on a feeding system are reduced.

Compared with the prior art, the micro-reaction equipment and the process for preparing isooctyl nitrate have the following advantages that:

firstly, the dispersed phase can be uniformly dispersed and mixed with the continuous phase in the microreactor, so that the mass transfer surface area is increased, the mass transfer efficiency is improved, the reaction can be carried out under the condition of almost no mass transfer limitation, the reaction is more sufficient, and the reaction efficiency is high; secondly, the micro-reactor has small volume, realizes liquid-liquid mixing by taking the pressure difference of two phases as a driving force, has short retention time and small material retention; thirdly, the isooctyl nitrate prepared by the device has the characteristics of continuous operation, easily controlled reaction conditions, short reaction time, high safety performance and the like, can quickly transfer heat generated by strong exothermic reaction out, and has strong selectivity when used for carrying out quick nitration reaction on isooctyl alcohol; fourthly, the equipment has the advantages that the two-stage microreactors are connected in series, so that the mixed nitric acid and sulfuric acid can quickly react with isooctyl alcohol in time, the step of mixing the nitric acid and the sulfuric acid together in advance before reaction is omitted, the production efficiency is improved, and the cost is saved; fifthly, the special high-efficiency micro-mixing and micro-heat exchange system design realizes high-efficiency mixing and high-efficiency heat exchange and simultaneously realizes low operation pressure drop; sixth, the invention can be applied to the actual production directly, the handling capacity is large, it is easy to enlarge, and can realize the large-scale production according to the actual production need.

Drawings

FIG. 1 is a schematic view of a process flow for preparing isooctyl nitrate by a micro-reaction device;

FIG. 2 schematic representation of a microreactor.

Detailed Description

In order to better understand the present invention for those skilled in the art, the following detailed description of the present invention is provided with reference to the accompanying drawings and the implementation method.

In the drawings, the components represented by the respective reference numerals are listed below:

1 is continuous phase import pipe, 2 dispersion medium membrane, 3 dispersion phase import pipe, 4 reactant outlet pipes, 5 lower component module, 6 mixed channel module, 7 heat transfer module, 8 upper component module: 10, wherein Al, a2, A3 are respectively a first, a second and a third advection pump, R1 is sulfuric acid, R2 is nitric acid, R3 is isooctanol; 20. a micro-reaction device 21, a first-stage micro-reactor 22, a second-stage micro-reactor 23 and a phase separation clarification device.

The utility model discloses a preparation isooctyl nitrate's micro-reaction equipment, including feed arrangement 10 and little reaction unit 20, feed arrangement 10 with little reaction unit 20 intercommunication.

The feeding device comprises a first constant-flow pump Al, a second constant-flow pump A2 and a third constant-flow pump A3, wherein the first constant-flow pump Al is used for conveying sulfuric acid R1, the second constant-flow pump A2 is used for conveying nitric acid R2, and the third constant-flow pump A3 is used for conveying isooctanol R3.

The micro-reaction device 20 comprises two-stage micro-reactors, namely a first-stage micro-reactor 21, a second-stage micro-reactor 22 and a phase separation clarification device 23, wherein a discharge port of the first-stage micro-reactor 21 is communicated with a continuous phase inlet of the second-stage micro-reactor, and a discharge port of the second-stage micro-reactor is communicated with the phase separation clarification device 23. In this stage, the phase separation is relatively fast (oil and water are separated, and a micro-reactor is used for phase separation).

The first and second advection pumps Al and A2 are connected with the first-stage microreactor 21, and the third advection pump A3 is connected with the second-stage microreactor 22. Thus, the sulfuric acid and the nitric acid are mixed in the first-stage microreactor 21 to form mixed acid, and the mixed acid solution and the isooctyl alcohol are mixed and reacted in the second-stage microreactor 22 to generate a product.

Wherein, preferably, a dispersion mixing module is contained in the microreactor 21/22; more preferably, a heat transfer module is also disposed within the microreactor 21/22.

Preferably, the dispersive mixing module comprises an upper film device component 8, a lower film device component 5, a middle two-layer gasket and a dispersion medium film 2; wherein a dispersion medium film 2 is disposed between two spacers, and a continuous phase inlet pipe 1, a dispersed phase inlet pipe 3 and a reactant outlet pipe 4 are provided on a lower membrane element 5.

Within the dispersive mixing module there is a mixing channel 6 which communicates with the continuous phase inlet conduit 1, the dispersed phase inlet conduit 3 and the reactant outlet conduit 4. The material of the dispersed phase inlet pipe 3 is dispersed into a micro liquid drop form through the dispersion medium film 2 and then enters the mixing channel 6 to react with the material entering the mixing channel 6 through the continuous phase inlet pipe 1. The reaction product is discharged through the reactant outlet tube 4.

Preferably, the dispersion medium 2 includes, but is not limited to, a microporous membrane, a micromesh, a narrow slit membrane, or the like; preferably a flat narrow slit film with a width of 0.6-1.0 mm; the aperture of the microporous membrane is preferably 1-100 microns, the selected micromesh is 50-600 microns, and the pressure difference is used as the driving force to realize the micronization of the dispersed phase.

Preferably, the heat transfer module 7 is a micro-channel heat dissipation structure, preferably arranged on the upper membrane element 8, and preferably, the channel equivalent diameter dimension is 0.5-10 mm; more preferably, the channel size is 0.5-3 mm. The channel direction of the channel heat dissipation structure can be vertical or parallel to the mixing channel.

The application also provides a preparation method of isooctyl nitrate, which comprises the steps of inputting sulfuric acid, nitric acid and isooctanol into a micro-reaction device through a first, a second and a third advection pumps A1, A2 and A3 in a continuous mode, leading the nitric acid, the sulfuric acid and the isooctanol to enter a single-channel total flow rate of 226-348ml/min of the micro-reaction device, namely the sum of flow rates of the nitric acid, the sulfuric acid and the isooctanol is 226-348ml/min, mixing the sulfuric acid and the nitric acid at a first-stage microreactor, leading mixed acid solution of the nitric acid and the isooctanol to carry out nitration reaction at a second-stage microreactor, leading out a water-oil mixture from the second-stage microreactor after static phase separation in a phase separation clarifying tank, washing with alkali, drying to obtain the isooctyl nitrate, wherein the mass concentration of the sulfuric acid is 70-98%, the mass fraction of the nitric acid is 68-95%, the molar ratio of isooctyl alcohol, nitric acid and sulfuric acid is 1:1.05: 2.5-1: 1.3: 2.6.

wherein, in a mixing channel of the microreactor, the flow speed in the isooctanol channel is converted into 0.3-2.5 m/s; more preferably 0.5 to 2.0 m/s; further preferably 0.75 to 1.5 m/s.

Among them, the operation pressure is preferably 0.1 to 0.4 MPa.

The present invention is described in further detail below with reference to examples, which should be construed as merely illustrative and not a limitation of the scope of the present invention. Furthermore, it should be understood that after reading the teachings of the present invention, one skilled in the art could make various changes or modifications to the present invention and further extend the scope of the invention to the synthesis of similar other nitrates which likewise fall within the scope of the invention as defined in the appended claims.

Example 1

As shown in fig. 1, sulfuric acid, nitric acid and isooctanol are respectively delivered into the microreactors by a first advection pump Al, a second advection pump a2 and a third advection pump A3, wherein the sulfuric acid and the nitric acid are mixed in a first-stage microreactor 21, a mixed acid solution and the isooctanol are mixed and react in a second-stage microreactor 22, and the first-stage microreactor dispersion medium and the second-stage microreactor dispersion medium are both 1.0mm micro narrow slit membranes and 2mm single channels 1 mm. Isooctyl alcohol: nitric acid: the molar ratio of the sulfuric acid is 1:1.05:2.5, the flow velocity in an isooctanol channel is 1.0m/s, the feeding amount is 120ml/min, 55.1ml/min and 103ml/min respectively, the mass fraction of the isooctanol is 98%, the mass fraction of the nitric acid is 68%, the mass fraction of the sulfuric acid is 98%, the reaction temperature is 20 ℃, the diameter of a heat exchange module channel is 8mm x 2m, and the pump head pressure in the operation process is 0.1-0.2 MPa. The reaction feed liquid flows out of the second-stage micro-reactor and then stands in a phase separation clarifying tank for separationThe crude product was analyzed for composition by gas chromatography after being washed with alkali, washed with water and dried, wherein the content of isooctyl nitrate was 100%. The annual (8000 hours per year) throughput of a single channel is about 1.34 x 10⁵The annual yield of L, isooctyl nitrate is about 64.3 t/a. Compared with the total throughput of 8 channels in CN107935857A of 8L/h, the throughput of the single channel is 1L/h, and the throughput of the single channel in the example is 16 times of that of the single channel.

Example 2

As shown in fig. 1, sulfuric acid, nitric acid and isooctanol are respectively delivered into the microreactors by a first advection pump Al, a second advection pump a2 and a third advection pump A3, wherein the sulfuric acid and the nitric acid are mixed in a first-stage microreactor 21, a mixed acid solution and the isooctanol are mixed and react in a second-stage microreactor 22, and the first-stage microreactor dispersion medium and the second-stage microreactor dispersion medium are both 0.62mm micro narrow slit membranes and 1mm single channels. Isooctyl alcohol: nitric acid: the molar ratio of the sulfuric acid is 1:1.05:2.5, the flow rate in the isooctanol channel is 1.5m/s, the feeding amount is 90ml/min, 41.3ml/min and 77.3ml/min respectively, the mass fraction of the isooctanol is 98%, the mass fraction of the nitric acid is 68%, the mass fraction of the sulfuric acid is 98%, the reaction temperature is 30 ℃, and the diameter of the heat exchange module channel is 3mm x 3 m. And (3) standing the reaction feed liquid after flowing out of the second-stage microreactor in a phase-splitting clarifying tank for phase splitting, and analyzing the components of the crude product by using a gas chromatography after alkaline washing, water washing and drying, wherein the content of isooctyl nitrate is 100%. The annual (8000 hours per year) throughput of a single channel is about 1.0 x 10⁵The annual yield of L, isooctyl nitrate is about 48.3 t/a.

EXAMPLE 3

As shown in fig. 1, sulfuric acid, nitric acid and isooctanol are respectively delivered into the microreactors by a first advection pump Al, a second advection pump a2 and a third advection pump A3, wherein the sulfuric acid and the nitric acid are mixed in a first-stage microreactor 21, a mixed acid solution and the isooctanol are mixed and react in a second-stage microreactor 22, and the first-stage microreactor dispersion medium and the second-stage microreactor dispersion medium are both 1.0mm micro narrow slit membranes and 2mm single channels 1 mm. Isooctyl alcohol: nitric acid: the molar ratio of the sulfuric acid is 1:1.05:2.5, the flow rate of isooctanol is 1.25m/s, the feeding amounts are 150ml/min, 68.9ml/min and 128.8ml/min respectively, wherein the mass fraction of isooctanol is 98%, the mass fraction of nitric acid is 68%, and the mass fraction of sulfuric acid is 98%The fraction was 98%, the reaction temperature was 20 ℃, and the heat exchange module channels were 8mm × 2 m. And (3) standing the reaction feed liquid after flowing out of the second-stage microreactor in a phase-splitting clarifying tank for phase splitting, and analyzing the components of the crude product by using a gas chromatography after alkaline washing, water washing and drying, wherein the content of isooctyl nitrate is 100%. The annual (8000 hours per year) throughput of a single channel is about 1.67 x 10⁵The annual yield of L, isooctyl nitrate is about 80.4 t/a.

Example 4

And amplifying the equipment according to production requirements, wherein the channels are amplified from a single channel to 8 channels. Sulfuric acid, nitric acid and isooctanol are respectively conveyed into the microreactors by a first feeding pump Al, a second micro-feeding pump A2 and a third feeding pump A3, wherein the sulfuric acid and the nitric acid are mixed in a first-stage microreactor 21, mixed acid and isooctanol are mixed and react in a second-stage microreactor 22, dispersion media of the first-stage microreactor and the second-stage microreactor are narrow slit membranes, and 8 channels with 2mm x 2mm are arranged. The reactant channels in the heat exchange modules were 5mm by 8 m. Isooctyl alcohol: nitric acid: the molar ratio of sulfuric acid is 1:1.05:2.5, the flow velocity in the isooctanol channel is 0.5m/s, wherein the mass fraction of isooctanol is 98%, the mass fraction of nitric acid is 68%, and the mass fraction of sulfuric acid is 98%. The pump head pressure is 0.1-0.2Mpa in the operation process. And (3) standing the reaction feed liquid after flowing out of the second-stage microreactor in a phase-splitting clarifying tank for phase splitting, and analyzing the components of the crude product by using a gas chromatography after alkaline washing, water washing and drying, wherein the content of isooctyl nitrate is 99.99%. The annual (8000 hours per year) throughput of a single channel is about 1.1 x 10⁶The annual yield of L, isooctyl nitrate is about 515 t/a.

Example 5

And amplifying the equipment according to production requirements, wherein the channels are amplified from a single channel to 8 channels. Sulfuric acid, nitric acid and isooctanol are respectively conveyed into the microreactors by a first feeding pump Al, a second micro-feeding pump A2 and a third feeding pump A3, wherein the sulfuric acid and the nitric acid are mixed in a first-stage microreactor 21, mixed acid and isooctanol are mixed and react in a second-stage microreactor 22, dispersion media of the first-stage microreactor and the second-stage microreactor are narrow slit membranes, and 8 channels with 2mm x 2mm are arranged. The reactant channels in the heat exchange modules were 5mm by 8 m. Isooctyl alcohol: nitric acid: the molar ratio of the sulfuric acid is 1:1.05:2.5, and the conversion is isooctanol channelThe internal flow rate was 1.0m/s, wherein the mass fraction of isooctanol was 98%, the mass fraction of nitric acid was 68%, and the mass fraction of sulfuric acid was 98%. The pump head pressure is 0.2-0.4Mpa in the operation process. And (3) standing the reaction feed liquid after flowing out of the second-stage microreactor in a phase-splitting clarifying tank for phase splitting, and analyzing the components of the crude product by using a gas chromatography after alkaline washing, water washing and drying, wherein the content of isooctyl nitrate is 99.96%. The annual (8000 hours per year) throughput of a single channel is about 2.14 x 10⁶The annual yield of L, isooctyl nitrate is about 1029 t/a.

Example 6

As shown in fig. 1, sulfuric acid, nitric acid and isooctanol are respectively delivered into the microreactors by a first advection pump Al, a second advection pump a2 and a third advection pump A3, wherein the sulfuric acid and the nitric acid are mixed in a first-stage microreactor 21, a mixed acid solution and the isooctanol are mixed and react in a second-stage microreactor 22, and dispersing media of the first-stage microreactor and the second-stage microreactor are both stainless steel microporous membranes of 10 micrometers and 2 × 1 single channels. Isooctyl alcohol: nitric acid: the molar ratio of the sulfuric acid is 1:1.05:2.5, the feeding amounts are 120ml/min, 55.1ml/min and 103ml/min respectively, wherein the mass fraction of isooctanol is 98 percent, the mass fraction of nitric acid is 68 percent, the mass fraction of sulfuric acid is 98 percent, the reaction temperature is 20 ℃, and the heat exchange module channel is 3mm by 3 m. And (3) standing the reaction feed liquid after flowing out of the second-stage microreactor in a phase-splitting clarifying tank for phase splitting, and analyzing the components of the crude product by using a gas chromatography after alkaline washing, water washing and drying, wherein the content of isooctyl nitrate is 100%. The annual (8000 hours per year) throughput of a single channel is about 1.34 x 10⁵The annual yield of L, isooctyl nitrate is about 64.3 t/a.

Example 7

As shown in fig. 1, sulfuric acid, nitric acid and isooctanol are respectively delivered into the microreactors by a first advection pump Al, a second advection pump a2 and a third advection pump A3, wherein the sulfuric acid and the nitric acid are mixed in a first-stage microreactor 21, a mixed acid solution and the isooctanol are mixed and react in a second-stage microreactor 22, and the first-stage microreactor dispersion medium and the second-stage microreactor dispersion medium are both stainless steel single-pore membranes with 0.22mm and 2mm by 1mm single channels. Isooctyl alcohol: nitric acid: the molar ratio of the sulfuric acid is 1:1.05:2.5, the feeding amounts are 120ml/min, 51.6ml/min and 113.55ml/min respectively, wherein the mass fraction of isooctyl alcohol is 98 percent,95 percent of nitric acid, 75 percent of sulfuric acid, 30 ℃ of reaction temperature and 3mm by 3m of heat exchange module channels. And (3) standing the reaction feed liquid after flowing out of the second-stage microreactor in a phase-splitting clarifying tank for phase splitting, and analyzing the components of the crude product by using a gas chromatography after alkaline washing, water washing and drying, wherein the content of isooctyl nitrate is 100%. The annual (8000 hours per year) throughput of a single channel is about 1.36 x 10⁵The annual yield of L, isooctyl nitrate is about 64.3 t/a.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims (10)

1. A high flux low operation pressure micro-reaction equipment for preparing isooctyl nitrate is characterized in that: the equipment comprises a feeding device, a two-stage micro-reaction device and a split-phase clarification device, wherein the feeding device is communicated with the two-stage micro-reaction device, the micro-reaction device is communicated with the split-phase clarification device, sulfuric acid and nitric acid are mixed into mixed acid in the two-stage micro-reaction device, and isooctanol and mixed acid solution react to generate a product.

2. The apparatus of claim 1, wherein the apparatus comprises: the two-stage micro-reaction device comprises a first-stage micro-reactor and a second-stage micro-reactor which are connected in sequence; the discharge port of the first-stage micro-reactor is communicated with the continuous phase inlet of the second-stage micro-reactor, and the discharge port of the second-stage micro-reactor is communicated with the phase-splitting clarifying device.

3. The apparatus of claim 2, wherein the apparatus comprises: the micro-reactor contains a dispersion mixing module.

4. The apparatus of claim 3, wherein the apparatus comprises: the micro-reactor is also provided with a heat transfer module.

5. The apparatus of claim 3, wherein the apparatus comprises: the primary micro-reactor and the secondary micro-reactor have the same structure and respectively comprise an upper membrane device component, a lower membrane device component, a middle two-layer gasket and a dispersion medium; wherein, the dispersion medium is positioned between two layers of gaskets, and the upper membrane device component is a dispersion phase membrane device component and is provided with a dispersion phase inlet; the lower membrane element is a continuous phase membrane element and is provided with a continuous phase inlet and a material outlet.

6. The apparatus of claim 4, wherein the apparatus comprises: wherein the heat transfer module transfers heat for the microchannel.

7. The apparatus of claim 6, wherein the apparatus comprises: the equivalent diameter of the channel is 0.5-10 mm.

8. The apparatus of claim 7 for preparing high throughput and low operating pressure micro-reaction for isooctyl nitrate, wherein: the equivalent diameter of the channel is 0.5-3 mm.

9. The apparatus of claim 5, wherein the apparatus comprises: the dispersion medium comprises a microporous membrane, a micromesh and a micro-slit membrane.

10. The apparatus of claim 9 for preparing high throughput low operating pressure micro-reaction for isooctyl nitrate characterized by: the micro narrow slit film is a flat-plate-shaped micro narrow slit film, and the width of the micro narrow slit film is 0.6-1.0 mm; the pore diameter of the microporous membrane is 1-100 microns, the pore diameter of the microporous membrane is 50-600 microns, and the pressure difference is used as a driving force to realize the micronization of the dispersed phase.

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