Method for industrially preparing acrolein

Abstract

The present invention relates to the field of acrolein preparation, particularly to an industrial acrolein preparation method, which is performed in skid-mounted acrolein production equipment, and comprises: S1, mixing glycerol and an ionic liquid catalyst in a mixer (3) to obtain a mixed raw material, s2, the mixed raw materials are introduced into a reaction medium in a reaction container (10) through a metering pump (4) to be subjected to a dehydration reaction, an acrolein product is generated, and the acrolein product is collected and stored through an acrolein collector (12). The method provided by the invention is carried out in skid-mounted acrolein production equipment, parameters in the preparation process are easy to control, the acrolein production efficiency is high, acrolein can be produced on an oil field in which sewage needs to be treated, and the acrolein can be used while being produced; the technical problem that acrolein is difficult to be applied to oil field sewage treatment due to extremely unstable properties and difficulty in storage and transportation is solved, and industrial application of acrolein in the field of oil field sewage treatment can be realized.

Description

Technical Field

[0001] The invention relates to the field of acrolein preparation, and in particular to a method for industrially preparing acrolein. Background Art

[0002] After long-term use, oil wells have serious scaling and corrosion problems, serious reduction in oil recovery efficiency, and water injection problems caused by sulfides and bacteria during water injection or secondary oil recovery in oil fields to improve water quality and secondary oil recovery. Biocides are used in oil fields to prevent high-speed bacterial reproduction. Commonly used chemical agents include glutaraldehyde, quaternary ammonium, and thiophosphate (THPS). The basic goal of biocides is to prevent fixed bacteria from approaching and penetrating the protective layer of the biofilm. In general, chemical biocides can achieve this effect. Quaternary ammonium substances are most effective in penetrating EPS, which surrounds the fixed biofilm. However, the characteristics of quaternary ammonium surfactants cause a decrease in production when treating injection wells, and a reduction in product in water injection filters, which limits their use in water flooding. When higher concentrations of surfactants are required to control bacteria, it may cause damage to the formation.

[0003] Acrolein or 2-propenal has been successfully used as a chemical agent to control sessile bacteria in water injection systems. It is a non-corrosive, non-surfactant. Water-soluble biocides exhibit excellent oil solubility and are able to penetrate oil-encapsulated surfaces and biofilms to effectively treat sessile bacteria. The mechanism by which acrolein treats bacteria is by reacting with the sulfonyl and amino groups in proteins, denaturing proteins and enzymes in bacterial cells. Compared with traditional biocides, acrolein is most effective in controlling aerobic bacteria, facultative anaerobic bacteria (GAB), and SRB. Adding acrolein to oilfield water is a good treatment method to improve water quality and solve water injection problems caused by bacteria and sulfides during secondary oil recovery.

[0004] CN103261141A discloses a continuous method for producing acrolein by catalytic dehydration of glycerol or glycerol in the presence of an acid catalyst. The method uses a solid acid catalyst and a fluidized bed reactor process, and needs to prepare acrolein under fluidized gas conditions. The parameters in the preparation process are difficult to control, and the fluidized bed reactor is difficult to move, so it is difficult to achieve industrial application in oil fields.

[0005] Since acrolein has extremely harsh storage conditions and is extremely unstable in nature, it is very difficult to store and transport. Oil fields are generally located in remote areas, especially offshore drilling platforms, which have small spaces and are far away from the mainland. This affects the application of acrolein, a high-efficiency oilfield wastewater treatment agent, in oil fields. Summary of the invention

[0006] The purpose of the present invention is to overcome the technical problem in the prior art that acrolein is difficult to realize industrial application in oilfield wastewater treatment.

[0007] In order to achieve the above-mentioned object, the present invention provides a method for industrially preparing acrolein, which is carried out in a skid-mounted acrolein production device, wherein the skid-mounted acrolein production device comprises a mixer 3, a metering pump 4, a reaction container 10 and an acrolein collector 12 connected in sequence, wherein the mixer 3 comprises a cavity 301 and a flow guide 302 arranged in the cavity 301 and parallel to the ground, and the cavity 301 is provided with a glycerol inlet 304, an ionic liquid catalyst inlet 305 and The setting points of the mixed raw material discharge port 306, the glycerol inlet 304 and the ionic liquid catalyst inlet 305 are higher than the guide member 302, and the setting point of the mixed raw material discharge port 306 is lower than the guide member 302. Each of the guide members 302 is provided with a plurality of corner flow members 303, and the angle α between the corner flow member 303 and the guide member 302 is 10°-60°. The setting direction of the corner flow member 303 is opposite to the flow direction of the material in the mixer 3;

[0008] The method comprises the following steps:

[0009] S1: mixing glycerol and an ionic liquid catalyst in the mixer 3 to obtain a mixed raw material, wherein the ionic liquid catalyst comprises a pyridine ionic liquid and an imidazole ionic liquid, and in the ionic liquid catalyst, the weight ratio of the pyridine ionic liquid to the imidazole ionic liquid is 1:1-5, and the mixing weight ratio of the glycerol to the ionic liquid catalyst is 1:0.01-0.05;

[0010] S2: The mixed raw material is introduced into the reaction medium in the reaction container 10 by the metering pump 4 for dehydration reaction to generate an acrolein product, and the acrolein product is collected and stored by the acrolein collector 12, wherein the introduction rate of the mixed raw material is 0.5 g / min to 50 g / min per 1 kg of the reaction medium.

[0011] The method provided by the present invention is carried out in a skid-mounted acrolein production device, and acrolein can be prepared without the presence of fluidized gas. Parameters in the preparation process are easy to control, and the acrolein production efficiency is high. Acrolein can be produced on-site in an oil field where sewage needs to be treated, and the acrolein can be used immediately after production. In addition, the skid-mounted acrolein production device has a simple structure, is easy to assemble and transport, and can repeatedly prepare acrolein in different oil fields, thus solving the technical problem that acrolein is difficult to apply to oilfield sewage treatment due to its extremely unstable properties and difficulty in storage and transportation, and can realize the industrial application of acrolein in the field of oilfield sewage treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the overall connection of a skid-mounted acrolein production equipment provided by the present invention according to a preferred embodiment;

[0013] Figure 2 is a front view of the internal structure of the mixer 3 provided in Example 1 of the present invention;

[0014] Figure 3 is a top view of the internal structure of the mixer 3 provided in Example 1 of the present invention;

[0015] Figure 4 It is a left view of the internal structure of the mixer 3 provided in Example 1 of the present invention;

[0016] Figure 5 is a structural schematic diagram of an automatic cleaning system provided by the present invention according to a preferred embodiment;

[0017] Figure 6 It is a front view of the internal structure of the mixer 3 provided in Comparative Example 1 of the present invention.

[0018] Description of Reference Numerals

[0019] 1. Glycerol storage; 2. Ionic liquid catalyst storage; 3. Mixer; 4. Metering pump; 5. Preheater; 6. Automatic cleaning system; 7. Temperature sensor; 8. Stirring element; 9. Pressure sensor; 10. Reaction vessel; 11. Condenser; 12. Acrolein collector; 13. Heating element; 14. Circulation pump; 15. Filter; 16. Heating jacket; 17. Control system; 18. Vent valve; 19. Check valve;

[0020] 301, cavity; 302, flow guide; 303, corner flow piece; 304, propylene glycol inlet; 305, ionic liquid catalyst inlet; 306, mixed raw material outlet. DETAILED DESCRIPTION

[0021] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0022] As mentioned above, the present invention provides a method for industrially preparing acrolein, which is carried out in a skid-mounted acrolein production device, such as Figure 1 As shown, the skid-mounted acrolein production equipment comprises a mixer 3, a metering pump 4, a reaction vessel 10 and an acrolein collector 12 connected in sequence, wherein Figure 2 As shown, the mixer 3 includes a cavity 301 and a guide member 302 arranged in the cavity 301 and parallel to the ground. The cavity 301 is provided with a glycerol inlet 304, an ionic liquid catalyst inlet 305 and a mixed raw material outlet 306. The setting points of the glycerol inlet 304 and the ionic liquid catalyst inlet 305 are higher than the guide member 302, and the setting point of the mixed raw material outlet 306 is lower than the guide member 302. Each of the guide members 302 is provided with a plurality of corner flow members 303. The angle α between the corner flow member 303 and the guide member 302 is 10°-60°. The setting direction of the corner flow member 303 is opposite to the flow direction of the material in the mixer 3.

[0023] The method comprises the following steps:

[0024] S1: mixing glycerol and an ionic liquid catalyst in the mixer 3 to obtain a mixed raw material, wherein the ionic liquid catalyst comprises a pyridine ionic liquid and an imidazole ionic liquid, and in the ionic liquid catalyst, the weight ratio of the pyridine ionic liquid to the imidazole ionic liquid is 1:1-5, and the mixing weight ratio of the glycerol to the ionic liquid catalyst is 1:0.01-0.05;

[0025] S2: The mixed raw material is introduced into the reaction medium in the reaction container 10 by the metering pump 4 for dehydration reaction to generate an acrolein product, and the acrolein product is collected and stored by the acrolein collector 12, wherein the introduction rate of the mixed raw material is 0.5 g / min to 50 g / min per 1 kg of reaction medium.

[0026] The method provided by the present invention is carried out in a skid-mounted acrolein production device, and acrolein can be prepared without the presence of fluidized gas. Parameters in the preparation process are easy to control, and the acrolein production efficiency is high. Acrolein can be produced on-site in an oil field where sewage needs to be treated, and the acrolein can be used immediately after production. In addition, the skid-mounted acrolein production device has a simple structure, is easy to assemble and transport, and can repeatedly prepare acrolein in different oil fields, thus solving the technical problem that acrolein is extremely unstable in nature, difficult to store and transport, and thus difficult to be used in oilfield sewage treatment.

[0027] According to some preferred embodiments of the present invention, the pyridine ionic liquid is selected from at least one of N-butylpyridine hydrogen sulfate, N-propyl pyridine sulfonate hydrogen sulfate, N-butylpyridine hydrogen phosphate, and propanesulfonic acid pyridine phosphate; the imidazole ionic liquid is selected from at least one of methyl imidazole chloride, methyl butyl imidazole sulfate, methyl propanesulfonic acid imidazole sulfate, and methyl propanesulfonic acid imidazole phosphate. Under this preferred condition, the yield and purity of the acrolein product are higher.

[0028] For example, the structure of the N-butylpyridine hydrogen phosphate is shown in Formula I, the structure of the propanesulfonic acid pyridine phosphate is shown in Formula II, the structure of the methylpropanesulfonic acid imidazole sulfate is shown in Formula III, and the structure of the methylpropanesulfonic acid imidazole phosphate is shown in Formula IV:

[0029]

[0030]

[0031] According to a particularly preferred embodiment of the present invention, the ionic liquid catalyst is a mixture of the N-butylpyridinium hydrogen sulfate and the methylimidazole chloride. More preferably, in the ionic liquid catalyst, the weight ratio of the N-butylpyridinium hydrogen sulfate to the methylimidazole chloride is 1:2-4. Under this preferred condition, the yield and purity of the acrolein product are higher.

[0032] According to a particularly preferred embodiment of the present invention, the ionic liquid catalyst is a mixture of the N-propyl pyridinium sulfonate hydrogen sulfate and the methyl butyl imidazole sulfate. More preferably, in the ionic liquid catalyst, the weight ratio of the N-propyl pyridinium sulfonate hydrogen sulfate and the methyl butyl imidazole sulfate is 1:1.5-3. Under this preferred condition, the yield and purity of the acrolein product are higher.

[0033] According to some preferred embodiments of the present invention, the reaction medium is at least one of heat transfer oil, triphenyl phosphate, tert-butylbenzene diphenyl phosphate, and triisobutylphenyl phosphate. This preferred reaction medium is cheap and readily available, and can provide milder and more stable reaction conditions for the dehydration reaction of glycerol to acrolein.

[0034] According to some preferred embodiments of the present invention, the reaction temperature of the dehydration reaction is 280° C.-310° C., and the reaction pressure is 0-0.1 MPa. Under the preferred conditions, the generation rate of by-products is lower and the yield of acrolein is higher.

[0035] According to some preferred embodiments of the present invention, Figure 2 As shown, the height of the cavity 301 is h, and the distance between the guide member 302 and the bottom of the cavity 301 is h / 6-2h / 3. Under this preferred condition, the purity of the acrolein product is higher.

[0036] According to some preferred embodiments of the present invention, the cavity 301 is cylindrical. Figure 3 As shown, the cross-sectional radius of the cavity 301 is r, and the distance between the guide member 302 and the cross-sectional center of the cavity 301 is not greater than 2r / 3. Under this preferred condition, the purity of the acrolein product is higher.

[0037] According to some preferred embodiments of the present invention, Figure 2 , Figure 3 As shown, the guide member 302 is a rotating guide member. When glycerol and the ionic liquid catalyst are injected into the mixer 3, the guide member 302 in the mixer 3 automatically rotates, driving the corner flow member 303 on the guide member 302 to rotate. Under this preferred condition, the purity of the acrolein product is higher.

[0038] According to some preferred embodiments of the present invention, the rotation rate of the guide member 302 is 4 r / min-10 r / min. Under this preferred condition, the yield and purity of the acrolein product are higher.

[0039] According to some preferred embodiments of the present invention, the corner flow piece 303 is at least one of a butterfly-shaped corner flow piece, a fan-shaped corner flow piece, a triangle-shaped corner flow piece, and a square-shaped corner flow piece.

[0040] According to some particularly preferred embodiments of the present invention, Figure 3 , Figure 4 As shown, the corner flow piece 303 is a butterfly-shaped corner flow piece. Under this preferred condition, the purity of the acrolein product is higher.

[0041] According to some preferred embodiments of the present invention, Figure 1 As shown, in the skid-mounted acrolein production equipment, a preheater 5 is further connected between the metering pump 4 and the reaction container 10, and a heating source is provided inside or outside the preheater 5, and the heating source is used to heat the preheater 5; the method further includes: introducing the mixed raw material into the preheater 5 through the metering pump 4 for preheating treatment, and then introducing the mixed raw material into the reaction medium in the reaction container 10 for dehydration reaction. Under this preferred condition, the generation of by-products can be effectively reduced, and the yield and purity of acrolein can be further improved.

[0042] According to some particularly preferred embodiments of the present invention, the temperature of the preheating treatment is 150° C.-200° C., and the pressure of the preheating treatment is 0-0.1 MPa.

[0043] According to some particularly preferred embodiments of the present invention, a heating jacket 16 is provided on the outer side of the preheater 5, and the heating jacket 16 is used to heat the preheater 5 to provide the temperature conditions required for the preheating treatment.

[0044] According to some preferred embodiments of the present invention, Figure 1As shown, in the skid-mounted acrolein production equipment, a condenser 11 is further connected between the reaction container 10 and the acrolein collector 12; the method further comprises: the acrolein product is condensed by the condenser 11 and then collected and stored by the acrolein collector 12. Under this preferred condition, the collection of the acrolein product can be made more convenient.

[0045] According to some particularly preferred embodiments of the present invention, the temperature of the condensation treatment is -4°C to 5°C.

[0046] According to some particularly preferred specific embodiments of the present invention, the condenser 11 is any one of a straight tube condenser, a coil condenser, a shell and tube condenser, and a plate condenser.

[0047] According to some preferred embodiments of the present invention, Figure 5 As shown, the skid-mounted acrolein production equipment is also provided with an automatic cleaning system 6, which includes a circulation pump 14 and a filter 15. One end of the circulation pump 14 is connected to the filter 15, and the other end is connected to the bottom of the reaction vessel 10. The other end of the filter 15 connected to the circulation pump 14 is connected to the upper part of the reaction vessel 10. When the automatic cleaning system 6 is working, the mixed material in the reaction vessel 10 flows through the filter 15 through the circulation pump 14, and after the solid particle by-products are filtered out by the filter 15, the remaining filtrate is recycled back to the reaction vessel 10. Under this preferred condition, the by-products in the reaction medium can be effectively removed, and the continuous working time of the skid-mounted acrolein production equipment can be greatly extended.

[0048] According to some preferred embodiments of the present invention, Figure 1 As shown, the skid-mounted acrolein production equipment further includes a glycerol storage 1 and an ionic liquid catalyst storage 2. The glycerol storage 1 is communicated with the glycerol inlet 304 of the mixer 3, and the ionic liquid catalyst storage 2 is communicated with the ionic liquid catalyst inlet 305 of the mixer 3. The glycerol storage 1 is used to store glycerol and provide glycerol to the mixer 3; the ionic liquid catalyst storage 2 is used to store glycerol and provide ionic liquid catalyst to the mixer 3.

[0049] According to some preferred embodiments of the present invention, the reaction container 10 is further provided with at least one of a heating element 13 , a temperature sensor 7 , a pressure sensor 9 , and a stirring element 8 .

[0050] According to some particularly preferred embodiments of the present invention, Figure 1As shown, the heating element 13 is disposed at the bottom of the reaction container 10 and is used to heat the mixed material in the reaction container 10 to provide the required temperature conditions for the dehydration reaction.

[0051] According to some particularly preferred embodiments of the present invention, Figure 1 As shown, the temperature measuring component of the temperature sensor 7 is arranged at the lower part of the reaction vessel 10. When the skid-mounted acrolein production equipment is working normally, the temperature measuring component of the temperature sensor 7 is located below the liquid level of the reaction medium in the reaction vessel 10. The temperature sensor 7 is used to monitor the temperature of the reaction medium or mixed material in the reaction vessel 10.

[0052] According to some particularly preferred embodiments of the present invention, Figure 1 As shown, the pressure sensor 9 is arranged at the upper part of the reaction container. When the skid-mounted acrolein production equipment is working normally, the pressure measuring piece of the pressure sensor 9 is located above the liquid level of the reaction medium in the reaction container 10. The pressure sensor 9 is used to monitor the air pressure in the reaction container 10.

[0053] According to some particularly preferred embodiments of the present invention, Figure 1 As shown, the reaction container 10 is further provided with a stirring member 8, and the stirring member 8 is used to stir the mixed material in the reaction container 10 so that the dehydration reaction proceeds more fully.

[0054] According to some particularly preferred specific embodiments of the present invention, the stirring element 8 is any one of a plowshare stirring element, a spiral ribbon stirring element, a paddle stirring element, and a double-shaft paddle stirring element.

[0055] According to some preferred embodiments of the present invention, the acrolein collector 12 is further provided with a vent valve 18 , and the vent valve 18 is used to vent impurity gases collected by collecting acrolein to balance the gas pressure in the acrolein collector 12 .

[0056] According to some preferred embodiments of the present invention, the feed port of the reaction vessel 10 is arranged at the bottom of the reaction vessel 10, and the feed port is used to introduce the mixed raw materials into the reaction vessel 10. A check valve 19 is provided at the feed port, and the check valve 19 is used to prevent the mixed raw materials transported to the reaction vessel 10 from flowing back.

[0057] According to some particularly preferred embodiments of the present invention, the check valve 19 is any one of a butterfly check valve, a lift check valve, and a swing check valve.

[0058] According to some preferred embodiments of the present invention, the skid-mounted acrolein production equipment also includes a control system 17, and the control system 17 is connected to the glycerol storage 1, the ionic liquid catalyst storage 2, the mixer 3, the metering pump 4, the preheater 5, the automatic cleaning system 6, the temperature sensor 7, the stirring element 8, the pressure sensor 9, the reaction vessel 10, the condenser 11, the acrolein collector 12, the heating element 13, the circulating pump 14, the filter 15, the heating jacket 16, the vent valve 18, and the check valve 19 through wired or wireless connection, and the control system 17 is used to control the normal operation of the skid-mounted acrolein production equipment.

[0059] The present invention will be described in detail below by way of examples. In the following examples:

[0060] Ionic liquid catalyst I: a mixture of N-butylpyridinium hydrogen sulfate and methylimidazole chloride in a weight ratio of 1:3, wherein N-butylpyridinium hydrogen sulfate was purchased from Beijing Huawei Ruike Chemical Co., Ltd. with a brand name of HWG16703; methylimidazole chloride was purchased from Tianjin Xiens Biochemical Technology Co., Ltd. with a brand name of A-24589;

[0061] Ionic liquid catalyst II: a mixture of N-propyl sulfonate pyridinium hydrogen sulfate and methyl butyl imidazole sulfate in a weight ratio of 1:2, wherein N-propyl sulfonate pyridinium hydrogen sulfate was purchased from Beijing Huawei Ruike Chemical Co., Ltd. with a brand name of HWG1921; methyl butyl imidazole sulfate was purchased from Zhengzhou Deyuankai Chemical Co., Ltd. with a purity of 98%;

[0062] Reaction medium: thermal oil L-QD350, Shenyang Snow Lion Chemical Products Co., Ltd.;

[0063] Glycerol, purity 99wt%.

[0064] Example 1

[0065] The skid-mounted acrolein production equipment includes:

[0066] The invention comprises a mixer 3, a metering pump 4, a reaction container 10 and an acrolein collector 12 connected in sequence, wherein the mixer 3 comprises a cavity 301 and a guide member 302 arranged in the cavity 301 and parallel to the ground, the cavity 301 is provided with a glycerol inlet 304, an ionic liquid catalyst inlet 305 and a mixed raw material outlet 306, the glycerol inlet 304 and the ionic liquid catalyst inlet 305 are set at higher points than the guide member 302, the mixed raw material outlet 306 is set at a lower point than the guide member 302, and the number of the guide members 302 is 3, as shown in FIG. Figure 3 , Figure 4As shown, they are respectively the first flow guide, the second flow guide and the third flow guide, the first flow guide is arranged in the cavity 301 at a distance of h / 2 from the bottom and 0 from the center of the cross section, the second flow guide and the third flow guide are respectively arranged on both sides of the first flow guide, the second flow guide and the third flow guide are respectively arranged in the cavity 301 at a distance of h / 4 from the bottom and r / 3 from the center of the cross section, and the first flow guide, the second flow guide and the third flow guide are parallel to each other, each of the flow guides 302 is provided with 5 corner flow members 303, the angle α between the corner flow member 303 and the flow guide 302 is 25°, and the setting direction of the corner flow member 303 is opposite to the flow direction of the material in the mixer 3;

[0067] The skid-mounted acrolein production equipment further includes a glycerol storage 1 and an ionic liquid catalyst storage 2, wherein the glycerol storage 1 is connected to the glycerol inlet 304 of the mixer 3, and the ionic liquid catalyst storage 2 is connected to the ionic liquid catalyst inlet 305 of the mixer 3;

[0068] In the skid-mounted acrolein production equipment, a preheater 5 is also connected between the metering pump 4 and the reaction container 10, and a heating jacket 16 is provided on the outer side of the preheater 5;

[0069] The skid-mounted acrolein production equipment is also provided with an automatic cleaning system 6, which includes a circulation pump 14 and a filter 15, one end of the circulation pump 14 is connected to the filter 15, and the other end is connected to the bottom of the reaction container 10, and the other end of the filter 15 connected to the circulation pump 14 is connected to the upper part of the reaction container 10;

[0070] In the skid-mounted acrolein production equipment, a condenser 11 is also connected between the reaction container 10 and the acrolein collector 12;

[0071] The reaction container 10 is also provided with a heating element 13, a temperature sensor 7, a pressure sensor 9 and a stirring element 8;

[0072] The skid-mounted acrolein production equipment further includes a control system 17, and the control system 17 is used to control the operation of the skid-mounted acrolein production equipment.

[0073] Method for preparing acrolein:

[0074] S1: introducing glycerol in the glycerol storage 1 and the ionic liquid catalyst in the ionic liquid catalyst storage 2 into the mixer 3 to mix to obtain a mixed raw material; the rotation rate of the guide member 302 in the mixer 3 is 5 r / min;

[0075] S2: The mixed raw material is introduced into the preheater 5 for preheating through the metering pump 4, and then introduced into the reaction medium in the reaction vessel 10 for dehydration reaction to generate a gaseous acrolein product. The gaseous acrolein product is condensed by the condenser 11 and then collected and stored by the acrolein collector 12; wherein the amount of reaction medium in the reaction vessel 10 is 10 kg, and the stirring rate of the stirring element in the reaction vessel 10 is 8 r / min;.

[0076] During the process of step S1 and step S2 , the automatic cleaning system 6 cleans the mixed material in the reaction container 10 .

[0077] Specifically, various parameters in the preparation process are shown in Table 1 below.

[0078] Example 2

[0079] The skid-mounted acrolein production equipment is the same as that in Example 1;

[0080] The method for preparing acrolein is similar to that of Example 1, except that the type and amount of the ionic liquid catalyst and the feed rate of the mixed raw material are changed. Specifically, the parameters in the preparation process are shown in Table 1 below.

[0081] Example 3

[0082] The skid-mounted acrolein production equipment refers to Example 1, except that the skid-mounted acrolein production equipment does not include a preheater 5 and an automatic cleaning system 6, and no preheating treatment and reaction medium cleaning treatment are performed during the preparation of acrolein. Specifically, the skid-mounted acrolein production equipment includes:

[0083] The skid-mounted acrolein production equipment includes:

[0084] The invention comprises a mixer 3, a metering pump 4, a reaction vessel 10 and an acrolein collector 12 connected in sequence, wherein: Figure 2 As shown, the mixer 3 includes a cavity 301 and a guide member 302 arranged in the cavity 301 and parallel to the ground. The cavity 301 is provided with a glycerol inlet 304, an ionic liquid catalyst inlet 305 and a mixed raw material outlet 306. The setting points of the glycerol inlet 304 and the ionic liquid catalyst inlet 305 are higher than the guide member 302, and the setting point of the mixed raw material outlet 306 is lower than the guide member 302. The number of the guide members 302 is 3, as shown in FIG. Figure 3 , Figure 4As shown, they are respectively the first flow guide, the second flow guide and the third flow guide, the first flow guide is arranged in the cavity 301 at a distance of h / 2 from the bottom and passing through the center of the cross section, the second flow guide and the third flow guide are respectively arranged on both sides of the first flow guide, the second flow guide and the third flow guide are respectively arranged in the cavity 301 at a distance of h / 4 from the bottom and r / 3 from the center of the cross section, and the first flow guide, the second flow guide and the third flow guide are parallel to each other, each of the flow guides 302 is provided with 5 corner flow members 303, the angle α between the corner flow member 303 and the flow guide 302 is 25°, and the setting direction of the corner flow member 303 is opposite to the flow direction of the material in the mixer 3;

[0085] The skid-mounted acrolein production equipment further includes a glycerol storage 1 and an ionic liquid catalyst storage 2, wherein the glycerol storage 1 is connected to the glycerol inlet 304 of the mixer 3, and the ionic liquid catalyst storage 2 is connected to the ionic liquid catalyst inlet 305 of the mixer 3;

[0086] In the skid-mounted acrolein production equipment, a condenser 11 is also connected between the reaction container 10 and the acrolein collector 12;

[0087] The reaction container 10 is also provided with a heating element 13, a temperature sensor 7, a pressure sensor 9 and a stirring element 8;

[0088] The skid-mounted acrolein production equipment further includes a control system 17, and the control system 17 is used to control the operation of the skid-mounted acrolein production equipment.

[0089] Method for preparing acrolein:

[0090] S1: introducing glycerol in the glycerol storage 1 and the ionic liquid catalyst in the ionic liquid catalyst storage 2 into the mixer 3 to mix to obtain a mixed raw material; the rotation rate of the guide member 302 in the mixer 3 is 5 r / min;

[0091] S2: The mixed raw material is introduced into the reaction medium in the reaction container 10 by the metering pump 4 for dehydration reaction to generate a gaseous acrolein product. The gaseous acrolein product is condensed by the condenser 11 and then collected and stored by the acrolein collector 12; wherein the amount of reaction medium in the reaction container 10 is 10 kg, and the stirring rate of the stirring element in the reaction container 10 is 8 r / min.

[0092] Specifically, various parameters in the preparation process are shown in Table 1 below.

[0093] Comparative Example 1

[0094] The skid-mounted acrolein production equipment refers to Example 3, except that the mixer 3 in the skid-mounted acrolein production equipment does not have a flow guide 302 and a corner flow member 303. Specifically, the skid-mounted acrolein production equipment includes:

[0095] The invention comprises a mixer 3, a metering pump 4, a reaction vessel 10 and an acrolein collector 12 connected in sequence, wherein: Figure 6 As shown, the mixer 3 includes a cavity 301, and the cavity 301 is provided with a glycerol inlet 304, an ionic liquid catalyst inlet 305 and a mixed raw material outlet 306.

[0096] The skid-mounted acrolein production equipment further includes a glycerol storage 1 and an ionic liquid catalyst storage 2, wherein the glycerol storage 1 is connected to the glycerol inlet 304 of the mixer 3, and the ionic liquid catalyst storage 2 is connected to the ionic liquid catalyst inlet 305 of the mixer 3;

[0097] In the skid-mounted acrolein production equipment, a condenser 11 is also connected between the reaction container 10 and the acrolein collector 12;

[0098] The reaction container 10 is also provided with a heating element 13, a temperature sensor 7, a pressure sensor 9 and a stirring element 8;

[0099] The skid-mounted acrolein production equipment further includes a control system 17, and the control system 17 is used to control the operation of the skid-mounted acrolein production equipment.

[0100] Method for preparing acrolein:

[0101] S1: introducing glycerol in the glycerol storage tank 1 and the ionic liquid catalyst in the ionic liquid catalyst storage tank 2 into the mixer 3 and mixing them to obtain a mixed raw material;

[0102] S2: The mixed raw materials are introduced into the reaction vessel 10 through the metering pump 4 for dehydration reaction to generate a gaseous acrolein product. The gaseous acrolein product is condensed by the condenser 11 and then collected and stored by the acrolein collector 12; wherein the stirring rate of the stirring element in the reaction vessel 10 is 8r / min.

[0103] It should be noted that there is no reaction medium in the reaction container 10 of this comparative example, and specific parameters such as the type of ionic liquid catalyst and the introduction rate of the mixed raw materials are shown in Table 1 below.

[0104] Table 1

[0105]

[0106]

[0107] Note:

[0108] V1 represents the rate at which the mixed raw materials are introduced into the reaction vessel 10;

[0109] V2 represents the rate at which acrolein product is collected in the acrolein collector 12;

[0110] The cleaning process refers to the filtering and impurity removal process performed by the automatic cleaning system 6 on the mixed material in the reaction container 10 during the preparation process;

[0111] Acrolein purity means the purity of acrolein in the acrolein product collected in the acrolein collector 12;

[0112] The continuous operation limit indicates the time that the skid-mounted acrolein production equipment can continuously operate under this condition. It should be noted that: since some by-products are produced in the process of preparing acrolein, excessive accumulation of by-products will affect the normal progress of the dehydration reaction, and excessive accumulation of by-products will also damage the skid-mounted acrolein production equipment.

[0113] It can be seen from the results in Table 1 that the method provided by the present invention can prepare acrolein without the presence of fluidized gas, the parameters in the preparation process are easy to control, the acrolein production efficiency is high, the purity of the acrolein product is high, the production volume, production rate and production time limit can be adjusted according to actual needs, and acrolein can be produced on-site in an oil field that needs to treat wastewater, and it can be used immediately after production, which solves the technical problem that acrolein is difficult to apply to oilfield wastewater treatment due to its extremely unstable properties and difficulty in storage and transportation, and can realize the industrial application of acrolein in the field of oilfield wastewater treatment.

[0114] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for industrially preparing acrolein, characterized in that: The method is carried out in a skid-mounted acrolein production device, the skid-mounted acrolein production device comprising a mixer (3), a metering pump (4), a reaction container (10) and an acrolein collector (12) connected in sequence, wherein the mixer (3) comprises a cavity (301) and a flow guide (302) arranged in the cavity (301) and parallel to the ground, the cavity (301) is provided with a glycerol inlet (304), an ionic liquid catalyst inlet (305) and a mixed raw material outlet (306), and the The setting points of the glycerol inlet (304) and the ionic liquid catalyst inlet (305) are higher than the guide member (302), and the setting point of the mixed raw material outlet (306) is lower than the guide member (302). Each of the guide members (302) is provided with a plurality of corner flow members (303), and the angle α between the corner flow member (303) and the guide member (302) is 10°-60°. The setting direction of the corner flow member (303) is opposite to the flow direction of the material in the mixer (3); The method comprises the following steps: S1: mixing glycerol and an ionic liquid catalyst in the mixer (3) to obtain a mixed raw material, wherein the ionic liquid catalyst comprises a pyridine ionic liquid and an imidazole ionic liquid, and in the ionic liquid catalyst, the weight ratio of the pyridine ionic liquid to the imidazole ionic liquid is 1:(1-5), and the mixing weight ratio of the glycerol to the ionic liquid catalyst is 1:0.01-0.05; S2: The mixed raw material is introduced into the reaction medium in the reaction container (10) by means of a metering pump (4) for dehydration reaction to generate an acrolein product, and the acrolein product is collected and stored by the acrolein collector (12), wherein the introduction rate of the mixed raw material is 0.5 g / min to 50 g / min per 1 kg of the reaction medium.

2. The method according to claim 1, characterized in that The pyridine ionic liquid is selected from at least one of N-butylpyridine hydrogen sulfate, N-propyl pyridine sulfonate hydrogen sulfate, N-butylpyridine hydrogen phosphate, and propanesulfonic acid pyridine phosphate; The imidazole ionic liquid is selected from at least one of methyl imidazole chloride, methyl butyl imidazole sulfate, methyl propane sulfonic acid imidazole sulfate, and methyl propane sulfonic acid imidazole phosphate.

3. The method according to claim 2, characterized in that The ionic liquid catalyst is a mixture of N-butylpyridinium hydrogen sulfate and methylimidazole chloride, Preferably, in the ionic liquid catalyst, the weight ratio of the N-butylpyridinium hydrogen sulfate to the methylimidazole chloride is 1:(2-4).

4. The method according to claim 2, characterized in that: The ionic liquid catalyst is a mixture of the N-propyl pyridinium sulfonate hydrogen sulfate and the methyl butyl imidazole sulfate; Preferably, in the ionic liquid catalyst, the weight ratio of the N-propyl pyridinium sulfonate to the methyl butyl imidazole sulfate is 1:(1.5-3).

5. The method according to claim 1, characterized in that The reaction medium is at least one of heat transfer oil, triphenyl phosphate, tert-butylbenzene diphenyl phosphate, and triisobutylphenyl phosphate; Preferably, the reaction temperature of the dehydration reaction is 280°C-310°C, and the reaction pressure is 0-0.1Mpa.

6. The method according to claim 1, characterized in that The height of the cavity (301) is h, and the distance between the flow guide (302) and the bottom of the cavity (301) is h / 6-2h / 3; Preferably, the cavity (301) is cylindrical, the cross-sectional radius of the cavity (301) is r, and the distance between the guide member (302) and the center of the cross-sectional circle of the cavity (301) is no more than 2r / 3; More preferably, the flow guide (302) is a rotating flow guide, and the corner flow member (303) is at least one of a butterfly corner flow member, a fan corner flow member, a triangle corner flow member, and a square corner flow member.

7. The method according to any one of claims 1 to 6, characterized in that: In the skid-mounted acrolein production equipment, a preheater (5) is also connected between the metering pump (4) and the reaction container (10); The method further comprises: introducing the mixed raw material into the preheater (5) through a metering pump (4) for preheating, and then introducing the mixed raw material into the reaction medium in the reaction container (10) for dehydration reaction; Preferably, the temperature of the preheating treatment is 150°C-200°C, and the pressure of the preheating treatment is 0-0.1 MPa.

8. The method according to any one of claims 1 to 6, characterized in that: In the skid-mounted acrolein production equipment, a condenser (11) is also connected between the reaction container (10) and the acrolein collector (12); The method further comprises: the acrolein product is condensed by the condenser (11) and then collected and stored by the acrolein collector (12); Preferably, the temperature of the condensation treatment is -4°C to 5°C.

9. The method according to any one of claims 1 to 6, characterized in that: The skid-mounted acrolein production equipment is also provided with an automatic cleaning system (6), which comprises a circulation pump (14) and a filter (15), one end of the circulation pump (14) being connected to the filter (15), and the other end of the circulation pump (14) being connected to the bottom of the reaction container (10), and the other end of the filter (15) being connected to the circulation pump (14) being connected to the upper part of the reaction container (10).

10. The method according to any one of claims 1 to 6, characterized in that: The skid-mounted acrolein production equipment further comprises a glycerol storage device (1) and an ionic liquid catalyst storage device (2), wherein the glycerol storage device (1) is connected to a glycerol inlet port (304) of the mixer (3), and the ionic liquid catalyst storage device (2) is connected to an ionic liquid catalyst inlet port (305) of the mixer (3).

11. The method according to any one of claims 1 to 6, characterized in that: The reaction container (10) is also provided with at least one of a heating element (13), a temperature sensor (7), a pressure sensor (9), and a stirring element (8).

12. The method according to any one of claims 1 to 6, characterized in that: The skid-mounted acrolein production equipment further comprises a control system (17), wherein the control system (17) is used to control the operation of the skid-mounted acrolein production equipment.

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