CN214991232U

CN214991232U - Device for alkylation continuous reaction of m-cresol and/or p-cresol

Info

Publication number: CN214991232U
Application number: CN202121337017.8U
Authority: CN
Inventors: 刘大威
Original assignee: Nanjing Element Technology Co ltd
Current assignee: Nanjing Element Technology Co ltd
Priority date: 2021-06-16
Filing date: 2021-06-16
Publication date: 2021-12-03
Anticipated expiration: 2031-06-16

Abstract

The utility model discloses a device for m-cresol and/or p-cresol alkylation continuous reaction, which couples a tubular reaction module, a tubular reactor water evaporation heat removal circulation module and a reaction rectification module, combines the characteristics of large heat transfer area and high heat transfer coefficient of a tubular reactor unit volume and the advantages of high heat transfer speed and rapid cooling of the water circulation cooling module in the alkylation reaction process, can realize continuous production, has high automation degree, overcomes the bottleneck of poor heat transfer efficiency of the existing alkylation reaction, greatly improves the heat transfer efficiency of the alkylation reaction, can break the restriction of reaction equilibrium state, improves the conversion rate of isobutene, does not need to arrange a top condenser and a tower kettle reboiler in the reaction rectification tower to recycle isobutene, has simple structure and lower equipment investment, stable product quality, low energy consumption and the like, and is particularly suitable for medium-scale and large-scale alkylation reactions.

Description

Device for alkylation continuous reaction of m-cresol and/or p-cresol

Technical Field

The utility model belongs to the technical field of the separation of m-cresol and p-cresol, concretely relates to a device that is used for m-cresol and/or p-cresol alkylation to react in succession.

Background

Cresol is an organic chemical intermediate with wide application, p-cresol is a raw material for preparing antioxidant 2, 6-di-tert-butyl p-cresol and rubber anti-aging agent, cresol-formaldehyde resin and plasticizer can be prepared in the plastic industry, and the cresol-formaldehyde resin and the plasticizer can be used as a disinfectant in medicine and can also be used as raw materials of pesticide and dye; m-cresol is an important raw material for synthesizing organic intermediates, and has important application in color film developers, synthetic resins, adhesives and the like. The boiling points of m-cresol and p-cresol are very close to each other, so that it is difficult to directly separate them by rectification, and when mono-tert-butyl (m/p) -cresol or di-tert-butyl (m/p) -cresol is produced by alkylation of isobutylene, the difference in boiling points of the components becomes large, so that the separation process becomes easy. The isobutene alkylation method is a main process method for separating a m-cresol and p-cresol mixture, and is also a main process method for synthesizing mono-tert-butyl (or p-cresol) and di-tert-butyl (or p-cresol). At present, in China, the m-cresol and p-cresol separation or the tert-butyl (or p-cresol) synthesis mostly adopts an intermittent reaction kettle, the yield is small, the number of operators is large, the energy consumption is high, the efficiency is low, and the safety production control difficulty is high.

Chinese patent CN104496758A discloses a method for continuous reaction of m-cresol and p-cresol alkylation, which adopts 6 alkylation kettles connected in series to carry out continuous reaction of alkylation, and although the reaction device provided in the patent can carry out continuous production, the alkylation reactors adopted in the reaction device are of kettle type, and for the alkylation reaction with larger reaction heat, enough heat exchange area is difficult to provide, the productivity of a single device is limited, the reaction time is long, and the number of devices is large; meanwhile, the alkylation reaction is a reversible reaction, although 6 kettle-type reactors are connected in series, the reaction limit can only be realized until the reaction is in a reaction equilibrium state, and in order to improve the reaction rate in the later period, isobutene is required to be excessive; however, the excess isobutene and the reaction equilibrium are limited, and the unreacted isobutene needs to be added with isobutene recycling equipment to improve the utilization rate of materials.

Chinese patent CN111302904A discloses an alkylation continuous reaction device for BHT production, wherein a tower reactor is adopted in the alkylation reaction process, and the reaction device provided in the patent is difficult to provide enough heat exchange area for alkylation reaction with large reaction heat and the capacity of a single device is limited; meanwhile, the reaction can only be carried out to a reaction equilibrium state at the limit of the reaction, and the utilization rate of materials is improved by adding isobutene recycling equipment due to excessive isobutene and unreacted isobutene limited by the reaction equilibrium.

SUMMERY OF THE UTILITY MODEL

The utility model aims at the separation in the present prior art, to cresol adopt intermittent type formula reation kettle more, in carrying out alkylation reaction process with the isobutene, alkylating agent isobutene can not fully contact with mixed phenol (metacresol and the mixture of constituteing to cresol), isobutene conversion rate is on the low side and heat transfer efficiency hangs down the scheduling problem, a device that is used for metacresol and/or paracresol alkylation continuous reaction is provided, will be listed as tubular reaction module, it withdraws heat cycle module and reaction rectification module to take the coupling to list tubular reactor water evaporation, in alkylation reaction's in-process, it is big that list tubular reactor has unit volume heat transfer area (ordinary kettle reactor unit volume heat transfer area is about 1~8m²The heat transfer area per unit volume of the conventional tubular reactor can reach 70m²Left and right), high heat transfer coefficient (the media on both sides are water and are both liquid phase, the total heat transfer coefficient of the kettle reactor with the stirring and the coil is 700W/m²about/K, the total heat transfer coefficient of the kettle type reactor without stirring and coil pipes is smaller, and the total heat transfer coefficient of the shell and tube type reactor can reach 2000W/m²approximately/K), the tubular reactor uses a water evaporation heat removal circulation module, except that the heat transfer coefficient is high, under the given water evaporation pressure, the evaporation temperature is constant, the reaction temperature distribution in the tubular reactor is more uniform, the heat transfer temperature difference at two sides of the tubular reactor can be changed by adjusting the water evaporation pressure, and further the reaction temperature and the dynamic response of the heat removal control of the reactor can be adjusted and controlledThe method is fast and has good effect. The tubular reaction module and the tubular reactor water evaporation heat removal circulation module are matched for use, so that the requirements of strong exothermic reaction on timely heat removal and local over-high temperature avoidance can be met, the reaction temperature control effect is good, and the production capacity of single equipment is high; the reaction rectification module breaks the equilibrium state limitation of reversible reaction, the reaction rate is high, the reaction selectivity is good, the utilization rate of isobutene raw materials is high, and isobutene recovery facilities do not need to be arranged; the device has the advantages of continuous production, high automation degree, simple structure, improvement on the production efficiency of the whole alkylation reaction, low equipment investment, stable product quality, low energy consumption and the like.

The utility model adopts the technical scheme as follows:

a device for the continuous alkylation reaction of m-cresol and/or p-cresol comprises a tubular reaction module, a tubular reactor water evaporation heat removal circulation module and a reaction rectification module:

the tubular reaction module comprises a preheater, a high-efficiency mixer, a tubular reactor and a pressure stabilizing tank, wherein the preheater is connected with the high-efficiency mixer, the high-efficiency mixer is connected with a feed inlet of the tubular reactor, a discharge outlet of the tubular reactor is connected with the pressure stabilizing tank, and the pressure stabilizing tank is provided with a pressure split regulating system;

the shell and tube reactor water evaporation heat removal circulation module comprises a water vapor condensation cooler, a water vapor condensate tank, a vacuum pump inlet condensation cooler and a vacuum pump, wherein a water vapor outlet of the shell and tube reactor is connected with an inlet of the water vapor condensation cooler, an outlet of the water vapor condensation cooler is connected with an inlet I of the water vapor condensate tank, an outlet I of the steam condensate tank is connected with a water inlet of the shell and tube reactor, an outlet II of the water vapor condensate tank is connected with an inlet of the vacuum pump inlet condensation cooler, an outlet I of the vacuum pump inlet condensation cooler is connected with an inlet II of the water vapor condensate tank, and an outlet II of the vacuum pump inlet condensation cooler is connected with the vacuum pump;

the reactive distillation module comprises a tower feeding vaporizer, reactive distillation tower reaction temperature control equipment and a reactive distillation tower, wherein a pressure stabilizing tank is connected with an inlet of the tower feeding vaporizer, a pressure reducing valve is arranged on a pipeline between the pressure stabilizing tank and the tower feeding vaporizer, a gas-phase discharge port of the tower feeding vaporizer is connected with the lower part of the reactive distillation tower, a liquid-phase discharge port of the tower feeding vaporizer is connected with an inlet of the reactive distillation tower reaction temperature control equipment, an outlet of the reactive distillation tower reaction temperature control equipment is connected with the upper part of the reactive distillation tower, and the reactive distillation tower is sequentially provided with a distillation section, a reaction section and a stripping section from top to bottom.

The number of the tubular reactors can be selected according to actual needs, for example, the number of the tubular reactors is 1 or more according to the limitation requirements of raw materials and products, and the number of the tubular reactors is more than 2, but not limited to 2, 3, 4, 5, 10 or 15. When the number of the tubular reactors is plural, that is, 2 or more, the tubular reactors are connected in series and/or in parallel. Preferably, the number of the tubular reactors is 1-3. For the tubular reactors in series, the isobutene serving as the alkylating agent can be added all before the first tubular reactor or can be added separately, that is, the isobutene is added before each tubular reactor, and when the isobutene is added separately, the isobutene amount at each addition point can be the same or different, and generally the isobutene amount is fed in progressively one tubular reactor after another. For example, when 3 tubular reactors in series are arranged in the apparatus, the liquid phase isobutylene may be fed in three portions, 65% of the total amount being fed before the first tubular reactor, 25% of the total amount being fed before the second tubular reactor, and 10% of the total amount being fed before the third tubular reactor.

In the device, a pressure range regulating system is arranged on the pressure stabilizing tank, and the pressure range regulating system can adopt common pressure control equipment in the prior art and is used for controlling the reaction pressure of the shell and tube reactor.

The number of the high-efficiency mixers can be selected according to actual needs, for example, the number of the high-efficiency mixers is 1, and the number of the high-efficiency mixers can be more than 2, and the high-efficiency mixers can be but are not limited to 2, 3, 4, 5, 10 or 15. Generally, when the number of the tubular reactors is plural, each tubular reactor may be provided with a high-efficiency mixer or other similar equipment for dispersing and uniformly mixing.

The utility model discloses a tubular reactor can select the tubular reactor of the tubular reactor that is commonly used on the market to do not carry out strict restriction to its specification, can carry out homogeneous reaction, also can carry out heterogeneous reaction, for example, liquid-liquid phase reaction or gas-liquid phase reaction. In a preferred embodiment, the tubes or spaces of the shell-and-tube reactor are filled with a catalyst for the alkylation of m-cresol and/or p-cresol with isobutene. As for the catalyst, a homogeneous catalyst can be selected, and a heterogeneous catalyst can be selected according to actual requirements. When the catalyst is heterogeneous solid catalyst, the catalyst can be filled in the tubes of the tubular reactor or among the tubes of the tubular reactor.

At present, isobutene is used as an alkylating agent, m-cresol and/or p-cresol (cresol) is used as a raw material for carrying out alkylation continuous reaction, the reaction temperature is generally lower and is not higher than 100 ℃, for example, the reaction temperature is selected to be 50-90 ℃ when the device is used for carrying out alkylation reaction. For the problem of heat transfer generally existing in the alkylation reaction process due to a large amount of heat release, water cooling is generally adopted, but the temperature difference between the inlet and the outlet of cooling water is limited, the heat transfer coefficient is not high, the heat transfer effect is poor, the temperature in each reaction device (such as a tubular reactor) cannot be quickly reduced to the reaction temperature, and the temperature is too high, so that side reaction is easily carried out, the yield and the purity of products are reduced, and the production efficiency of each reaction device is severely limited.

This device adopts shell and tube reactor water evaporation to remove heat circulation module, except that heat transfer coefficient is high, under given water vapor pressure, evaporating temperature is invariable, the inside reaction temperature distribution of shell and tube reactor is more even, through adjusting water vapor pressure, can change shell and tube reactor both sides heat transfer difference in temperature, and then the regulation and control reaction temperature, the reaction heat that produces in the shell and tube reactor can in time be withdrawn for the reactor removes the dynamic response of heat control fast, effectual. In the alkylation reaction process, a vacuum pump is started to control the pressure in a water evaporation heat removal circulation module to be 7-30 kpa (a), deoxygenated water is introduced into a column type tubular reactor, so that the deoxygenated water entering the column type tubular reactor absorbs heat to carry out negative pressure evaporation, water vapor generated after the negative pressure evaporation enters a water vapor condensation cooler from a steam outlet of the column type tubular reactor to be condensed, condensed water obtained after the condensation enters a water vapor condensed liquid tank, and the condensed water in the water vapor condensed liquid tank continues to absorb heat to carry out the negative pressure evaporation after entering the column type tubular reactor. Because the temperature of alkylation reaction is generally lower than the ordinary pressure boiling point (100 ℃) of water, therefore the utility model discloses the water evaporation pressure in the tubular reactor water evaporation heat removal circulation module is the negative pressure, opens the vacuum pump evacuation in the water evaporation heat removal circulation module earlier, and control pressure is 7~30kpa (a), preferably, control pressure is 15~20kpa (a), and the air that leaks to in the circulation module entrains saturated vapor, takes out to the condensation cooling in the vacuum pump entry condensation cooler, and the condensate water is discharged into the water vapor condensate tank through the pipeline; the cooled air enters a vacuum pump and is directly emptied from an air outlet of the vacuum pump.

In a preferred embodiment, the preheater comprises a preheater I for preheating m-cresol and/or p-cresol and a preheater II for preheating isobutene; the tubular reactor comprises a tubular reactor I, a tubular reactor II and a tubular reactor III which are sequentially connected in series; the high-efficiency mixer comprises a high-efficiency mixer I, a high-efficiency mixer II and a high-efficiency mixer III;

the outlet of the preheater II is respectively connected with the inlet I of the high-efficiency mixer I, the inlet I of the high-efficiency mixer II and the inlet I of the high-efficiency mixer III; the export of pre-heater I links to each other with high-efficient mixer I's entry II, high-efficient mixer I's export links to each other with shell and tube reactor I's feed inlet, shell and tube reactor I's discharge gate links to each other with high-efficient mixer II's entry II, high-efficient mixer II's export links to each other with shell and tube reactor II's feed inlet, shell and tube reactor II's discharge gate links to each other with high-efficient mixer III's entry II, high-efficient mixer III's export links to each other with shell and tube reactor III's feed inlet, shell and tube reactor III's discharge gate links to each other with the entry of surge tank.

Reactive distillation has significant advantages such as improved conversion and selectivity of reactants, reduced equipment investment and operating costs, compact equipment and small space occupation, and the function of accelerating the rate of chemical reaction and mass transfer of a catalyst packed layer, etc. due to the interaction of the distillation operation and the chemical reaction, the use of reactive distillation must also meet some basic requirements, for example, the chemical reaction must be carried out in a liquid phase, the reaction temperature of the main reaction under the operating system pressure is close to the bubble point temperature of the target product, the main reaction cannot be a strong endothermic reaction, etc. The utility model provides a main reaction temperature is 50~90 ℃, and raw materials m-cresol ordinary pressure boiling point is about 202 ℃, mono-tert-butyl product ordinary pressure boiling point is about 230~240 ℃, di-tert-butyl product ordinary pressure boiling point is about 265~295 ℃; even if the reactive distillation column is maintained at an absolute pressure of 5kpa, the boiling point of m-cresol and p-cresol reaches 114 ℃, and the boiling point of the tertiary butyl product is higher. Therefore the industrialization device can't be through selecting suitable reaction rectifying column operating pressure for the reaction temperature of main reaction is close with the bubble point temperature of purpose product, and conventional reaction rectifying column also can't use the utility model discloses in.

The reaction rectifying module in the device comprises a tower feeding vaporizer, a reaction rectifying tower reaction temperature control device and a reaction rectifying tower, wherein the reaction rectifying tower is sequentially provided with a rectifying section, a reaction section and a stripping section from top to bottom, and a tower top condenser and a tower kettle reboiler are not required to be arranged.

The internal part of the rectifying section is a filler or a tray, the rectifying section can be one section or multiple sections, and the rectifying section is multiple sections, namely the rectifying section comprises more than two rectifying sections. The tower of the reaction section is filled with solid catalyst, and the alkylation reaction and the alkylation rectification are coupled, so that the conversion rate of reaction raw materials is improved, and the reaction effect is improved. The reaction section may be one or more stages, and the term "reaction section is a multi-stage" means that it includes two or more reaction sections. The internal part of the stripping section is a filler or a tray, the stripping section can be one section or multiple sections, and the stripping section is multiple sections, namely the stripping section comprises more than two stripping sections.

And a pressure reducing valve is arranged on a pipeline between the pressure stabilizing tank and the tower feeding vaporizer, and the pressure after the valve is controlled to be 5-20 kpa (a) by the pressure reducing valve in the process of transferring the material from the pressure stabilizing tank to the tower feeding vaporizer, and preferably, the pressure is controlled to be 8-12 kpa (a).

For the device, materials in a pressure stabilizing tank are firstly fed into a tower feeding vaporizer, the materials are partially vaporized under the condition of 110-150 ℃, gas-phase materials and liquid-phase materials are respectively formed at the upper part and the lower part of the tower feeding vaporizer, the gas-phase materials mainly comprise isobutene, diisobutylene, partial trimerization isobutene and cresol, and the liquid-phase materials mainly comprise mono-tert-butyl cresol, di-tert-butyl cresol, partial trimerization isobutene and cresol; liquid phase materials are transferred into reaction temperature control equipment (a heat exchanger used for controlling the temperature of the liquid phase materials and capable of realizing the temperature control of the liquid phase materials in the prior art) of the reaction rectifying tower from a liquid phase discharge port arranged on a tower feeding vaporizer for temperature regulation, and the liquid phase materials after the temperature regulation enter the reaction rectifying tower from the upper part of the reaction rectifying tower through a pipeline; the gas phase material enters the reaction rectifying tower from the lower part of the reaction rectifying tower through a pipeline from a gas phase discharge port arranged on the tower feeding vaporizer and is in reverse contact reaction with the liquid phase material entering the reaction rectifying tower in the reaction section.

In order to realize the purpose of the utility model, the reaction rate and the selectivity of the reacted materials in the tubular reactor are improved, the structure and the flow of the reaction rectifying tower are modified, and a tower top condenser and a tower kettle reboiler of the reaction rectifying tower are cancelled; the method comprises the following steps of partially vaporizing the feed by utilizing the characteristics of high light component content and low vaporization temperature in the feed of the reactive distillation tower to provide stable gas-phase and liquid-phase material flows for the reactive distillation tower, wherein the gas phase is rich in isobutene, the liquid phase is cresol and alkylated products, the gas phase enters from the lower part of the reactive distillation tower, and the liquid phase enters from the upper part of the reactive distillation tower; the temperature of the gas phase is gradually reduced from bottom to top, the temperature of the liquid phase is gradually increased from top to bottom, the feeding temperature of the upper liquid phase of the reactive distillation tower is adjusted through reactive temperature control equipment of the reactive distillation tower, and then the temperature of the reactive section is controlled, so that the liquid phase temperature of the reactive section is close to the main reaction temperature, and the coupling operation of reaction and rectification is realized.

The device also provides a method for carrying out alkylation continuous reaction by taking isobutene as an alkylating agent and m-cresol and/or p-cresol (cresol) as a raw material, which comprises the following steps:

(1) uniformly mixing preheated m-cresol and/or p-cresol and isobutene in the high-efficiency mixer, enabling the obtained mixture to enter the tubular reactor through a pipeline from a feed inlet of the tubular reactor, carrying out alkylation reaction at the temperature of 50-90 ℃ and under the pressure of 6-14 barg, and transferring the obtained material after the reaction is finished to a pressure stabilizing tank through a pipeline from a discharge outlet of the tubular reactor; in the alkylation reaction process, introducing deoxygenated water into the tubular reactor, controlling the pressure in a water evaporation heat removal circulating module of the tubular reactor to be 7-30 kpa (a), condensing water vapor generated after negative pressure evaporation in a water vapor condensation cooler through a water vapor outlet of the tubular reactor, introducing condensed water obtained after condensation into a water vapor condensed liquid tank, and introducing the condensed water in the water vapor condensed liquid tank into the tubular reactor to continuously absorb heat for negative pressure evaporation heat removal;

(2) opening a pressure reducing valve, controlling the pressure of the pressure reducing valve to be 5-20 kpa (a), introducing the material in the pressure stabilizing tank into the tower feeding vaporizer, partially vaporizing the material at the temperature of 110-150 ℃, respectively forming a gas-phase material and a liquid-phase material at the upper part and the lower part of the tower feeding vaporizer, transferring the liquid-phase material from a liquid-phase discharge port arranged on the tower feeding vaporizer into a reaction temperature control device of a reaction rectifying tower for temperature adjustment, and introducing the liquid-phase material with the adjusted temperature into the reaction rectifying tower from the upper part of the reaction rectifying tower through a pipeline; and the gas-phase material enters the reaction rectifying tower from the lower part of the reaction rectifying tower through a gas-phase discharge hole arranged on the tower feeding vaporizer through a pipeline, and reacts with the liquid-phase material entering the reaction rectifying tower in a reaction section, wherein the reaction temperature is 50-90 ℃, the reaction pressure is 5-20 kpa (a), the gas-phase material which does not participate in the reaction is extracted from the top of the tower, and the target product is extracted from the bottom of the tower.

In a preferable scheme, in the step (1), the temperature of the alkylation reaction is 60-80 ℃.

In the device, a pressure split-range adjusting system is opened to control the pressure of the alkylation reaction, and further the pressure of the alkylation reaction is 8-10 barg.

Further, a vacuum pump is started to pump vacuum, and the pressure in the water evaporation heat removal circulation module of the tubular reactor is 15-20 kpa (a).

In a preferable scheme, in the step (2), after the pressure reducing valve is opened, the pressure is controlled to be 8-12 kpa (a).

Further, when the material is vaporized in the vaporizer, the temperature of the material in the vaporizer is controlled to be 120-140 ℃.

Further, the reaction temperature is 60-80 ℃ and the reaction pressure is 8-12 kpa (a) during the reaction in the reaction section.

In a preferred scheme, the number of the tubular reactors is 3, and the tubular reactors comprise a tubular reactor I, a tubular reactor II and a tubular reactor III which are sequentially connected in series; the tubes or the spaces between the tubes of each tubular reactor are filled with a catalyst for catalyzing the alkylation reaction of m-cresol and/or p-cresol with isobutene. The number of the high-efficiency mixers is 1 or more.

The internal part of the rectifying section is a filler or a tray, the rectifying section can be one section or multiple sections, and the rectifying section is multiple sections, namely the rectifying section comprises more than two rectifying sections. The tower of the reaction section is filled with solid catalyst which can catalyze the reaction raw materials which do not participate in the materials entering the reaction rectifying tower to continue the reaction, thereby improving the conversion rate of the reaction raw materials and improving the reaction effect. The reaction section may be one or more stages, and the term "reaction section is a multi-stage" means that it includes two or more reaction sections. The internal part of the stripping section is a filler or a tray, the stripping section can be one section or multiple sections, and the stripping section is multiple sections, namely the stripping section comprises more than two stripping sections.

The beneficial effects of the utility model are that:

the utility model provides a device that is used for m-cresol and/or paracresol alkylation continuous reaction, remove heat circulation module and reaction rectification module with shell and tube reaction module, shell and tube reactor water evaporation and couple, in the course of alkylation reaction, combine shell and tube reactor unit volume heat transfer area big, characteristics that the heat transfer coefficient is high, and the water evaporation removes heat circulation module temperature control evenly, the fast advantage of dynamic response, can satisfy the requirement that the strong exothermic reaction in time removed heat and avoided local overtemperature, reaction temperature control is effectual, single equipment productivity is big; the reaction rectification module breaks the equilibrium state limitation of reversible reaction, the reaction rate is high, the selectivity is good, the utilization rate of isobutene raw materials is high, and isobutene recovery facilities do not need to be arranged; the device has the advantages of continuous production, high automation degree, simple structure, improvement on the production efficiency of the whole alkylation reaction, low equipment investment, stable product quality, low energy consumption and the like. It is especially suitable for medium-scale and large-scale alkylation reactions.

Adopt the utility model discloses a device carries out the alkylation reaction, can realize continuous production, and degree of automation is high, and whole alkylation reaction's production efficiency is high, and the reaction temperature controllability is good, production process safety, low in production cost.

Drawings

FIG. 1 is a schematic structural diagram of the device of the present invention;

in the figure, 1 is a preheater I; 2 is a preheater II; 3 is a high-efficiency mixer I; 4 is a high-efficiency mixer II; 5 is a high-efficiency mixer III; 6 is a shell and tube reactor I; 7 is a tubular reactor II; 8 is a shell and tube reactor III; 9 is a water vapor condensing cooler; 10 is a water vapor condensate tank; 11 is a vacuum pump inlet condensing cooler; 12 is a vacuum pump; 13 is a surge tank; 14 is a column feed vaporizer; 15 is a reactive distillation column; 16 is reaction temperature control equipment of the reaction rectifying tower; 17 is a pressure reducing valve; and 18 is a pressure range regulating system.

Detailed Description

In order to make the technical field person understand the utility model scheme better, will combine the utility model embodiment in the following, it is right to technical scheme in the embodiment of the utility model clearly, describe completely. It is to be understood that the specific embodiments disclosed are merely illustrative of certain embodiments of the invention, rather than limiting the invention to its full scope, and that the invention may be embodied more completely within the scope of the appended claims. These embodiments are provided so that this disclosure will be thorough and complete. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

The invention will be further described with reference to the accompanying drawings:

as shown in figure 1, the device comprises a shell and tube reaction module, a shell and tube reactor water evaporation heat removal circulation module and a reaction rectification module:

the tubular reaction module comprises a preheater, a high-efficiency mixer, a tubular reactor and a surge tank 13, wherein the isobutene is fed by adopting a liquid phase, the high-efficiency liquid-liquid mixer can be selected, and different types of high-efficiency mixers are selected according to different phase states of isobutene raw materials; the preheater is connected with the high-efficiency mixer, the high-efficiency mixer is connected with the feed inlet of the tubular reactor, the discharge outlet of the tubular reactor is connected with the surge tank 13, and the surge tank 13 is provided with a pressure range-dividing regulating system 18 for controlling the alkylation reaction pressure in the tubular reactor.

The number of the tubular reactors can be selected according to actual needs, and the number of the tubular reactors is 1 or more according to the limitation requirements of raw materials and products, wherein the plurality of the tubular reactors is more than 2. When the number of the tubular reactors is plural, that is, 2 or more, the tubular reactors are connected in series and/or in parallel. Preferably, the number of the tubular reactors is 1-3. For the tubular reactors in series, the isobutene serving as the alkylating agent can be added all before the first tubular reactor or can be added separately, that is, the isobutene is added before each tubular reactor, and when the isobutene is added separately, the isobutene amount at each addition point can be the same or different, and generally the isobutene amount is fed in progressively one tubular reactor after another.

The number of the high-efficiency mixers can be selected according to actual needs, for example, the number of the high-efficiency mixers is 1, and the number of the high-efficiency mixers can also be multiple. Generally, when the number of the tubular reactors is plural, each tubular reactor may be provided with a high-efficiency mixer or other similar equipment for dispersing and uniformly mixing. The tubular reactor may be one commonly used in the market, and has no strict limitation on its specification, and has catalyst for the alkylation of m-cresol and/or p-cresol with isobutene filled inside or between the tubes. As for the catalyst, a liquid catalyst can be selected, a solid catalyst can be selected, and the catalyst can be selected according to actual needs. For the solid catalyst, it may be packed in the tubes of the tubular reactor or between the tubes of the tubular reactor.

In the figure 1, m-cresol and/or p-cresol and liquid phase isobutene are preheated in a preheater I1 and a preheater II 2 respectively to 40-70 ℃; the tubular reactor comprises a tubular reactor I6, a tubular reactor II 7 and a tubular reactor III 8 which are connected in series in sequence; the high-efficiency mixer comprises a high-efficiency mixer I3, a high-efficiency mixer II 4 and a high-efficiency mixer III 5.

The outlet of the preheater II 2 is respectively connected with the inlet I of the high-efficiency mixer I3, the inlet I of the high-efficiency mixer II 4 and the inlet I of the high-efficiency mixer III 5; the export of preheater I1 links to each other with high-efficient mixer I3's entry II, high-efficient mixer I3's export links to each other with shell and tube reactor I6's feed inlet, shell and tube reactor I6's discharge gate links to each other with high-efficient mixer II 4's entry II, high-efficient mixer II 4's export links to each other with shell and tube reactor II 7's feed inlet, shell and tube reactor II 7's discharge gate links to each other with high-efficient mixer III 5's entry II, high-efficient mixer III 5's export links to each other with shell and tube reactor III 8's feed inlet, shell and tube reactor III 8's discharge gate links to each other with surge tank 13's entry.

When 3 tubular reactors connected in series are arranged in the device, the liquid phase isobutene can be added in front of the tubular reactor I6; the adding amount can be divided into 3 times, 40-100% of the total amount is added before the tubular reactor I6, 0-50% of the total amount is added before the tubular reactor II 7, and 0-30% of the total amount is added before the tubular reactor III 8. For example, liquid phase isobutylene is fed as follows: 65% of the total amount was added before the tubular reactor I6, 25% of the total amount was added before the tubular reactor II 7 and 10% of the total amount was added before the tubular reactor III 8.

Dispersing and mixing liquid phase isobutene added at the first position and m-cresol and/or p-cresol in a high-efficiency mixer I3, and then sending the mixture to a tubular reactor I6 for alkylation reaction, wherein the reaction temperature is 50-90 ℃, and preferably 60-80 ℃; the reaction pressure is 6 to 14barg, preferably 8 to 10 barg.

The liquid phase isobutene added at the second position and the alkylation reaction product are dispersed and mixed in a high-efficiency mixer II 4, and then are sent to a tubular reactor II 7 for alkylation reaction, wherein the reaction temperature is 50-90 ℃, and preferably 60-80 ℃; the reaction pressure is 6 to 14barg, preferably 8 to 10 barg.

Dispersing and mixing the liquid phase isobutene added at the third position and an alkylation reaction product in a high-efficiency mixer III 5, and then sending the mixture to a tubular reactor III 8 for alkylation reaction, wherein the reaction temperature is 50-90 ℃, and preferably 60-80 ℃; the reaction pressure is 6 to 14barg, preferably 8 to 10 barg.

The shell and tube reactor water evaporation heat removal circulation module comprises a water vapor condensation cooler 9, a water vapor condensate tank 10, a vacuum pump inlet condensation cooler 11 and a vacuum pump 12, wherein the water vapor condensation cooler 9 can be an air cooler, and compared with the use of circulating water condensation cooling, the production energy consumption of the device can be reduced; the condensing cooler 11 at the inlet of the vacuum pump is cooled by circulating water due to lower cooling temperature; the steam outlet of tubular reactor I6, the steam outlet of tubular reactor II 7 and the steam outlet of tubular reactor III 8 link to each other with the entry of steam condensate cooler 9 through the pipeline respectively, the export of steam condensate cooler 9 links to each other with the entry I of steam condensate tank 10, the export I of steam condensate tank 10 links to each other with the water inlet of tubular reactor I6 respectively, the water inlet of tubular reactor II 7 and the water inlet of tubular reactor III 8 link to each other, the export II of steam condensate tank 10 links to each other with the entry of vacuum pump entry condensate cooler 9, the export I of vacuum pump entry condensate cooler 9 links to each other with the import II of steam condensate tank 10, the export II of vacuum pump entry condensate cooler 9 links to each other with vacuum pump 12.

During the alkylation reaction, the pressure in the tubular reactor water evaporation heat removal circulation module is controlled by vacuum pumping of a vacuum pump, and the pressure in the tubular reactor water evaporation heat removal circulation module is controlled to be 7-30 kpa (a), preferably 15-20 kpa (a).

Be equipped with pressure journey governing system 18 on surge tank 13, steerable shell and tube reactor pressure during alkylation reaction, the utility model discloses well control shell and tube reactor's pressure is 6~14barg, and preferred 8~10 barg.

The reaction rectification module comprises a tower feeding vaporizer 14, a reaction rectification tower reaction temperature control device 16 and a reaction rectification tower 15, wherein the tower feeding vaporizer 14 and the reaction rectification tower reaction temperature control device 16 can respectively select a tubular heat exchanger, a pressure stabilizing tank 13 is connected with an inlet of the tower feeding vaporizer 14, a pressure reducing valve 17 is arranged on a pipeline between the pressure stabilizing tank 13 and the tower feeding vaporizer 14, a gas phase discharge port of the tower feeding vaporizer 14 is connected with the lower part of the reaction rectification tower 15, a liquid phase discharge port of the tower feeding vaporizer 14 is connected with an inlet of the reaction rectification tower reaction temperature control device 16, an outlet of the reaction rectification tower reaction temperature control device 16 is connected with the upper part of the reaction rectification tower 15, and the reaction rectification tower 15 is sequentially provided with a rectification section, a reaction section and a stripping section from top to bottom.

A pressure reducing valve 17 is arranged on a pipeline between the pressure stabilizing tank 13 and the tower feeding vaporizer 14, and after the pressure reducing valve 17 is opened, the pressure behind the control valve is 5-20 kpa (a), preferably 8-12 kpa (a).

Further, after the pressure reducing valve 17 is opened, the material in the surge tank 13 is introduced into the tower feed vaporizer 14, the material is partially vaporized under the temperature of 110-150 ℃, a gas phase material and a liquid phase material are respectively formed at the upper part and the lower part of the tower feed vaporizer 14, and preferably, when the material is vaporized in the tower feed vaporizer 14, the temperature of the material in the vaporizer 14 is controlled to be 120-140 ℃.

Liquid phase materials are transferred into a reaction temperature control device 16 of the reaction rectifying tower from a liquid phase discharge port arranged on a tower feeding vaporizer 14 for temperature adjustment, and the liquid phase materials after temperature adjustment enter the reaction rectifying tower 15 from the upper part of the reaction rectifying tower 15 through a pipeline; gas-phase materials enter the reaction rectifying tower 15 from a gas-phase discharge port arranged on the tower feeding vaporizer 14 through a pipeline from the lower part of the reaction rectifying tower 15, and react with the liquid-phase materials entering the reaction rectifying tower in a reaction section, wherein the reaction temperature is 50-90 ℃, the reaction pressure is 5-20 kpa (a), the gas-phase materials which do not participate in the reaction are extracted from the top of the tower, and target products are extracted from the bottom of the tower.

In a preferred embodiment, the reaction temperature is 60-80 ℃ and the reaction pressure is 8-12 kpa (a) during the reaction in the reaction section.

The utility model discloses a use as follows:

example 1

This example is the alkylation of p-cresol with isobutylene in liquid phase to produce di-t-butyl-p-cresol (BHT). The tubular reactors are characterized in that 3 tubular reactors are selected to be connected in series, namely a tubular reactor I, a tubular reactor II and a tubular reactor III, and a solid catalyst is filled in a tube of each tubular reactor. Each tubular reactor is provided with 3 high-efficiency liquid-liquid mixers, namely a high-efficiency liquid-liquid mixer I, a high-efficiency liquid-liquid mixer II and a high-efficiency liquid-liquid mixer III. The liquid phase isobutene, added in 3 portions, was fed according to the following scheme, with 65% of the total amount being added before the tubular reactor I6, 25% of the total amount being added before the tubular reactor II 7 and 10% of the total amount being added before the tubular reactor III 8.

The pressure of the pressure stabilizing tank is controlled to be 8barg by a split-range adjusting system on the pressure stabilizing tank, so that flash evaporation vaporization is not generated after the liquid phase isobutene enters the tube type reaction module, and alkylation reaction is carried out in a liquid phase.

And (3) opening a vacuum pump, controlling the pressure of a condensing cooler at the inlet of the vacuum pump to be 10kPa (a), and controlling the pressure at the steam outlet of the tubular reactor to be about 16kPa (a) and the corresponding water saturation temperature to be about 55 ℃ in the production process.

10kmol/h of p-cresol was added to preheater I and preheated to 60 deg.C, 15.6kmol/h of liquid phase isobutene was added to preheater II and preheated to 60 deg.C. And fully mixing the preheated two materials in a high-efficiency liquid-liquid mixer I, and then sending the mixture to a tubular reactor I for alkylation reaction. Controlling the reaction temperature of the tubular reactor I to be 65 ℃ and the reaction pressure to be 9.5 barg; the reaction residence time in the tubular reactor I is 0.5-1.5 h.

Conveying an alkylation reaction product to a discharge port of the tubular reactor I to enter a high-efficiency liquid-liquid mixer II, simultaneously adding 6kmol/h of liquid-phase isobutene to the high-efficiency liquid-liquid mixer II, fully mixing two materials in the high-efficiency liquid-liquid mixer II, and then conveying the two materials to the tubular reactor II for further reaction; controlling the reaction temperature in the tubular reactor II to be 70 ℃ and the reaction pressure to be 9 barg; the reaction time in the tubular reactor II is 1-2 h.

A discharge port of the tubular reactor II conveys an alkylation reaction product into a high-efficiency liquid-liquid mixer III, simultaneously 2.4kmol/h of liquid phase isobutene is added into the high-efficiency liquid-liquid mixer III, and the two materials are fully mixed in the high-efficiency liquid-liquid mixer III and then conveyed to the tubular reactor III for further reaction; controlling the reaction temperature in the tubular reactor III to be 75 ℃ and the reaction pressure to be 8.5 barg; the reaction residence time in the tubular reactor III is 1-2 h.

The discharge port of the tubular reactor III delivers the alkylation reaction product to a surge tank, which is used to adjust and control the reaction pressure of the tubular reactor, in this example, the operating temperature of the surge tank is 75 ℃, and the operating pressure is 8 barg.

The alkylation reaction product in the pressure stabilizing tank is decompressed by a pressure reducing valve and then is sent to a tower feeding vaporizer. Controlling the pressure of the pressure reducing valve to be 10kpa (a), flashing is carried out after the pressure reducing valve, the temperature of material flow after the valve is reduced by about 5 ℃, meanwhile, the phase state of the material flow is changed from a liquid phase to a gas-liquid two phase, and the mass fraction of the gas phase is about 4%;

further, the gas-liquid two-phase material flow after the pressure reducing valve is sent to a tower feeding vaporizer and heated to 130 ℃ to form gas-phase materials and liquid-phase materials, wherein the mass fraction of the gas phase is about 15%; the molar composition of the gas phase feed was as follows: 33% of isobutene, 29% of diisobutylene, 16% of trimerized isobutene, 4% of p-cresol, 13% of mono-tert-butyl-p-cresol and 5% of di-tert-butyl-p-cresol; the liquid phase material had the following rough molar composition: 2% of diisobutylene, 5% of trimerized isobutylene, 4% of p-cresol, 41% of mono-tert-butyl-p-cresol and 48% of di-tert-butyl-p-cresol.

The liquid phase material in the tower feeding vaporizer is adjusted to 60 ℃ by a reaction temperature device (such as a tubular heat exchanger) of the reaction rectifying tower, enters from the upper part of the reaction rectifying tower, and the gas phase material enters from the lower part of the reaction rectifying tower. The reactive distillation tower is provided with 1 section of distillation section, 2 sections of reaction sections (each reaction section is filled with a solid catalyst) and 1 section of stripping section; and carrying out alkylation reaction on isobutene, p-cresol and mono-tert-butyl-p-cresol in a reaction section at the reaction pressure of 10kpa (a), wherein the temperature ranges of the upper end and the lower end of the reaction section are 62-72 ℃.

Micro isobutene (less than 0.5 percent), discharging isobutene dimer from the top of the reaction rectifying tower, and discharging isobutene trimer, mono-tertiary butyl-p-cresol and di-tertiary butyl-p-cresol from the bottom of the reaction rectifying tower; the isobutene content at the top of the tower is very low, and a recovery device is not needed; and (4) feeding the tower bottom material to a rectifying tower for refining to obtain the high-purity di-tert-butyl-p-cresol.

Other processes of the utility model can adopt the prior art.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing detailed description, or equivalent replacements may be made for some of the technical features of the embodiments. All utilize the equivalent structure that the specification content was done, direct or indirect application is in other relevant technical field, all the same reason is in the utility model discloses within the patent protection scope.

Claims

1. A device for the alkylation continuous reaction of m-cresol and/or p-cresol is characterized by comprising a tubular reaction module, a tubular reactor water evaporation heat removal circulation module and a reaction rectification module:

the tubular reaction module comprises a preheater, a high-efficiency mixer, a tubular reactor and a pressure stabilizing tank, wherein the preheater is connected with the high-efficiency mixer, the high-efficiency mixer is connected with a feed inlet of the tubular reactor, a discharge outlet of the tubular reactor is connected with the pressure stabilizing tank, and the pressure stabilizing tank is provided with a pressure split-range adjusting system;

the reactive distillation module comprises a tower feeding vaporizer, reactive distillation tower reaction temperature control equipment and a reactive distillation tower, wherein a surge tank is connected with an inlet of the tower feeding vaporizer, a pressure reducing valve is arranged on a pipeline between the surge tank and the tower feeding vaporizer, a gas-phase discharge port of the tower feeding vaporizer is connected with the lower part of the reactive distillation tower, a liquid-phase discharge port of the tower feeding vaporizer is connected with an inlet of the reactive distillation tower reaction temperature control equipment, an outlet of the reactive distillation tower reaction temperature control equipment is connected with the upper part of the reactive distillation tower, and the reactive distillation tower is sequentially provided with a distillation section, a reaction section and a stripping section from top to bottom.

2. The apparatus according to claim 1, wherein the number of the shell and tube reactors is 1 or more.

3. The device according to claim 2, wherein the number of the shell and tube reactors is multiple, and the shell and tube reactors are connected in series and/or in parallel.

4. The device according to claim 3, wherein the number of the tubular reactors is 3, and the 3 tubular reactors are connected in series.

5. The apparatus according to claim 1, wherein the tubes or spaces between the tubes of the shell-and-tube reactor are packed with a catalyst for catalyzing the alkylation of m-cresol and/or p-cresol with isobutylene.

6. The apparatus of claim 1, wherein the number of the high-efficiency mixers is 1 or more.

7. The apparatus of claim 6, wherein the number of high efficiency mixers is 3.

8. The apparatus according to claim 4, wherein the preheater comprises a preheater I for preheating m-cresol and/or p-cresol and a preheater II for preheating isobutene; the shell and tube reactor comprises a shell and tube reactor I, a shell and tube reactor II and a shell and tube reactor III which are connected in series in sequence; the high-efficiency mixer comprises a high-efficiency mixer I, a high-efficiency mixer II and a high-efficiency mixer III;

the outlet of the preheater II is respectively connected with the inlet I of the high-efficiency mixer I, the inlet I of the high-efficiency mixer II and the inlet I of the high-efficiency mixer III; the export of pre-heater I with high-efficient blender I's entry II links to each other, high-efficient blender I's export with tubular reactor I's feed inlet links to each other, tubular reactor I's discharge gate with high-efficient blender II's entry II links to each other, high-efficient blender II's export with tubular reactor II's feed inlet links to each other, tubular reactor II's discharge gate with high-efficient blender III's entry II links to each other, high-efficient blender III's export with tubular reactor III's feed inlet links to each other, tubular reactor III's discharge gate with the entry of surge tank links to each other.

9. The apparatus of claim 1, wherein the column internals of the rectification section are packing or trays, and the rectification section is one or more sections; the internal part of the stripping section is a filler or a tray, and the stripping section is one section or a plurality of sections.

10. The apparatus of claim 1, wherein the reaction section comprises one or more stages, and the column is packed with the solid catalyst.