阅读说明：本技术 一种溴化丁基橡胶的生产工艺 (Production process of brominated butyl rubber ) 是由 许晓双 王德恩 葛良国 滕杰 王海矫 栾波 任学斌 王衍金 于 2020-07-27 设计创作，主要内容包括：本发明提供了一种溴化丁基橡胶的生产工艺。本发明对溴化丁基橡胶生产工艺中的溶剂回收系统进行改进,在闪蒸罐前设置汽水混合器和胶水静态混合器,将热水与蒸汽通入汽水混合器中,再将汽水混合物和胶液一并通入胶水静态混合器中,对胶液升温,然后再进入闪蒸罐进行闪蒸及后续流程,提高了进入闪蒸罐中的物料温度,提前将部分气化热量给到胶粒与溶剂,并在输送管道中形成胶液液滴与水的分散相,进入闪蒸罐后,迅速气化、闪蒸,在胶粒表面形成孔道,并在闪蒸罐内的搅拌作用下进一步减小胶粒尺寸,提高了闪蒸脱溶剂效果,还减少了胶液挂壁现象,从而提高了溶剂回收效率、降低了整体溶剂单耗,并减少了堵泵及停工的风险,保证了溴化丁基橡胶生产运行周期。(The invention provides a production process of brominated butyl rubber. The invention improves a solvent recovery system in a production process of brominated butyl rubber, a steam-water mixer and a glue static mixer are arranged in front of a flash tank, hot water and steam are introduced into the steam-water mixer, then the steam-water mixture and glue solution are introduced into the glue static mixer together, the glue solution is heated, then the glue solution enters the flash tank for flash evaporation and subsequent processes, the temperature of materials entering the flash tank is improved, part of gasification heat is given to colloidal particles and solvent in advance, a disperse phase of glue solution droplets and water is formed in a conveying pipeline, after the glue solution droplets and the water disperse phase enter the flash tank, the glue solution is quickly gasified and flash evaporated, pore channels are formed on the surface of the colloidal particles, the size of the colloidal particles is further reduced under the stirring action in the flash tank, the flash evaporation and solvent removal effects are improved, the phenomenon of wall hanging of the glue solution is also reduced, the solvent recovery efficiency is improved, the unit consumption of the whole solvent, the production and operation period of the brominated butyl rubber is ensured.)

1. A production process of brominated butyl rubber is characterized by comprising the following steps:

a) allowing the butyl rubber sol to enter a bromination system for bromination reaction to obtain a brominated rubber solution;

b) the brominated glue solution enters a neutralization system for neutralization reaction to obtain a neutralized glue solution;

c) the neutralized glue solution enters a solvent recovery system to remove the solvent, so that brominated butyl rubber and the recovered solvent are obtained respectively;

the solvent recovery system includes:

a vapor-water mixer;

the glue static mixer is communicated with the feed inlet and the discharge outlet of the steam-water mixer; the feed inlet of the glue static mixer is also communicated with a neutralizing glue liquid outlet of the neutralizing system;

the feed inlet is communicated with the discharge outlet of the glue static mixer;

the feed inlet of the vacuum stripping tower is communicated with the discharge outlet of the flash tank;

the gas inlet is respectively communicated with the top exhaust port of the vacuum stripping tower and the top exhaust port of the flash tank;

the operation process of the solvent recovery system comprises the following steps:

hot water and steam are respectively introduced into the steam-water mixer, the obtained steam-water mixture is fed into a glue static mixer, meanwhile, a neutralized glue solution generated by a neutralization system is fed into the glue static mixer, the steam-water mixture and the neutralized glue solution are mixed in the glue static mixer to heat the glue solution, the obtained heated glue solution is sequentially fed into a flash tank for flash evaporation and a vacuum stripping tower for steam stripping, solvents removed in the flash evaporation and steam stripping processes are respectively discharged through a top exhaust port of the flash tank and a top exhaust port of the stripping tower and enter a solvent recovery tank for recovering the obtained solvents, and the brominated butyl rubber is obtained at the bottom of the vacuum stripping tower;

and the temperature of the heated glue solution obtained after heating is 68-85 ℃.

2. The production process according to claim 1, wherein the delivery flow rate of the hot water introduced into the steam-water mixer is 60-100 t/h;

the delivery flow of the steam into the steam-water mixer is 1.5-3.2 t/h.

3. The production process according to claim 1 or 2, wherein the steam is 0.35MPa steam.

4. The process according to claim 1, wherein the flash tank is characterized in that the nozzle is at an angle of < 90 ° to the side wall of the flash tank.

5. The process according to claim 1 or 4, wherein in the flash tank, the angle between the nozzle and the side wall of the flash tank is 60 °.

6. The production process according to claim 1 or 2, wherein in the flash tank, the baffle is a triangular prism baffle.

7. The production process of claim 1, wherein in the bromination system, the upper part or the top of the bromination reaction kettle is communicated with a nitrogen pressurization system;

and pressurizing the bromination reaction kettle through the nitrogen pressurization system, so that the pressure of the glue solution entering the bromination reaction kettle is increased by 10-20 kPa.

8. The production process according to claim 1 or 2, characterized in that the vacuum stripper is a two-stage vacuum stripper, in particular comprising two one-stage vacuum strippers and a two-stage vacuum stripper connected in series with each other.

9. The production process according to claim 1, wherein the operating temperature of the flash tank is 80-120 ℃;

the operating temperature of the vacuum stripping tower is 68-100 ℃.

10. The production process according to claim 8, wherein the operation temperature of the primary vacuum stripping tower is 75-100 ℃;

the operation temperature of the secondary vacuum stripping tower is 68-80 ℃.

Technical Field

The invention relates to the field of rubber, in particular to a production process of brominated butyl rubber.

Background

The butyl rubber (IIR) is formed by polymerizing isobutene and a small amount of isoprene, has chemical stability and thermal stability, and is outstanding in air tightness and water tightness. Brominated butyl rubber (BIIR) is a product obtained by modifying butyl rubber (IIR) through bromination. Bromine atoms are introduced into IIR molecules, but the main chain structure of IIR is not changed, so BIIR has all the characteristics of IIR. For BIIR, due to the introduction of bromine atoms, not only the double bond is activated; a new crosslinking position is generated, so that the vulcanization speed is greatly increased, and the vulcanization mode can be diversified; the viscosity of the rubber is increased, and the compatibility with other rubbers is enhanced; in order to improve the mechanical property and the processing property of the rubber, white carbon black is generally added for reinforcement. BIIR has good chemical stability, thermal stability, aging resistance, ozone resistance, electrical insulation, shock absorption, and low water absorption.

BIIR is one of the representatives of high-performance and high-value-added synthetic rubbers, is a new strategic material, and is widely used in tubeless tires of automobiles, medical products and rubber industrial products. With the increasing production demand of BIIR, improvement of its production technology and improvement of production efficiency are urgently desired. The improvement of the production efficiency is mainly realized by the improvement of the production operation period, the whole production process is controlled, and the abnormal frequency is reduced.

The BIIR production process is shown in FIG. 1, and FIG. 1 is a process flow diagram of a production process of brominated butyl rubber (BIIR) in the prior art. The front path provides colloidal particle water with stable concentration, the bromination working section is an important link of the whole BIIR production process and mainly comprises a colloidal particle tank working section, a dehydration working section, a halogenation feeding preparation working section, a halogenation reaction and neutralization working section, a solvent recovery working section, a water recovery and circulation working section, an additive preparation working section and a discharge gas washing tower working section.

Firstly, a glue solution tank system provides proper buffering and staying to stabilize the feeding of a halogenation unit, so that the feeding continuity of a reactor is ensured according to the average value of the inflow of slurry, and the production continuity is finally ensured;

the dehydration section converts about 5 percent of colloidal particle water into about 50 percent of colloidal particle water through a vibrating screen which is switched regularly, and the colloidal particle water is dehydrated to a wet and solid state by a screw extruder to wait for next colloidal particle;

thirdly, the halogenated feed preparation section is mainly used for carrying out sol by cold and hot hexane, and finally, a sol solution with the concentration of 10-30 wt% is prepared for carrying out the next bromination reaction;

and fourthly, the halogenation reaction and neutralization section comprises a bromination reaction and neutralization process, the glue solution obtained in the previous process is cooled and injected into a bromination reactor, bromine diluted by hexane is injected through an upper inner insert tube and a lower inner insert tube, and the glue solution subjected to the bromination reaction contains unreacted bromine and generated hydrogen bromide and needs to be effectively neutralized through alkali liquor with certain concentration.

And fifthly, the solvent recovery section mainly comprises a hexane removal process, hexane is evaporated and removed for recovery, the glue solution becomes colloidal particle water again and is conveyed to a post-treatment drying section for drying and the like.

In the working section, the removal degree of hexane in the glue solution determines the length of the production running period and the unit consumption of hexane. Actual engineering experience shows that when the hexane removal effect is poor in the process, the content of residual hexane in the glue solution is high, the glue is sticky, the wall is easy to hang, a pump is easy to block, the reduction or forced shutdown is caused, and the overall production efficiency is seriously influenced.

Disclosure of Invention

In view of the above, the present invention provides a production process of brominated butyl rubber. The production process provided by the invention can effectively remove the hexane solvent, reduce the hexane content in the rubber, reduce the total consumption cost of hexane, ensure that the rubber liquid is easy to convey, reduce wall hanging and blockage, and reduce the risks of pump blockage and shutdown, thereby ensuring the production operation period of the brominated butyl rubber and improving the overall production efficiency.

The invention provides a production process of brominated butyl rubber, which comprises the following steps:

a) allowing the butyl rubber sol to enter a bromination system for bromination reaction to obtain a brominated rubber solution;

b) the brominated glue solution enters a neutralization system for neutralization reaction to obtain a neutralized glue solution;

c) the neutralized glue solution enters a solvent recovery system to remove the solvent, so that brominated butyl rubber and the recovered solvent are obtained respectively;

the solvent recovery system includes:

a vapor-water mixer;

the glue static mixer is communicated with the feed inlet and the discharge outlet of the steam-water mixer; the feed inlet of the glue static mixer is also communicated with a neutralizing glue liquid outlet of the neutralizing system;

the feed inlet is communicated with the discharge outlet of the glue static mixer;

the feed inlet of the vacuum stripping tower is communicated with the discharge outlet of the flash tank;

the gas inlet is respectively communicated with the top exhaust port of the vacuum stripping tower and the top exhaust port of the flash tank;

the operation process of the solvent recovery system comprises the following steps:

hot water and steam are respectively introduced into the steam-water mixer, the obtained steam-water mixture is fed into a glue static mixer, meanwhile, a neutralized glue solution generated by a neutralization system is fed into the glue static mixer, the steam-water mixture and the neutralized glue solution are mixed in the glue static mixer to heat the glue solution, the obtained heated glue solution is sequentially fed into a flash tank for flash evaporation and a vacuum stripping tower for steam stripping, solvents removed in the flash evaporation and steam stripping processes are respectively discharged through a top exhaust port of the flash tank and a top exhaust port of the stripping tower and enter a solvent recovery tank for recovering the obtained solvents, and the brominated butyl rubber is obtained at the bottom of the vacuum stripping tower;

and the temperature of the heated glue solution obtained after heating is 68-85 ℃.

Preferably, the delivery flow of the hot water introduced into the steam-water mixer is 60-100 t/h;

the delivery flow of the steam into the steam-water mixer is 1.5-3.2 t/h.

Preferably, the steam is 0.35MPa steam.

Preferably, in the flash tank, the included angle between the nozzle and the side wall of the flash tank is less than 90 degrees.

Preferably, in the flash tank, the included angle between the nozzle and the side wall of the flash tank is 60 degrees.

Preferably, in the flash tank, the baffle is a triangular prism baffle.

Preferably, in the bromination system, the upper part or the top of the bromination reaction kettle is communicated with a nitrogen pressurization system;

and pressurizing the bromination reaction kettle through the nitrogen pressurization system, so that the pressure of the glue solution entering the bromination reaction kettle is increased by 10-20 kPa.

Preferably, the vacuum stripping tower is a two-stage vacuum stripping tower, and specifically comprises a first-stage vacuum stripping tower and a second-stage vacuum stripping tower which are connected in series.

Preferably, the operating temperature of the flash tank is 80-120 ℃;

the operating temperature of the vacuum stripping tower is 68-100 ℃.

Preferably, the operating temperature of the primary vacuum stripping tower is 75-100 ℃;

the operation temperature of the secondary vacuum stripping tower is 68-80 ℃.

The invention improves a solvent recovery system in a production process of brominated butyl rubber, a steam-water mixer and a glue static mixer (equivalent to a glue solution heating system) are arranged in front of a flash tank, hot water and steam are introduced into the steam-water mixer, then the steam-water mixture and the glue solution are introduced into the glue static mixer together, the glue solution is heated, the glue solution is controlled to be heated to 68-85 ℃ from the original 50-60 ℃, then the glue solution enters the flash tank for flash evaporation and subsequent processes, the temperature of materials entering the flash tank is improved, part of gasification heat is given to colloidal particles and solvent in advance, a dispersed phase of liquid drops and water is formed in a conveying pipeline, the colloidal particles are quickly gasified and flash evaporated after entering the flash tank, pore channels are formed on the surface of the colloidal particles, the size of the colloidal particles is further reduced under the stirring effect in the flash tank, the flash evaporation and the effect of solvent removal is improved, and the phenomenon, therefore, the solvent recovery efficiency is improved, the unit consumption of the whole solvent is reduced, and wall hanging and blockage are reduced, so that the risks of pump blockage and shutdown are reduced, the production operation period of the brominated butyl rubber is ensured, and the whole production efficiency is improved.

Experimental results show that the production process provided by the invention reduces the unit consumption of hexane to below 36.3kg/t glue, and reduces the NMHC content of tail gas to 689mg/m³And the pump plugging period is prolonged to more than 5 days, so that the hexane recovery efficiency is greatly improved, the hexane unit consumption in the production of brominated butyl rubber is reduced, the integral operation period of the device is prolonged, and the production efficiency is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a flow diagram of a prior art process for the production of brominated butyl rubber (BIIR);

FIG. 2 is a schematic diagram of the bromination system-neutralization system of the present invention;

FIG. 3 is a schematic view of the solvent recovery system of the present invention;

FIG. 4 is a schematic diagram of a prior art flash tank configuration;

FIG. 5 is a schematic diagram of the structure of a flash tank employed in some embodiments of the present invention;

fig. 6 is a schematic diagram of the baffles in the flash tank.

Detailed Description

The invention provides a production process of brominated butyl rubber, which comprises the following steps:

a) allowing the butyl rubber sol to enter a bromination system for bromination reaction to obtain a brominated rubber solution;

b) the brominated glue solution enters a neutralization system for neutralization reaction to obtain a neutralized glue solution;

c) the neutralized glue solution enters a solvent recovery system to remove the solvent, so that brominated butyl rubber and the recovered solvent are obtained respectively;

the solvent recovery system includes:

a vapor-water mixer;

the glue static mixer is communicated with the feed inlet and the discharge outlet of the steam-water mixer; the feed inlet of the glue static mixer is also communicated with a neutralizing glue liquid outlet of the neutralizing system;

the feed inlet is communicated with the discharge outlet of the glue static mixer;

the feed inlet of the vacuum stripping tower is communicated with the discharge outlet of the flash tank;

the gas inlet is respectively communicated with the top exhaust port of the vacuum stripping tower and the top exhaust port of the flash tank;

the operation process of the solvent recovery system comprises the following steps:

hot water and steam are respectively introduced into the steam-water mixer, the obtained steam-water mixture is fed into a glue static mixer, meanwhile, a neutralized glue solution generated by a neutralization system is fed into the glue static mixer, the steam-water mixture and the neutralized glue solution are mixed in the glue static mixer to heat the glue solution, the obtained heated glue solution is sequentially fed into a flash tank for flash evaporation and a vacuum stripping tower for steam stripping, solvents removed in the flash evaporation and steam stripping processes are respectively discharged through a top exhaust port of the flash tank and a top exhaust port of the stripping tower and enter a solvent recovery tank for recovering the obtained solvents, and the brominated butyl rubber is obtained at the bottom of the vacuum stripping tower;

and the temperature of the heated glue solution obtained after heating is 68-85 ℃.

The invention improves a solvent recovery system in a production process of brominated butyl rubber, a steam-water mixer and a glue static mixer (equivalent to a glue solution heating system) are arranged in front of a flash tank, hot water and steam are introduced into the steam-water mixer, then the steam-water mixture and the glue solution are introduced into the glue static mixer together, the glue solution is heated, the glue solution is controlled to be heated to 68-85 ℃ from the original 50-60 ℃, then the glue solution enters the flash tank for flash evaporation and subsequent processes, the temperature of the material entering the flash tank is increased, part of gasification heat is given to colloidal particles and the solvent in advance, a dispersed phase of liquid drops and water is formed in a conveying pipeline, the colloidal particles are quickly gasified and flash evaporated after entering the flash tank, pore channels are formed on the surface of the colloidal particles, the size of the colloidal particles is further reduced under the stirring effect in the flash tank, the flash evaporation desolventizing effect is improved, and, therefore, the solvent recovery efficiency is improved, the unit consumption of the whole solvent is reduced, and wall hanging and blockage are reduced, so that the risks of pump blockage and shutdown are reduced, the production operation period of the brominated butyl rubber is ensured, and the whole production efficiency is improved.

According to the invention, butyl rubber sol enters a bromination system to undergo bromination reaction, so as to obtain a brominated rubber solution. And (4) allowing the obtained brominated glue solution to enter a neutralization system for neutralization reaction to obtain a neutralized glue solution.

In the invention, the butyl rubber sol is obtained by processing according to a preorder flow in a brominated butyl rubber process flow well known to a person skilled in the art, referring to fig. 1, the butyl rubber sol is obtained after a series of preorder preparation, and then the butyl rubber sol is sent to a bromination unit to start the subsequent preparation of the brominated butyl rubber.

In the invention, preferably, a nitrogen pressurization system is added in front of the bromination system, the bromination reaction kettle is pressurized by the nitrogen pressurization system, the mechanical seal pressure of the reaction kettle is improved, the pressure of the glue solution entering the bromination reaction kettle is improved, the pressure drop generated by a subsequent glue solution heating system is met, the glue solution is ensured to smoothly enter a flash tank through a nozzle after undergoing the pressure drop, and the production efficiency is favorably improved. In the invention, the pressure of the glue solution entering the bromination reaction kettle is preferably increased by 10-20 KPa through a nitrogen pressurization system; in some embodiments of the invention, the pressure is increased by 15 KPa.

In the present invention, the bromination system-neutralization system specifically includes:

a nitrogen pressurization system;

the bromination reaction kettle is communicated with the nitrogen pressurization system;

the feeding port of the staying kettle is communicated with the discharging port of the bromination reaction kettle;

and the feeding port is communicated with the discharging port of the staying kettle.

Referring to fig. 2, fig. 2 is a schematic diagram of a bromination system-neutralization system in accordance with the present invention. Wherein, 1 is a nitrogen pressurization system, 2 is a bromination reaction kettle, 3 is a retention kettle, 4 is a neutralization kettle, and 5 is a mixer.

The nitrogen pressurization system 1 utilizes nitrogen pressurization to increase the pressure of the reaction kettle. In some embodiments of the present invention, the nitrogen booster system 1 is a nitrogen booster pump. The gas outlet of the nitrogen pressurization system 1 is connected with the subsequent bromination reaction kettle 2 in a mechanical seal way, and finally injected nitrogen enters the bromination reaction kettle 2 for pressurization; in the present invention, the pressure is preferably increased by 10 to 20 KPa.

The bromination reaction kettle 2 is used for receiving the butyl rubber glue solution generated in the preorder procedure and receiving bromine, so that the glue solution and the bromine are subjected to bromination reaction to generate brominated butyl rubber. The upper part or the top of the bromination reaction kettle 2 is provided with a butyl rubber glue solution inlet which is communicated with a butyl rubber glue solution outlet of the previous procedure and receives the butyl rubber glue solution from the previous procedure. The upper part or the top of the bromination reaction kettle 2 is also provided with a bromine inlet for receiving bromine. In some embodiments of the present invention, the system further comprises a mixer 5, a discharge port of the mixer 5 is communicated with a bromine feed port of the bromination reaction kettle 2, bromine and the solvent are fed into the mixer 5 in advance to be mixed, and the obtained bromine solution is fed into the bromination reaction kettle 2. In some embodiments of the invention, the mixer 5 is a static mixer. Still be provided with the agitator in bromination reation kettle 2, connect in bromination reation kettle 2's top and vertically stretch into bromination reation kettle 2 for the raw materials of receiving in the stirred tank. The bottom of the bromination reaction kettle 2 is provided with a discharge hole for discharging the brominated butyl rubber liquid formed by the reaction in the kettle and sending the brominated butyl rubber liquid into the subsequent procedures. The stirrer seal of the bromination reaction kettle 2 is connected with the outlet of the nitrogen booster pump, and nitrogen pressurized by the nitrogen booster pump enters the stirrer seal from the outlet and then enters the bromination reaction kettle, so that the pressure of the whole reaction kettle is improved.

The staying kettle 3 is used for receiving the brominated butyl rubber solution from the bromination reaction kettle 2, and the brominated butyl rubber solution stays in the staying kettle for a certain time, so that the bromination reaction is more sufficient, and the bromination effect is improved. The feeding hole of the staying kettle 3 is arranged at the upper part or the top and is communicated with the bottom discharging hole of the bromination reaction kettle 2. The bottom of the staying kettle 3 is provided with a discharge hole for discharging the glue solution after staying reaction and sending the glue solution into the subsequent working procedures.

The upper part or the top of the neutralization kettle 4 is provided with a feed inlet which is communicated with a discharge port at the bottom of the staying kettle 3 and is used for receiving the glue solution from the staying kettle 3 and neutralizing the hydrogen bromide generated by the preorder reaction in the neutralization kettle. The bottom of the neutralization kettle 4 is provided with a discharge port which is communicated with a glue solution heating system in the subsequent solvent recovery system, in particular communicated with a feed port of a glue solution static mixer in the glue solution heating system, and the neutralized glue solution is sent to the subsequent solvent recovery system through the discharge port for subsequent treatment.

According to the invention, the neutralized glue solution enters a solvent recovery system to remove the solvent, so that the brominated butyl rubber and the recovered solvent are respectively obtained.

In the present invention, the solvent recovery system comprises:

a vapor-water mixer;

the glue static mixer is communicated with the feed inlet and the discharge outlet of the steam-water mixer; the feed inlet of the glue static mixer is also communicated with a neutralizing glue liquid outlet of the neutralizing system;

the feed inlet is communicated with the discharge outlet of the glue static mixer;

the feed inlet of the vacuum stripping tower is communicated with the discharge outlet of the flash tank;

and the air inlet is respectively communicated with the top exhaust port of the vacuum stripping tower and the top exhaust port of the flash tank.

Referring to fig. 3, fig. 3 is a schematic view showing the structure of the solvent recovery system according to the present invention. Wherein, 1 is the steam-water mixer, 2 is the glue static mixer, 3 is the flash tank, 4 is the vacuum stripping tower, 4a is first order vacuum stripping tower, 4b is second order vacuum stripping tower, 5 is the solvent recovery jar.

The steam-water mixer 1 is provided with a hot water inlet and a steam inlet, receives hot water and steam, and mixes the hot water and the steam in the steam-water mixer 1 to heat the hot water. Wherein, the hot water source can be the circulating hot water in the original production process of the brominated butyl rubber, one path of the hot water is sent into the steam-water mixer 1, and the rest circulating water still enters the flash tank along the original pipeline. The steam-water mixture obtained by mixing in the steam-water mixer 1 is discharged from a discharge port and sent to the subsequent working procedures.

The relevant operating parameters of the steam-water mixer 1 are as follows: the delivery flow of the hot water into the steam-water mixer 1 is preferably 60-100 t/h; in some embodiments of the invention, the flow rate is 60t/h, 80t/h or 100 t/h. The steam is preferably low pressure steam, more preferably 0.35MPa steam. The conveying flow of the steam introduced into the steam-water mixer 1 is preferably 1.5-3.2 t/h; in some embodiments of the invention, the flow rate is 1.8t/h, 2.5t/h or 3.0 t/h. The temperature of hot water is raised to 90-98 ℃ from 75-85 ℃ through a steam-water mixer 1; in some embodiments of the invention, the hot water temperature is increased to 90 ℃, 95 ℃, or 98 ℃.

The feed inlet of the glue static mixer 2 is communicated with the discharge outlet of the steam-water mixer 1 and is also communicated with a neutralizing glue liquid discharge outlet of the neutralizing system. In one embodiment of the invention, a feeding port of the glue static mixer 2 is communicated with a collecting pipe, the other end of the collecting pipe is communicated with two branch pipes, one branch pipe is communicated with the feeding port of the glue static mixer 2, the other branch pipe is communicated with a neutralizing glue solution outlet in a neutralizing system, and the heated hot water from the steam-water mixer 1 and the neutralizing glue solution from the neutralizing system are collected in a pipeline in advance and then are sent into the glue static mixer 2. The glue static mixer 2 receives the heated hot water from the steam-water mixer 1 and the neutralized glue solution from the neutralization system, so that the glue solution is mixed with the hot water, the temperature of the glue solution is increased, the glue solution is favorable for forming glue solution drops and a dispersed phase of water in a subsequent pipeline, after entering a subsequent flash tank, the glue solution is quickly gasified and flashed, pore channels are formed on the surface of the glue particles, the size of the glue particles is further reduced under the stirring action in the flash tank, the flash evaporation solvent removal effect is improved, the glue solution wall hanging phenomenon is also reduced, the solvent recovery efficiency is improved, the unit consumption of the whole solvent is reduced, the wall hanging and the blockage are reduced, the risks of pump blockage and shutdown are reduced, the production operation cycle of the brominated butyl rubber is ensured, and the whole production efficiency is improved.

The relevant technological parameters of the glue static mixer 2 are as follows: heating the glue solution from the original 50-60 ℃ to 68-85 ℃ by using a glue solution static mixer 2, and preferably heating to 70-85 ℃; in some embodiments of the invention, the temperature is raised to 68 ℃, 76 ℃ or 82 ℃.

The feed inlet of the flash tank 3 is communicated with the discharge outlet of the glue static mixer 2, and receives the heated glue solution from the glue static mixer 2 and carries out flash evaporation. The flash evaporation aims at separating rubber from glue solution and recovering solvent, and in the process, the rubber undergoes several stages of dispersion, heat absorption, vaporization and the like, and can be divided into three stages: dispersing the glue solution into glue drops in a medium, gasifying the solvent to form oil-containing particles and solid colloidal particles. Before entering a flash tank, the glue solution is heated by hot water through a glue solution heating system (namely a steam-water mixer 1 and a glue solution static mixer 2) in advance, and forms glue solution drops and a dispersed phase of water in a subsequent pipeline, after entering the subsequent flash tank, the glue solution is quickly gasified and flashed, pore channels are formed on the surface of the colloidal particles, the size of the colloidal particles is further reduced under the stirring action in the flash tank, so that the solvent (hexane) is effectively removed, the effect of flash evaporation solvent removal is improved, the phenomenon of glue solution wall hanging is also reduced, the solvent recovery efficiency is improved, the unit consumption of the whole solvent is reduced, the wall hanging and the blockage are reduced, and the risks of pump blockage and shutdown are reduced. The top of the flash tank 3 is also provided with an exhaust port for discharging solvent gas generated during the flash process.

A nozzle and a baffle are arranged in the flash tank 3, wherein the nozzle and the feeding jet orifice are used for receiving the material from the previous working procedure and spraying the material into the flash tank; the baffle is used for improving the mixing effect of flash tank stirring, and the hexane solvent in the glue is easier to flash. In the prior art, the structure of the nozzle and the baffle in the flash tank is shown in fig. 4, and fig. 4 is a schematic structural diagram of the flash tank in the prior art; wherein, the angle alpha of the glue spraying opening (namely the included angle between the nozzle and the inner wall of the flash tank) is vertical, the shape of the nozzle 3a is a right-angle fold line shape, and the baffle 3b is a cubic baffle. The present invention preferably improves the internal configuration of the flash tank 3, as shown in fig. 5, fig. 5 is a schematic structural view of the flash tank employed in some embodiments of the present invention; wherein the angle α of the glue spraying opening is less than 90 °, more preferably 60 °, and the shape of the nozzle 3a is linear, meanwhile, the baffle 3b is a triangular prism baffle, the shape is shown in fig. 6, and fig. 6 is a schematic diagram of the baffle in the flash tank. The angle of the glue spraying opening of the nozzle in the flash tank is changed (less than 90 degrees, preferably 60 degrees), the baffle form is changed from a single piece type to a triangular prism baffle, the structure of the above form can enable the feeding material to be in the flow field of the flash tank, the flow speed is improved at the point with higher flow speed, the size of liquid drops during flash evaporation is reduced, the solvent diffusion in the later stage of flash evaporation is facilitated, the uniform dispersion of glue liquid is improved, the wall hanging is reduced, the flash evaporation solvent removal effect is improved, the blockage is reduced, the operation time is improved, and the production efficiency is improved.

The operating parameters of the flash tank 3 are as follows: the operation temperature is preferably 80-120 ℃. After flash evaporation, gas generated by solvent gasification is discharged from the top, and the BIIR colloidal particle-water mixture is enriched at the bottom of the tank, discharged from a discharge port and enters the next working procedure.

The feed inlet of the vacuum stripping column 4 communicates with the discharge outlet of the flash tank 3 and receives the BIIR crumb-water mixture from the flash tank 3 and strips it. The operation temperature of the vacuum stripping tower 4 is preferably 68-100 ℃. The top of the vacuum stripping tower 4 is also provided with an exhaust port for exhausting the solvent gas generated in the flash evaporation process.

In an embodiment of the present invention, the flash tank 3 and the vacuum stripping tower 4 are further provided with a flash tank pump 3c, and the discharge port of the flash tank 3 is communicated with the feed port of the vacuum stripping tower 4 through the flash tank pump 3c, so as to pump the glue solution enriched at the bottom of the flash tank 3 into the vacuum stripping tower 4.

In one embodiment of the invention, the vacuum stripper 4 is a two-stage vacuum stripper, in particular comprising two first vacuum strippers 4a and a second vacuum stripper 4b connected in series with each other. The operating temperature of the primary vacuum stripping tower is preferably 75-100 ℃, and the operating pressure is preferably 550-670 mmHg; the operation temperature of the secondary vacuum stripping tower is preferably 68-80 ℃, and the operation pressure is preferably 200-250 mmHg. In an embodiment of the present invention, the first-stage vacuum stripping tower 4a and the second-stage vacuum stripping tower 4b are further provided with a first-stage stripping pump 4c, and the discharge port of the first-stage vacuum stripping tower 4a is communicated with the feed port of the second-stage vacuum stripping tower 4b through the first-stage stripping pump 4c, so as to pump the glue solution enriched at the bottom of the first-stage vacuum stripping tower 4a into the second-stage vacuum stripping tower 4 b.

And (3) further removing the solvent in the glue solution material by steam stripping in the vacuum stripping tower 4, discharging the solvent gas from the top, enriching the BIIR colloidal particle-water mixture at the bottom of the tower, and sending the mixture into a post-treatment unit for dehydration and drying to obtain brominated butyl rubber, and further preparing the brominated butyl rubber into a rubber product. In an embodiment of the present invention, a secondary stripping pump 4d is further disposed between the vacuum stripping tower 4 and the post-treatment unit, and a discharge port of the vacuum stripping tower 4 is communicated with a feed port of the post-treatment unit through the secondary stripping pump 4d, so that the colloidal particle-water mixture enriched at the bottom of the vacuum stripping tower 4 is pumped into the post-treatment unit for post-treatment drying.

And the air inlet of the solvent recovery tank 5 is respectively communicated with the top exhaust port of the vacuum stripping tower 4 and the top exhaust port of the flash tank 3, and the solvent gas discharged from the top of the flash tank 3 and the solvent gas discharged from the top of the vacuum stripping tower 4 are recovered to obtain a hexane solvent, and the hexane solvent can be reused in the production of the brominated butyl rubber.

The operation process of the integral solvent recovery system is as follows:

hot water and steam are respectively introduced into the steam-water mixer, the obtained steam-water mixture is fed into the glue static mixer, meanwhile, the neutralized glue solution generated by the neutralization system is fed into the glue static mixer, the steam-water mixture and the neutralized glue solution are mixed in the glue static mixer to heat the glue solution, the obtained heated glue solution is sequentially fed into a flash tank for flash evaporation and a vacuum stripping tower for steam stripping, solvents removed in the flash evaporation and steam stripping processes are respectively discharged through a top exhaust port of the flash tank and a top exhaust port of the stripping tower and enter a solvent recovery tank for recovering the solvents, and the brominated butyl rubber is obtained at the bottom of the vacuum stripping tower.

The production process of the brominated butyl rubber provided by the invention has the following beneficial effects:

(1) the solvent recovery system is improved, a glue solution temperature rising system (a steam-water mixer and a glue solution static mixer) is arranged in front of a flash tank, so that the glue solution is mixed with hot water, the running conditions of the hot water and steam are controlled, the temperature of the glue solution is raised to a specific degree, the glue solution is favorable for forming a glue solution droplet and a water dispersion phase in a subsequent pipeline, after the glue solution enters the subsequent flash tank, the glue solution is quickly gasified and flash evaporated, pore channels are formed on the surfaces of colloidal particles, the size of the colloidal particles is further reduced under the stirring action in the flash tank, the flash evaporation solvent removal effect is improved, the glue solution wall hanging phenomenon is also reduced, the solvent recovery efficiency is improved, the unit consumption of the whole solvent is reduced, the wall hanging and the blockage are reduced, the risks of pump blockage and shutdown are reduced, the production running period.

(2) The flash tank internal structure is improved, the nozzle and the baffle are improved, solvent diffusion at the later stage of flash evaporation is facilitated, uniform dispersion of glue solution is improved, wall hanging is reduced, the effect of flash evaporation solvent removal is improved, blocking is reduced, the operation time is prolonged, and production efficiency is improved.

(3) The pre-order bromination unit is improved, a nitrogen pressurization system is added, the overall pressure of the glue solution is increased by 10-20 kPa, the pressure drop generated by a back-way glue solution heating system is met, and the operation stability of the overall device is improved, so that the solvent removal effect is improved, the operation time is improved, and the production efficiency is improved.

In the process provided by the invention, the flash evaporation effect is improved by the aspects, so that the hexane solvent recovery effect of the whole system is improved, the unit consumption of normal hexane in the production of brominated butyl rubber is reduced, the content of non-methane total hydrocarbons in the post-treated tail gas is reduced, and the operation of a tail gas treatment device is facilitated and the treatment cost is reduced. Meanwhile, the wall hanging and blocking of glue solution are reduced, so that the abnormal shutdown frequency is reduced, the operable time (pump blocking period) is prolonged, the production cost increase caused by abnormal shutdown is reduced, and the overall production efficiency is improved.

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

Comparative example 1

Preparing brominated butyl rubber and recovering solvent according to the prior process flow and the conventional operating conditions shown in figure 1, wherein the process flow is as follows:

s1, preparing sol: carrying out cationic polymerization on isobutene and isoprene to obtain IIR basic colloidal particle water, conveying the IIR basic colloidal particle water to a halogenated feeding storage tank through a colloidal particle water pump, carrying out extrusion dehydration through a vibrating screen and a screw machine, and carrying out gel concentration preparation through cold and hot hexane to obtain sol (the concentration is 20 wt%) with a set concentration.

S2, bromination-neutralization: feeding the sol into a bromination reaction kettle, and carrying out bromination reaction on the sol and introduced bromine to obtain a brominated glue solution; then the solution is sent into a neutralization unit (sequentially passes through a retention kettle and a neutralization reaction kettle, and stays in the retention kettle for 10min), and neutralization solution (sodium hydroxide solution) is adopted to neutralize the residual bromine and hydrogen bromide, so as to obtain neutralization glue solution.

S4, flash evaporation: the neutralized glue solution (at 55 ℃) is sent into a flash tank (at the flow rate of 56t/h) for flash evaporation, and the operating temperature of the flash tank is 100 ℃.

S5, stripping: and sequentially feeding the glue solution enriched at the bottom of the flash tank into a primary vacuum stripping tower (the operation temperature is 85 ℃ and the pressure is 600mmHg) and a secondary vacuum stripping tower (the operation temperature is 72 ℃ and the pressure is 225mmHg) for stripping. And (3) sending the glue mixture obtained at the bottom of the stripping tower into a post-treatment unit for drying and dehydration to obtain the brominated butyl rubber.

S6, solvent recovery: in the operation process, the hexane gas discharged from the top of the flash tank and the stripping tower is collected in the solvent recovery tank to obtain a hexane product.

The process is operated according to the above, and the colloidal particle water mixture in the secondary vacuum stripping tower is sampled and detected for multiple times, and the result shows that the hexane content is 178-225 ppm, which indicates that the hexane unit consumption is high.