阅读说明：本技术 一种用于聚碳酸酯工业化生产的碳酸二苯酯回收装置及方法 (Diphenyl carbonate recovery device and method for industrial production of polycarbonate ) 是由 龙升全 羊德文 吴冬萍 张利 周辉 付家友 唐川 杨应振 熊志坚 郭克军 王焱锋 于 2021-08-16 设计创作，主要内容包括：本发明提供一种用于聚碳酸酯工业化生产的碳酸二苯酯回收装置及方法,包括DPC精馏塔,DPC精馏塔的一侧中部进料端通过连接管道连接有苯酚回收物料管,所述苯酚回收物料管与苯酚回收系统的出液端连通,且连接管与DPC精馏塔的连接处还安装有进料阀,DPC精馏塔的顶部出料端连接有苯酚回收管,DPC精馏塔的出料端还连通有用于回收DPC的DPC回收管,本发明通过设置的DPC精馏塔可以对苯酚回收系统注入的原料进行精馏,利用膜式汽化器对闪蒸后的物料进行汽化分离,使得正在聚碳酸酯生产过程中可以较大程度上对碳酸二苯酯进行回收,并且通过设置的回收装置可以对DPC的回收率高达98％以上,这样有效减少了DPC的损耗,从而降低了整个聚碳酸酯装置的DPC消耗。(The invention provides a diphenyl carbonate recovery device and a method for polycarbonate industrial production, which comprises a DPC rectifying tower, wherein the middle feed end at one side of the DPC rectifying tower is connected with a phenol recovery material pipe through a connecting pipeline, the phenol recovery material pipe is communicated with the liquid outlet end of a phenol recovery system, a feed valve is further installed at the connecting part of a connecting pipe and the DPC rectifying tower, the discharge end at the top of the DPC rectifying tower is connected with a phenol recovery pipe, and the discharge end of the DPC rectifying tower is also communicated with a DPC recovery pipe for recovering DPC. This effectively reduces the loss of DPC, and thus the DPC consumption of the entire polycarbonate plant.)

1. The diphenyl carbonate recovery device for the industrial production of polycarbonate comprises a DPC rectifying tower (1) and is characterized in that a feed end in the middle of one side of the DPC rectifying tower (1) is connected with a DPC recovery material pipe (13) through a connecting pipeline, the DPC recovery material pipe (13) is communicated with a liquid outlet end of a phenol recovery system, a feed valve (11) is further installed at the connecting position of the connecting pipeline and the DPC rectifying tower (1), a discharge end at the top of the DPC rectifying tower (1) is connected with a phenol recovery pipe (12), a DPC recovery pipe (14) for recovering DPC is further communicated with a discharge end of the DPC rectifying tower (1), a liquid outlet end of the DPC rectifying tower (1) is connected with a tower kettle pump (2) through a pipeline, the tower kettle pump (2) is communicated with a liquid inlet end of a flash tank (3) through a pipeline, and a liquid outlet end of the flash tank (3) is communicated with a liquid inlet end of a membrane vaporizer (8) through a pipeline, the liquid outlet end of the membrane vaporizer (8) is communicated with a DPC recovery tank (6) through a pipeline, the waste liquid outlet end of the membrane vaporizer (8) is communicated with a waste liquid collection tank (7) through a pipeline, the DPC recovery tank (6) is connected with a DPC recovery pump (5) through a pipeline, the liquid outlet end of the DPC recovery pump (5) is communicated with a feed valve (11) through a pipeline, the liquid outlet end of the waste liquid collection tank (7) is communicated with a waste liquid pump (9) through a pipeline, and the liquid outlet end of the waste liquid pump (9) is communicated with a waste liquid removal discharge pipe (10).

2. The diphenyl carbonate recycling device for industrial production of polycarbonate according to claim 1, wherein: and the phenol recovery pipe (12) is communicated with the liquid inlet end of the phenol recovery system.

3. The diphenyl carbonate recycling device for industrial production of polycarbonate according to claim 1, wherein: the membrane vaporizer (8) is installed at the top of mounting bracket (4), the mid-mounting of mounting bracket (4) has horizontal mounting panel (41), the top and DPC recovery tank (6) and waste liquid collection tank (7) fixed connection of horizontal mounting panel (41).

4. The diphenyl carbonate recycling device for industrial production of polycarbonate according to claim 1, wherein: the bottom of flash tank (3) is installed a plurality of supports (31) that are used for supporting it, the regulation stabilizer blade is installed to the bottom of support (31).

5. The diphenyl carbonate recycling device for industrial production of polycarbonate according to claim 1, wherein: and control valves are arranged in the middle of a connecting pipeline between the tower kettle pump (2) and the flash tank (3), in the middle of a connecting pipeline between the DPC recovery pump (5) and the feed valve (11) and in the middle of the waste liquid removal discharge pipe (10).

6. The diphenyl carbonate recycling device for industrial production of polycarbonate according to claim 1, wherein: the weight percentages (wt%) of the materials of the phenol recovery system are respectively as follows: 3% of phenol, 87% of DPC and 10% of high-boiling-point substances (containing BPA), wherein the flow rates of materials are as follows: 1600 kg/h.

7. The diphenyl carbonate recycling device for industrial production of polycarbonate according to claim 1, wherein: the weight percentages (wt%) of the recovered DPC in the DPC rectifying tower (1) are respectively as follows: phenol 0.05%, DPC 99.95% and high boiler (BPA-containing) 0, wherein the flow rates of the materials are: 1220 kg/h.

8. The diphenyl carbonate recycling device for industrial production of polycarbonate according to claim 1, wherein: the weight percentages (wt%) of phenol extraction components in the DPC rectifying tower (1) overhead phenol recovery pipe (12) are respectively as follows: phenol 40%, DPC 60% and high boiling point substance (containing BPA)0, wherein the flow rate of the materials is as follows: 30 kg/h.

9. The diphenyl carbonate recycling device for industrial production of polycarbonate according to claim 1, wherein: the weight percentages (wt%) of materials in a rectifying liquid outlet end (15) at the bottom of the DPC rectifying tower (1) are respectively as follows: phenol 0, DPC 55% and high boiling point (BPA-containing) 45%, wherein the flow rates of the materials are: 350 kg/h.

10. A diphenyl carbonate recycling method for industrial production of polycarbonate, comprising the diphenyl carbonate recycling device for industrial production of polycarbonate, according to any one of claims 1 to 9, characterized by comprising the following steps:

s1, debugging and installing the recovery device, and communicating the phenol recovery pipe (12) with the liquid outlet end of the phenol recovery system;

s2, recovering the diphenyl carbonate by using the rectification process of the DPC rectification tower (1) and the vaporization technology of the membrane vaporizer (8);

s3, carrying out statistics on the recovery rate of the DPC in the recovery process, and carrying out secondary debugging on a recovery device;

and S4, the waste liquid in the waste liquid discharge pipe (10) is treated, so that energy is saved and emission is reduced.

Technical Field

The invention belongs to the technical field of polycarbonate production, and particularly relates to a diphenyl carbonate recovery device and method for industrial production of polycarbonate.

Background

Polycarbonate (abbreviated as PC in english) is a high molecular polymer containing carbonate groups in its molecular chain, and is classified into various types such as aliphatic, aromatic, aliphatic-aromatic, and the like, depending on the structure of the ester groups. Among them, aliphatic and aliphatic-aromatic polycarbonates have limited their use as engineering plastics due to their low mechanical properties.

At present, two main methods for the industrial production of polycarbonate are available, one is a phosgene method, and the other is non-phosgene. The non-phosgene method adopts bisphenol A and diphenyl carbonate (DPC) as raw materials to prepare Polycarbonate (PC) through ester exchange and polycondensation, in the production process, phenol generated in the reaction process needs to be continuously extracted, in the process, a small part of raw material bisphenol A, raw material DPC and generated oligomers are extracted together with the phenol and enter a phenol recovery system, the phenol is separated and recovered in the phenol recovery system and then enter the DPC recovery system to recover the DPC, in the existing DPC recovery technology, the recovery rate of the DPC is lower than 80 percent, a large amount of DPC is discharged into a waste liquid treatment system together with waste liquid to be treated, the consumption of the DPC is increased, meanwhile, certain pollution is caused to the environment, and the production cost of enterprises is increased invisibly.

Disclosure of Invention

The invention aims to provide a diphenyl carbonate recovery device and a diphenyl carbonate recovery method for industrial production of polycarbonate, and aims to solve the problems that in the DPC recovery technology in the prior art, the recovery rate of DPC is lower than 80%, a large amount of DPC is discharged into a waste liquid treatment system along with waste liquid for treatment, the consumption of DPC is increased, meanwhile, certain pollution is caused to the environment, and the production cost of enterprises is increased invisibly.

In order to achieve the purpose, the invention provides the following technical scheme: a diphenyl carbonate recovery device for industrial production of polycarbonate comprises a DPC rectifying tower, wherein a feed end in the middle of one side of the DPC rectifying tower is connected with a DPC recovery material pipe through a connecting pipeline, the DPC recovery material pipe is communicated with a liquid outlet end of a phenol recovery system, a feed valve is further installed at the connection position of the connecting pipe and the DPC rectifying tower, a discharge end at the top of the DPC rectifying tower is connected with a phenol recovery pipe, a discharge end of the DPC rectifying tower is further communicated with a DPC recovery pipe for recovering DPC, a liquid outlet end of the DPC rectifying tower is connected with a tower kettle pump through a pipeline, the tower kettle pump is communicated with a liquid inlet end of a flash tank through a pipeline, a liquid outlet end of the flash tank is communicated with a liquid inlet end of a membrane vaporizer through a pipeline, a liquid outlet end of the membrane vaporizer is communicated with a DPC recovery tank through a pipeline, a liquid waste end of the membrane vaporizer is communicated with a liquid waste collection tank through a pipeline, the DPC recovery tank is connected with a DPC recovery pump through a pipeline, the liquid outlet end of the DPC recovery pump is communicated with the feeding valve through a pipeline, the liquid outlet end of the waste liquid collection tank is communicated with a waste liquid pump through a pipeline, and the liquid outlet end of the waste liquid pump is communicated with a waste liquid discharge pipe.

In order to communicate the recovery device with the phenol recovery system, it is preferable that the phenol recovery pipe is communicated with a liquid inlet end of the phenol recovery system.

In order to integrate and modularize the recovery device, as a preferable mode of the invention, the membrane vaporizer is mounted on the top of a mounting frame, a transverse mounting plate is mounted in the middle of the mounting frame, and the top of the transverse mounting plate is fixedly connected with the DPC recovery tank and the waste liquid collecting tank.

In order to rapidly support and adjust the flash tank, as a preferred mode of the invention, the bottom of the flash tank is provided with a plurality of supports for supporting the flash tank, and the bottom ends of the supports are provided with adjusting feet.

In order to enable personnel to conveniently debug the recovery device, as a preferable mode of the invention, control valves are arranged in the middle of a connecting pipeline between the tower kettle pump and the flash tank, in the middle of a connecting pipeline between the DPC recovery pump and the feed valve and in the middle of the waste liquid discharge pipe.

In order to connect the phenol recovery system to the recovery device and recover the materials, as a preferred aspect of the present invention, the weight percentages (wt%) of the materials of the phenol recovery system are: 3% of phenol, 87% of DPC and 10% of high-boiling-point substances (containing BPA), wherein the flow rates of materials are as follows: 1600 kg/h.

In order to make the DPC rectifying tower used for rectifying the material, as a preferred mode of the invention, the weight percentages (wt%) of the recovered DPC in the DPC rectifying tower are respectively: phenol 0.05%, DPC 99.95% and high boiler (BPA-containing) 0, wherein the flow rates of the materials are: 1220 kg/h.

In order to verify the DPC loss rate at the top of the DPC rectifying tower, as a preferable mode of the invention, the weight percentages (wt%) of phenol extracted components in a phenol recovery pipe at the top of the DPC rectifying tower are respectively as follows: phenol 40%, DPC 60% and high boiling point substance (containing BPA)0, wherein the flow rate of the materials is as follows: 30 kg/h.

In order to verify the recovery rate of the phenol in the DPC rectifying tower, as a preferred mode of the invention, the weight percentages (wt%) of the materials in the rectifying liquid end at the tower bottom of the DPC rectifying tower are respectively as follows: phenol 0, DPC 55% and high boiling point (BPA-containing) 45%, wherein the flow rates of the materials are: 350 kg/h.

A diphenyl carbonate recovery method for industrial production of polycarbonate comprises any one of the diphenyl carbonate recovery devices for industrial production of polycarbonate, and the specific steps are as follows:

s1, debugging and installing the recovery device, and communicating the phenol recovery pipe with the liquid outlet end of the phenol recovery system;

s2, recovering the diphenyl carbonate by using the rectification process of the DPC rectification tower and the vaporization technology of the membrane vaporizer;

s3, carrying out statistics on the recovery rate of the DPC in the recovery process, and carrying out secondary debugging on a recovery device;

and S4, treating the waste liquid in the waste liquid discharge pipe, and saving energy and reducing emission.

Compared with the prior art, the invention has the beneficial effects that:

1) raw materials injected by a phenol recovery system can be rectified by the arranged DPC rectifying tower, materials after flash evaporation are vaporized and separated by the membrane vaporizer, DPC can be recovered to a large extent in the production process of polycarbonate, and the recovery rate of DPC can reach more than 98% by the arranged recovery device, so that the consumption of DPC is effectively reduced, the DPC consumption of the whole polycarbonate device is reduced, the production input cost of an enterprise is reduced, meanwhile, technical support is provided for industrial energy-saving and environment-friendly production of polycarbonate, and the method has important creative significance in the production industry of polycarbonate;

2) through retrieving jar DPC, waste liquid collection tank and membrane vaporizer all install on the mounting bracket for possible integration and modularization of recovery unit, reduce recovery unit's space and occupy, make polycarbonate manufacturing enterprise can be more convenient assemble the use, and can carry out temporary storage to the waste liquid that produces among the recovery process through the waste liquid collection tank that sets up, make waste water carry out unified processing after going waste liquid discharge pipe discharge, reach energy saving and emission reduction's effect.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a flow chart of the present invention;

FIG. 2 is a partial schematic structural view of the present invention;

FIG. 3 is a side view of FIG. 2 of the present invention;

FIG. 4 is a schematic diagram of the DPC rectifying tower structure of the present invention;

in the figure: 1. a DPC rectifying tower; 11. a feed valve; 12. a phenol recovery pipe; 13. a phenol recovery material pipe; 14. a DPC recovery pipe; 15. the liquid end is extracted by rectification; 16. a reboiler; 17. a condenser; 18. a condensate tank; 2. a tower kettle pump; 3. a flash tank; 31. a support; 4. a mounting frame; 41. a transverse mounting plate; 5. a DPC recovery pump; 6. a DPC recovery tank; 7. a waste liquid collection tank; 8. a membrane vaporizer; 9. a waste liquid pump; 10. to a waste liquid discharge pipe.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Referring to fig. 1-4, the present invention provides the following technical solutions: the diphenyl carbonate recovery device for industrial production of polycarbonate comprises a DPC rectifying tower 1, wherein a DPC recovery material pipe 13 is connected to a feed end in the middle of one side of the DPC rectifying tower 1 through a connecting pipeline, the DPC recovery material pipe 13 is communicated with a liquid outlet end of a phenol recovery system, a feed valve 11 is further installed at the connecting part of the connecting pipeline and the DPC rectifying tower 1, a phenol recovery pipe 12 is connected to a discharge end at the top of the DPC rectifying tower 1, the phenol recovery pipe 12 is connected with a condenser 17 through a pipeline, condensate condensed by the condenser 17 enters a condensate tank 18, part of the condensate in the condensate tank 18 is pumped into the phenol recovery system through a pump to recover phenol, and part of the condensate enters the top of the DPC rectifying tower 1 to flow back, and the ratio of the backflow amount to the produced amount (the amount entering the phenol recovery system) is 2-10. Besides, a reboiler 16 communicated with the interior of the DPC rectifying tower 1 is arranged on one side of the DPC rectifying tower 1, and the reboiler 16 is indirectly heated by adding a heating medium to provide heat required by the whole rectifying system. The discharge end of the DPC rectifying tower 1 is further communicated with a DPC recovery pipe 14 for recovering DPC, the liquid outlet end of the DPC rectifying tower 1 is connected with a tower kettle pump 2 through a pipeline, the tower kettle pump 2 is communicated with the liquid inlet end of the flash tank 3 through a pipeline, the liquid outlet end of the flash tank 3 is communicated with the liquid inlet end of the membrane vaporizer 8 through a pipeline, the liquid outlet end of the membrane vaporizer 8 is communicated with a DPC recovery tank 6 through a pipeline, the waste liquid outlet end of the membrane vaporizer 8 is communicated with a waste liquid collecting tank 7 through a pipeline, the DPC recovery tank 6 is connected with a DPC recovery pump 5 through a pipeline, the liquid outlet end of the DPC recovery pump 5 is communicated with a feed valve 11 through a pipeline, the liquid outlet end of the waste liquid collecting tank 7 is communicated with a waste liquid pump 9 through a pipeline, and the liquid outlet end of the waste liquid pump 9 is communicated with a waste liquid discharge pipe 10.

In this embodiment: the phenol recovery pipe 12 is communicated with the liquid inlet end of the phenol recovery system.

Specifically, make phenol recovery pipe 12 and phenol recovery system's feed liquor end communicate through flange joint spare for recovery unit and phenol recovery system realize being connected, and personnel can control the flow that phenol recovery system pours into through feed valve 11 simultaneously, can be better control the recovery.

In this embodiment: the membrane vaporizer 8 is arranged on the top of the mounting frame 4, the middle part of the mounting frame 4 is provided with a transverse mounting plate 41, and the top of the transverse mounting plate 41 is fixedly connected with the DPC recovery tank 6 and the waste liquid collecting tank 7.

Specifically, utilize the screw rod can retrieve DPC recovery tank 6 and waste liquid collection tank 7 horizontal installation on the horizontal mounting panel 41 at mounting bracket 4 middle part, can install diaphragm type vaporizer 8 in the top of mounting bracket 4 fast for recovery unit can accomplish miniaturization and modularization, does benefit to the polycarbonate enterprise and installs, reduces the production input of enterprise.

In this embodiment: the bottom of flash tank 3 is installed a plurality of supports 31 that are used for supporting it, the bottom of support 31 is installed and is adjusted the stabilizer blade.

Specifically, support 31 through the installation can support the installation fast to flash tank 3 fixed to the regulation stabilizer blade that can set up can adjust the level of flash tank 3, ensures that flash tank 3 can carry out the flash distillation to the material and handle.

In this embodiment: and control valves are arranged in the middle of a connecting pipeline between the tower kettle pump 2 and the flash tank 3, in the middle of a connecting pipeline between the DPC recovery pump 5 and the feed valve 11 and in the middle of the waste liquid removal discharge pipe 10.

The utility model discloses a phenol recovery device, including phenol recovery device, control valve, the pipeline is connected with the control valve, the control valve is connected with the pipeline, the pipeline is connected with the control valve, the control valve is connected with the pipeline, the pipeline is connected with the control valve, the pipeline, the control valve is connected with the control valve.

In this embodiment: the weight percentages (wt%) of the materials of the phenol recovery system are respectively as follows: 3% of phenol, 87% of DPC and 10% of high-boiling-point substances (containing BPA), wherein the flow rates of materials are as follows: 1600 kg/h.

Specifically, the material composition in the phenol recovery system is detected in advance, and the weight percentage of each component is calculated to verify the phenol recovery rate and the DPC loss rate later.

In this embodiment, the weight percentages (wt%) of the recovered DPC in the DPC rectifying column 1 are: phenol 0.05%, DPC 99.95% and high boiler (BPA-containing) 0, wherein the flow rates of the materials are: 1220 kg/h.

Specifically, the DPC rectifying tower 1 is arranged to rectify the materials, the materials are detected again after rectification, the recovery of phenol is obviously improved, and the loss of DPC is reduced, which means that the flow rate of the materials is controlled to 1150-1220 kg/h.

In this embodiment: the weight percentages (wt%) of phenol extraction components in the DPC rectifying tower 1 overhead phenol recovery pipe 12 are respectively as follows: phenol 40%, DPC 60% and high boiling point substance (containing BPA)0, wherein the flow rate of the materials is as follows: 30 kg/h.

Specifically, after the DPC rectifying tower 1 recovers and processes the materials, the phenol recovery pipe 12 can inject phenol into the phenol recovery system again, and then secondary rectification recovery can be performed, so that the purity and recovery amount of phenol recovery are improved, and DPC generated after rectification can be recovered through the arranged DPC recovery pipe 14.

In this embodiment: the weight percentages (wt%) of the materials in the distillation liquid outlet end 15 of the bottom of the DPC rectifying tower 1 are respectively as follows: phenol 0, DPC 55% and high boiling point (BPA-containing) 45%, wherein the flow rates of the materials are: 350 kg/h.

Specifically, can pump into flash tank 3 once more with the material after DPC rectifying column 1 rectification through the tower cauldron pump 2 that sets up, through rapid boiling vaporization to inject into membrane vaporizer 8 after the double-phase separation, carry out vaporization separation to it, rethread DPC recovery tank 6 is retrieved PDC, increases the rate of recovery of PDC, utilizes waste liquid collection tank 7 to store the collection to the waste liquid simultaneously.

A diphenyl carbonate recovery method for industrial production of polycarbonate comprises the steps of utilizing any one of the diphenyl carbonate recovery devices for industrial production of polycarbonate, and the specific steps are as follows:

s1, debugging and installing the recovery device, and communicating the phenol recovery pipe 12 with the liquid outlet end of the phenol recovery system;

s2, recovering the diphenyl carbonate by using the rectification process of the DPC rectification tower 1 and the vaporization technology of the membrane vaporizer 8;

s3, carrying out statistics on the recovery rate of the DPC in the recovery process, and carrying out secondary debugging on a recovery device;

and S4, the waste liquid in the waste liquid discharge pipe 10 is treated, so that energy is saved and emission is reduced.

Specifically, after being detected by testers, the weight percentages (wt%) of the materials in the DPC recovery tank 6 are respectively as follows: phenol 0, DPC 85% and high boiling point substances (containing BPA) 15%, wherein the flow rates of the materials are as follows: 200 kg/h;

the weight percentages (wt%) of the materials in the waste liquid collecting tank 7 are respectively: phenol 0, DPC 15% and high boiling point substances (containing BPA) 85%, wherein the flow rates of the materials are as follows: 150 kg/h.

Finally, it should be noted that: 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 changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.